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Energy Research & Social Science 90 (2022) 102594
2214-6296/© 2022 Published by Elsevier Ltd.
Taking it outside: Exploring social opposition to 21 early-stage experiments
in radical climate interventions
Sean Low
*
, Chad M. Baum, Benjamin K. Sovacool
Department of Business Development and Technology, Aarhus University, Denmark
ARTICLE INFO
Keywords:
Climate experiments
Climate governance
Solar geoengineering
Carbon dioxide removal
Greenhouse gas removal
Solar radiation management
ABSTRACT
Large-scale and highly experimental interventions are being considered as strategies to address climate change.
These include carbon dioxide removal approaches that are becoming a key pillar of post-Paris assessment and
governance, as well as the more controversial suite of solar geoengineering methods. In this paper, we ask: Who
defends and opposes these experiments, and why? After screening 44 early-stage experiments, we conduct a
qualitative comparative analysis of 21 of them in ve areas: ocean fertilization, marine cloud brightening,
stratospheric aerosol injection, ice protection, and enhanced weathering. We develop a common framework of
analysis, treating experiments as sites in which the risks and appropriate governance of early-stage science and
technology are envisioned and disputed among scientists and other social groups. Our contribution is to map and
explain the key issues of contention (why), actors (who), and tactics (how) that have shaped opposition across
these linked elds of experimentation and technological development, from the 1990s till today. In doing so, we
build upon and connect past studies on particular climate experiments and develop insights relevant to gover-
nance outlooks perceptions, discourses, and intents surrounding immature but potentially crucial climate
technologies.
1. Introduction
A series of deliberate, large-scale and highly experimental in-
terventions are being considered as strategies to address climate change.
These include carbon removal (or negative emissions) approaches that
are becoming a key pillar of post-Paris assessment and governance, as
well as the more controversial suite of solar geoengineering (sunlight
reecting methods, or solar radiation management). In this paper, we
focus on the most radical and early-stage climate interventions in terms
of technological readiness levels (TRLs) and social acceptance, and
which remain at a handful of small-scale experiments. Early-stage ex-
periments pose minor physical and environmental impacts - yet many
have been met with substantial and ongoing opposition. Contestation
over these experiments raises questions concerning how scientic
assessment is conducted, and public consent sought, within the charged
politics of geoengineering as well as climate governance.
Climate geoengineering, or ‘deliberate, large scale interventions in
the global climate’, is the original umbrella concept for carbon removal
and solar geoengineering. Shepherd et al. [1] provide a landmark
assessment report; Keith [2] and Oomen and Meiske [3] trace a history
that stretches into Cold War-era environmental interventions. The term's
invocation still shapes how experiments are designed and opposed. More
recently, carbon removal and solar geoengineering have become sepa-
rately assessed [4,5]. Carbon removal is becoming normalized as an
expanding range of ‘nature-based’ and technological approaches, where
incoming practitioners often eschew the controversial geoengineering
label or emphasize the ‘naturalness’ of their intervention technique
[6–8]. Researchers have been more open to retaining the specic
phrasing of ‘solar’ geoengineering for sunlight-reecting methods. But
opposition led by key environmental non-governmental organizations
(ENGOs) still invokes critiques of the underlying rationales for
geoengineering.
In this paper, we ask: Who defends and opposes early-stage experi-
ments for radical climate interventions, and why? The signicance of
this inquiry belies the current stage of small-scale experiments in fringe
corners of climate technology development. We expose how academics,
technologists, societal groups, and ENGOs contest conceptions of co-
benets and risks for society and industry on potentially game-
changing climate strategies, through the design and governance of
foundational experiments.
* Corresponding author at: Birk Centerpark 15, 7400 Herning, Denmark.
E-mail address: sean.low@btech.au.dk (S. Low).
Contents lists available at ScienceDirect
Energy Research & Social Science
journal homepage: www.elsevier.com/locate/erss
https://doi.org/10.1016/j.erss.2022.102594
Received 19 November 2021; Received in revised form 21 March 2022; Accepted 23 March 2022
Energy Research & Social Science 90 (2022) 102594
2
After screening an initial 44 prospective experiments, we conduct a
deeper qualitative comparative analysis of 21 experiments in ve low-
TRL carbon removal and solar geoengineering approaches: ocean
fertilization, marine cloud brightening, stratospheric aerosol injection,
ice protection, and enhanced weathering. Beyond breadth of technol-
ogy, we aim for a long arc: the past 30 years, from the 1990s and the
birth of the ‘geoengineering’ label, till the present day.
In Section 2, we develop a common framework of analysis, treating
experiments as sites in which the risks and appropriate governance of
early-stage science and technology are envisioned and disputed among
scientists and other social groups (e.g. [9]). Section 3 clusters experi-
ments separately by technology; Section 4 derives generalizable in-
sights. Our unprecedented scope allows us to highlight the common
issues (why), actors (who), and tactics (how) that have shaped experi-
ment design and opposition across these linked elds of technological
development, and may continue to do so in the future (similar to [10]).
We orient our inquiry from ‘controversy studies’ within the wider
discipline of science and technology studies, where contestation pro-
vides an opportunity to examine politics hidden in technical and tech-
nocratic assessment [10–16]. Controversies over scientic processes or
new technologies with challenging societal implications offer focal sites
where actors can contest their direction of travel - creating communities,
terms of reference, and practices that extend beyond science into policy,
civil society, media, national government, and international
governance. Controversy becomes about ‘how the certication of
knowledge matters to the resolution of broad social struggles’ [15].
In doing so, we build upon and connect past studies on particular
solar geoengineering or carbon removal experiments [9,17,18], or re-
views within technology types (e.g. [19] on ocean fertilization; [20] on
solar geoengineering), to experiments currently unfolding. We develop
insights relevant to governance outlooks that draw upon prospective
[21], stalled [22], or ongoing experiments [23], and to the emerging
literatures of technological perceptions, discourses, and intents sur-
rounding radical climate experiments and their governance [24–27].
2. Research design
We deploy a qualitative comparative analysis (QCA), treating cases
(e.g. an experiment) as a combination of factors (e.g. issues, actors,
tactics) that contribute to a certain outcome (e.g. opposition and con-
troversy) [28–30]. Following QCA guidance, we generalize modestly,
drawing insights between the technological elds examined as part of
the study [29,31]. In this, we follow recent work conducted on socio-
technical transitions [32].
We draw attention to more unproven prospective interventions, and
concentrate our analysis on carbon removal and solar geoengineering
approaches between TRL 3–5 (see Fig. 1): ocean fertilization, marine
cloud brightening, stratospheric aerosol injection, ice protection, and
Fig. 1. Classifying climate interventions by Technological Readiness Level.
Source: Authors and Benjamin Mitterrutzner, based on qualitative discussions and unpublished data from the International Institute of Applied Systems Analysis as
well as ETH Zurich. These are part of a large European Research Council project, GeoEngineering and NegatIve Emissions pathways in Europe (GENIE).
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
3
enhanced weathering. TRLs are a widely-used framework for system-
atically measuring and managing technologies over different parts of the
journey from invention to maturity [33]. Nine TRLs are often identied
in order to track the status of development progression (below); we
focus on approaches within TRLs 3–5 to highlight contestation during
the development or experimental stages beyond proof-of-concept, but
prior to demonstration.
1. Initial idea: basic principles have been dened
2. Application formulated: concept and application of solution have
been formulated
3. Concept needs validation: solution needs to be prototyped and
applied
4. Early prototype: prototype proven in test conditions
5. Large prototype: components proven in conditions to be deployed
6. Full prototype at scale: prototype proven at scale in conditions to be
deployed
7. Pre-commercial demonstration: solution working in expected
conditions
8. First-of-a-kind commercial: commercial demonstration, full-scale
deployment in nal form
9. Commercial operation in relevant environment: solution is
commercially available, needs evolutionary improvement to stay
competitive
TRLs, used simplistically, can reify techno-economic biases. How-
ever, the framework is increasingly used and expanded as a springboard
to investigate the social dimensions of new or experimental technolo-
gies, especially in the context of climate change mitigation or decar-
bonization [34–36]. With an eye to these extensions, we retain the use of
TRLs for two reasons. Firstly, the TRL framework has been extensively
applied to emerging energy and climate technologies [37–43]. Secondly,
this paper exists as part of a large European Research Council project,
GeoEngineering and NegatIve Emissions pathways in Europe (GENIE),
where the TRL framework is more widely used (see also Fig. 1).
After screening 44 experiments or projects with planned experiments
within these technological clusters undertaken or announced from 1990
to 2020/2021 (Annex 1), we select 21 as in-depth case studies. Our
choice of case studies is guided by several criteria. We focus on (plan-
ned) experiments that have been confronted by visible controversy and
contestation. However, from the vantage point of 2022, we also look at
experiments which raised no signicant controversy at the time, but
with hindsight have become more controversial, have clearly inuenced
the design and contestation of experiments, or continue to embody
interesting dynamics for future experiments.
Our QCA framework of analysis for all cases comprises four elements.
First, we examined the initial experiment design and governance,
highlighting the initial actors (e.g. principle investigators), risks envi-
sioned (e.g. environmental or social implications), and governance
practices intended to explore and mitigate risk (e.g. impact assessment,
stakeholder engagement). Second, we examined (where relevant) the
emergence of controversy and opposition to the experiment: high-
lighting new actors, different risks envisioned (often in contrast to those
emphasized by experiment designers), and oppositional practices
intended to shut down the experiment. Third, we analyzed if and how
experiment designers reacted to controversy, modifying their gover-
nance practices to engage with oppositional concerns – we were inter-
ested in whether new experiment governance took place or was able to
navigate or defuse controversy. Fourth, we concluded with each case's
implications for future assessment and political debate. Where contro-
versy did not occur, we focused on the rst element. It is important to
note that because of space constraints, we cannot detail every case study
according to this four-step framework. Rather, we present our data and
analysis in the following manner.
The following Section 3 describes and analyses the experiments by
technology, creating ve comparative summaries of how these
experiment clusters and social opposition – or lack thereof – have
unfolded over time. These summaries are necessarily abbreviated, but
highlight key motivating issues and tactics of social contestation. Sec-
tion 4 then builds on these summaries by deriving generalizable insights
across all experiments and technologies.
3. Summaries of climate intervention experiments by
technology
In this section, we summarize the ve broad clusters of radical ex-
periments investigated in the paper: ocean fertilization (Section 3.1),
marine cloud brightening (Section 3.2), stratospheric aerosol injection
(Section 3.3), ice protection (Section 3.4), and enhanced weathering
(Section 3.5).
3.1. Ocean fertilization
Ocean fertilization – the release of iron or other nutrients to seed
phytoplankton blooms that sequester carbon – has had the longest run of
experiments and the most varied career in framing of intent. Our QCA
examined four ocean fertilization experiments in depth (Table 1):
Planktos (2007, which we label OF1), Climos (2008–2009, OF2),
Lohafex (2009, OF3), and the Haida Salmon Restoration Corporation
(2012, OF4).
Experimentation represents three overlapping phases. The rst two
phases are summarized by Strong et al. [19]. Beginning in 1993, sci-
entic institutions rst sought to establish the processes of phyto-
plankton's ‘biological pump’. Over the 2000s, ocean fertilization as a
scientic endeavor was paired with a second stream of for-prot en-
terprises that sought to commercialize ocean fertilization though carbon
credits. A smaller number of commercial enterprises were conducting
trials, but with little remaining documentation and of unclear value
[19]. All appeared to pass without concerted opposition, though in a
period of rising debate. Established scientic networks viewed com-
mercial ocean fertilization with wariness, but the debate grew in visi-
bility due to mutual exchange between the two streams [19].
In 2007, Planktos (OF1) – a for-prot enterprise built around
American entrepreneur Russ George – announced a plan to seed an
unprecedented area of 10,000 km
2
near Ecuador's Galapagos Islands
[44]. The prospect of commercially-driven, large-scale ocean fertiliza-
tion was made more pressing by George's reputation as a maverick
Table 1
Ocean fertilization case studies.
Case
abbreviation
Full name of
experiment or
project (if
applicable)
Project leads or host Year and
location
OF1 Planktos II (a prior
experiment,
Planktos I, had
taken place in
2003)
Planktos, led by Russ
George
2007; Near the
Galapagos
Islands
OF2 Climos Climos, led by Dan
Whaley and Margaret
Leinen
Planned for
2008–2009, but
not conducted.
OF3 Lohafex Alfred Wegener
Institute, Germany, led
by Victor Smetacek, and
CSIR-National Institute
of Oceanography, India,
led by Syed Wajih Naqvi
2009; Southern
Ocean
OF4 Haida Salmon
Restoration
Corporation
Haida Salmon
Restoration
Corporation, led by Russ
George and John
Disney; founded by the
Old Massett Village
Council of Haida Gwaii
2012;
Northwest
Pacic Ocean
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
4
within both scientic and entrepreneurial circles – he sold his own
carbon offsets, and openly celebrated his efforts as pushing ‘useful ocean
research [beyond] the exclusive domain of the richest researchers’ [45].
Planktos' plans catalyzed widespread scientic and ENGO protest
[46,47] that would lead to the experiment's premature cancellation
[19]. The efforts contributed to the emergence of an evolving ENGO
network who would continue to protest ocean fertilization as local socio-
ecological disruption as well as a slippery slope to large-scale marine
geoengineering, whose members would become active in experiments
beyond ocean fertilization. In turn, protests spurred the Convention on
Biological Diversity (CBD) and London Convention and Protocol (LC/
LP) to develop guidelines on ocean fertilization experimentation and
‘marine geoengineering’ – which have also come to inuence experi-
ments and their opposition within and beyond ocean fertilization [19].
Climos (OF2), a concurrent for-prot enterprise, also had experi-
ments planned – but these were never carried out in the aftermath of the
Planktos episode [19]. Nevertheless, Climos is signicant for posing a
different operations model: aiming to integrate the practices of estab-
lished scientic, business, and policy networks. Climos established a
Code of Conduct emphasizing marine protection, rigorous credit ac-
counting, and transparency [48], alongside publications exploring
science-business relations [49], and developed carbon credits [50]
intended to meet demands for third party verication, additionality, and
100-yr permanence. Climos' efforts did not prove sufcient to overcome
ENGO opposition and scientic mistrust [51]. It closed in 2011, citing
‘the failure of governments to maintain economic signals that can sup-
port market-based solutions’ [52].
The 2009 Lohafex experiment (OF3) was the point at which ocean
fertilization became scientically challenged and commercial interest
began to ebb. A project that has come to be seen as the capstone of
around 12 experiments conducted by established scientic networks
between 1993 and 2005 (Annex 1; summaries can be also found in
[19,53]), Lohafex found that when taking a wider web of marine ecology
into account, most carbon was only temporarily sequestered [54].
Project communications, attuned to political and commercial contexts,
expressed clear doubt on ocean fertilization's sequestration potential
[55] – a conclusion ensuring that commercial activities could not endure
[19].
But Lohafex also had ripple effects in experimental governance, as a
high-prole case of science diplomacy between Germany and India [56].
Oppositional ENGOs leveraged this visibility, targeting the experiment
with a solidifying strategy: challenging a ‘host’ country's reputation
(here, Germany as host to the Alfred Wegener Institute, a principal
institution) based on violation of international guidelines in the making
since Planktos' 2007 activities. In turn, this challenge exposed deni-
tional politics over ‘legitimate research’, scale, and location, which
differed between the Convention on Biological Diversity and the London
Convention and Protocol [56]. The overseeing German ministries agreed
to momentarily halt Lohafex, while seeking several independent rulings
on its environmental impact and international legal guidelines. In de-
fense, Lohafex's team framed the experiment within the Convention on
Biological Diversity's strictures [57], and further defended the experi-
ment via institutional communications and appeals to a politically-
neutral, scientic ethos. The project's press releases emphasized scien-
tic grounding, separation from commercial and political intent, willing
compliance with the independent assessment, and that Germany's
credibility in international science and environmental governance
remained unsullied [54,58,59]. The independent rulings found in the
experiment's favor [57], and weeks later, the resumed experiment had
acquired its data.
Yet, both scientic and commercial efforts continued in a dampened
third phase of activity that extends into the present. The benchmark
example was the Haida Salmon Restoration Corporation or HSRC (OF4),
led once again by Russ George. The indigenous Haida of Canada's Pacic
coast were then faced with decreasing salmon runs (a cultural and
economic mainstay), and George helped convince one of their
communities to borrow $2.5 million (CAD) to found the HSRC, which
would deploy ocean fertilization to seed phytoplankton blooms and in-
crease salmon stocks. Meanwhile, George (incorrectly) promised that
the carbon sequestered could be sold via carbon credits, recouping the
initial investment [17,60]. HSRC scaffolded the experiment's design and
governance with Haida mythology, socio-economic policies around
ecosystems restoration and services, and community governance
[60,61]. The loan was approved by a community vote, and the local
Village Council approved three research permits [17]. In the summer of
2012, the experiment was conducted in international waters, 400 km
west of Haida Gwaii.
It was only retroactively that the ETC Group and allied ENGOs
contacted news media to describe the event as a violation of interna-
tional guidelines [17]. Researchers in a parallel debate on solar geo-
engineering experimentation, themselves ghting for legitimacy (SAI3),
denounced HSRC's ‘rogue science’ [17]. Scientic commentators recal-
led Planktos, arguing that George had duped an indigenous community
with the promise of carbon credits [61,62]. Haida communities and
authorities were taken by surprise, with the episode exposing fear of
connection to geoengineering, and re-opening questioning about the
project's relative prioritization of salmon restoration or carbon credits,
cultural appropriation of Haida stewardship, and jurisdictions between
Haida authorities [17,60,61]. In 2013, the Haida removed George from
his position [63], and the HSRC was dissolved. Still, the episode raised
uneasy questions about the convergence between non-traditional
research, and indigenous and local knowledge – George's brand of ‘cit-
izen science’ was easy to deride as ‘rogue science’, but it was more
fraught to dismiss the experiment's co-development with Haida culture,
economy, and self-government [17,60,61]. Moreover, ocean fertiliza-
tion experiments and ‘marine’ geoengineering were connected via a
wider framing of ‘climate’ geoengineering to planned experiments on
solar geoengineering, entrenching further discussion on the unclear
legal ‘patchwork’ surrounding small-scale research.
HSRC also ushered in a new phase for framing ocean fertilization.
Non-established scientic and entrepreneurial networks continue in a
small cluster of initiatives. Oceanos (a research organization) and the
Ocean Nourishment Corporation (a private company) explicitly reject
geoengineering and give light treatment to carbon removal and carbon
crediting, while emphasizing local developmental co-benets through
‘ocean seeding’ [64], ‘nourishment’, and ‘restoration’ [65]. Both claim
frameworks for designing, conducting, and governing eld trials [66], of
which no documentation exists. The Ocean Nourishment Corporation
has applied for patents in aspects of the ocean fertilization process [67].
There is a lingering implication of commercialization-by-stealth [68].
This, in turn, reects two trends. Hybrid initiatives marrying entrepre-
neurial and technical innovation are expanding across (marine) carbon
removal development and eld-work [69], from the Ocean Visions
Alliance, to more technology-specic Running Tide (macro-algae
sequestration) and Project Vesta (enhanced weathering, EWO2), and
even marine cloud brightening (MCB2). Some of these efforts lean into
being labelled as nature-based, local ecosystems restoration and man-
agement, and possessing co-benets for local actors or industry.
Meanwhile, scientic efforts may be reviving – Cambridge's Sir
David King is proposing a new method for ocean fertilization, with ex-
periments planned for 2022 [70]. The London Convention and Protocol,
through its advisory body, also continues to map new marine geo-
engineering approaches and to deliberate on experimentation bounds
[18,71].
3.2. Marine cloud brightening
Marine cloud brightening (MCB) posits that clouds can be seeded
with salt particles (via spraying seawater), reecting sunlight over
vulnerable locales [72]. It has risen to greater prominence through the
climate geoengineering debate, as part of solar geoengineering [1] - but
had been considered in scientic circles as early as ocean fertilization
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
5
[73]. Marine cloud brightening builds on an analogous anthropogenic
activity: in this case, sunlight-reecting ‘ship tracks’ created by the
particulate matter emitted as part of shipping pollution.
Our QCA considered three MCB experiments (Table 2): E-PEACE
(2011, which we labelled MCB1), the MCB Project (ongoing, MCB2), and
the Great Barrier Reef project (ongoing, MCB3). Indeed, the physics of
clouds are subject to many uncertainties. As such, MCB is viewed as a
more uncertain and regional kind of solar geoengineering, compared to
the planetary schemes posed by stratospheric aerosol injections (SAI)
(see Section 3.3). It has received far less study in earth system modelling
and in political risk assessment. However, it still commands attention -
featuring both in landmark reports from the US National Academies
[5,74], as well as the London Convention and Protocol scientic advi-
sory body examining ‘marine geoengineering’ [71].
E-PEACE (MCB1) investigators did not initially describe the project
as a eld demonstration for marine cloud brightening or geo-
engineering, and it is unclear if they envisaged it as such. Rather, the
project was described as atmospheric science, referencing work on
cloud-aerosol interactions [75]. Unengaged by ENGO opponents, E-
PEACE was completed in July 2011, off the coast of Monterrey, Cali-
fornia. But afterward, scientists engaged in solar geoengineering
research pointed out that E-PEACE researchers had (deliberately or
implicitly) avoided ENGO opposition and more stringent governance
because they did not explicitly connect the experiment with geo-
engineering [20]. Indeed, with no physical difference at small scales
between basic science (cloud-aerosol interactions) and precursor stages
of geoengineering, scientists could self-label as either or both – and it
was not clear which choice could avoid or invite controversy. However,
demands for E-PEACE's transparency of intent had different motives.
Some observers severely mistrusted the potentials of solar geo-
engineering while others sought to conduct their own experiments [20]
– mirroring intra-scientic conversations in ocean fertilization. E-
PEACE's investigators acknowledged implications for marine cloud
brightening and geoengineering thereafter [76,77].
The more recent Marine Cloud Brightening Project or MCBP (MCB2),
unlike E-PEACE, explicitly references solar geoengineering and climate
geoengineering [78–80]. Originally called The Silver Lining Project, it
branched in two parts. The rst is the MCBP, a formalized scientic
project led at the University of Washington [78]. The second - and
MCBP's partner in policy support and communications - is the NGO
Silver Lining. Silver Lining is an advocacy organization for solar geo-
engineering built around Kelly Wanser (a former Silicon Valley execu-
tive), which has become signicant for its innovation- and philanthropy-
facing activities, a polished public prole (comparable with Project
Vesta, EWO2), and for controlling the funding that supports a great deal
of solar geoengineering modelling research [81]. MCBP has meanwhile
maintained a three-stage plan for experimentation [82], but even its
most preliminary phase remains suspended due to insufcient funding.
Opposing ENGOs have nevertheless mentioned MCBP in the context of
an experiment that has more recently gone ahead [83].
The Marine Cloud Brightening for the Great Barrier Reef or MCB-GBR
1
project (MCB3), like E-PEACE, is signicant for having been completed
its rst phase (in 2020, off the Queensland coast of Australia) while
avoiding ENGO opposition, and making no allusions to climate geo-
engineering. But there, the comparisons end. The stated objective has
rather been to investigate MCB's capacity to forestall coral bleaching of
the Great Barrier Reef as a measure for ecosystems protection and re-
covery, and as part of a larger system of such efforts [84–86]. Unlike E-
PEACE, the Australian experiment's governance relied on more than
academic procedures – principal investigators complied with all do-
mestic environmental laws [18], and acquired the consent of the area's
indigenous custodian [84].
More signicantly, MCB-GBR has incorporated into the $150 m
(AUD) funded Reef Restoration and Adaptation Program (RRAP) [84].
RRAP - an ambitious partnership between the Australian government,
CSIRO (Australia's national research agency), the Great Barrier Reef
Marine Park Authority, and several marine institutes and universities -
investigates a system of interventions that would shade, stabilize, and
seed coral reefs [23,87], representing the emergence of a discourse
regarding such interventions as restoration and resilience of (iconic)
ecosystems, alongside benets for science, and time-buying for “viable
long term solutions” [18,85]. Future trials [84,88], alongside regulatory
assessments and stakeholder engagements [89], are being planned over
the next 10 years.
Belatedly, ENGOs led by the ETC Group responded with references to
geoengineering and violation of international guidelines [83]. But the
main controversy was intra-scientic. E-PEACE (MCB1) was invoked –
that researchers could avoid scrutiny by steering clear of contentious
framings around solar geoengineering [90]. Moreover, the project
highlighted another dimension of jurisdictional issues. Many tests have
raised demand for novel governance mechanisms or referenced inter-
national guidelines. MCB-GBR, however, would operate within national
territory with legal and governmental consent [18], raising the question
if different domestic contexts might provide clearer or murkier gover-
nance landscapes.
3.3. Stratospheric aerosol injection
The most commonly proposed deployment scheme for stratospheric
aerosol injection (SAI) proposes to maintain a layer of reective parti-
cles in the upper atmosphere with modied aircraft [91]. Our QCA
covers three projects (Table 3): Yuri Izrael's eld experiment (2008,
SAI1), SPICE (2012, SAI2), and SCoPEx (2021, SAI3). Unlike marine
cloud brightening, since reective particles would spread across the
upper atmosphere, SAI's cooling effects would be planetary in scope - but
depending on the dimensions and location of deployment, with uneven
regional effects [92]. Stratospheric aerosol injection is thought to
possess low implementation costs coupled with high leverage on global
temperatures, as well as the largest uncertainties in geopolitics and
public consent [93]. As a result, stratospheric aerosol injection is
sometimes viewed as having the clearest links to the concept and
inchoate risks of geoengineering. The most attention in assessment has
been devoted to this approach [5,74,92], and the most scientic and
ENGO opposition as well [94,95].
These associations have extended into the planning of and opposition
to stratospheric aerosol injection experiments - which, regardless of
initial small scale and ‘exit ramps’ posed (e.g. [74]), connect to the end-
Table 2
Marine cloud brightening case studies.
Case
abbreviation
Full name of
experiment or
project (if
applicable)
Project leads or host Year and
location
MCB1 E-PEACE - Eastern
Pacic Emitted
Aerosol Cloud
Experiment
University of California
San Diego, led by Lynn
Russell
2011;
Monterrey,
California, USA
MCB2 Marine Cloud
Brightening
Project
University of
Washington, led by
Robert Wood and Tom
Ackerman (part of a
wider consortium)
Delayed since
2018;
Monterrey,
California, USA
MCB3 Marine Cloud
Brightening for the
Great Barrier Reef
Southern Cross
University, led by
Daniel Harrison (now
part of the Reef
Restoration and
Adaptation
Programme)
2020; Great
Barrier Reef,
Australia
1
The project does not appear to have been given an acronym by its scientic
investigators.
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
6
vision of a high-leverage planetary sunshade [27,96]. This has also made
the approach more difcult to describe in ‘natural’ or ‘local’ terms
sometimes deployed in carbon removal or marine cloud brightening
conversations.
2
These factors ensure that stratospheric aerosol injection
experimentation has operated in the least permissive environment in
terms of ENGO and scientic attention.
In 2009, Russian scientists published a paper claiming the rst out-
door study (SAI1) of stratospheric aerosol injection [97], which had
passed without visible notice from ENGOs. This small-scale test (sul-
phate aerosols injected at 50 m and 200 m from a pair of army vehicles)
was led by (the now late) Yuri Izrael – a scientist of high standing in the
IPCC, who nevertheless questioned anthropogenic climate change and
lobbied Putin to consider solar geoengineering [20]. Izrael's experi-
ment's deliberate association with solar geoengineering was unprece-
dented in 2008. However, researchers into stratospheric aerosol
injection outside of Russia swiftly disassociated themselves, delegiti-
mizing it as a contribution to legitimate scientic inquiry – where it
remains only sporadically mentioned as a cautionary tale in political
studies [20,98]. Izrael's experiment also serves as an early ‘dark mirror’
of the scenario posed more recently by Australian marine cloud
brightening trials (MCB3): an experiment held within national juris-
diction, and with (tacit) support of government authorities. This made
the Russian test concerning to external observers, where intransparency
and the overt geoengineering connection became easy to conate with
projections of the Russian state's geopolitical goals [20].
The 2012 UK-based SPICE ‘test-bed’ (SAI2) occurred during a period
of charged debate over both carbon removal and solar geoengineering
(E-PEACE, MCB1 and HSRC, OF4 also took place during this time). The
test has an uncommon legacy: its failure to be conducted is sometimes
recalled as a success for its governance. Part of a wider-ranging research
consortium, the test-bed proposed to test the mechanics of an eventual
delivery system via a small-scale version: an 18 m long balloon spraying
water 1 km in the air. The progress of the test-bed was coupled to a
comparatively extensive governance framework: a ‘stage gate’ review.
SPICE investigators would have to pass ve technical and societal
criteria for the test-bed to proceed, judged by a multidisciplinary panel
[22,101]. SPICE personnel conducted a multi-dimensional assessment,
an environmental impact assessment, and stakeholder engagements.
Some in the team welcomed the process as a needed grappling with
normative and political implications of science; others implied that it
could feel tedious or unnecessary [20,22]. But project leaders called the
test off before it was fully vetted by the stage gate panel. ENGOs led by
the ETC Group take credit, having driven negative public and media
attention [102], including a letter to the UK government claiming
violation of international guidelines [103]. The SPICE team maintain
that they had suspended the test of their own accord, due to a late dis-
covery that project personnel had applied for a patent on a component of
the delivery mechanism, raising a conict of interest [104,105].
SPICE's most interesting implication is posed by the test-bed's
governance. Technology governance practitioners used SPICE as the
foundational case in developing the ‘responsible research and innova-
tion (RRI)’ framework [22], which has since been widely referenced in
solar geoengineering and carbon removal [106]. In this sense, the real
trial was not of the delivery system, or even of stratospheric aerosol
injection experimentation - but of RRI as a framework for societal
appraisal. RRI practitioners recall the cancellation as a healthy reection
of principles surfaced by the stage-gate [9,107]. But it is less clear
whether the bulk of technical researchers in solar geoengineering
consider the RRI framework help or hindrance [106].
Debate over the proper shape of experimental governance and so-
cietal appraisal have carried over into SCoPEx (SAI3) – a test long
contested by ENGOs [108] as inextricable from David Keith, a leading
scientic gure and vocal advocate in solar geoengineering [2,109]. As
part of a nalized project plan that has seen many iterations, the
experiment (a ‘platform test’ of a small-scale delivery mechanism, with
no material release) was to take place in Kiruna, northern Sweden, in the
traditional lands of the indigenous Saami. SCoPEx investigators saw the
risks as technical and environmental, both argued to be negligible [110].
The contrast with the society-facing orientation of SPICE's governance
(SAI2) is clear. Still, SCoPEx sought to provide a (alternative) template
for experimental governance [111], instigating the formation of an in-
dependent Advisory Committee, which in turn initiated a series of legal,
engineering, nancial and societal reviews that would precede the test.
As part of the reviews, the Advisory Committee recommended societal
engagements that the project team contested as too restrictive.
3
Before the experiment (or engagements of any scope) took place,
controversy emerged. In February 2021, a rst letter was sent to the
Swedish ministries for environment, research, and enterprise and the
Swedish Space Corporation by domestic and international ENGOs
(including the ETC Group). This letter challenged Sweden's commit-
ments in light of the incoming Stockholm +50 Conference in 2022, and
referenced violation of international guidelines, geoengineering, and the
UN Declaration on Rights of Indigenous Peoples [112]. A second open
letter was sent to the SCoPEx Advisory Committee from the Saami
Council, stressing that a small-scale test ‘cannot be treated in isolation to
ScoPEx's overall intentions’ towards solar geoengineering [114]. Besides
this global element, the letter invoked local concern: no agreements had
been sought or reached with Saami and Swedish governments or societal
groups. The SCoPex team agreed to suspend the test, and later
announced that it was ‘working with science engagement specialists in
Sweden and seeking a host for engagement’ [115]. The Advisory Com-
mittee also released a call for new members, emphasizing diversity and
marginalized communities, and with language targeted towards (what
they may see as) disruptive ENGO tactics [116]. The Saami Council has
maintained its opposition, beginning a petition in June 2021 to shut the
project down [117].
Comparison between SCoPEx and the SPICE stage-gate (SAI2) is
unavoidable. The SCoPEx team favored clearer physical and technical
thresholds for safe experimentation, and a focus on local dimensions in
stakeholder engagement; the SPICE team engaged with uncertain soci-
etal prospections due to the demands of their stage-gate panel. As it
Table 3
Stratospheric aerosol injection case studies.
Case
abbreviation
Full name of
experiment or project
(if applicable)
Project leads or host Year and
location
SAI1 Yuri Izrael's Field
Experiment on
Studying Solar
Radiation Passing
through Aerosol Layers
Roshydromet and
Russian Academy of
Sciences, led by Yuri
Izrael
2008;
Saratov,
Russia
SAI2 SPICE ‘Test bed’-
Stratospheric Particle
Injection for Climate
Engineering
Bristol University, led
by Matthew Watson
(part of a wider
consortium)
Suspended
2012;
Norwich, UK
SAI3 SCoPEx - Stratospheric
Controlled Perturbation
Experiment
Harvard University,
led by Frank Keutsch
and David Keith
Suspended
2021; Kiruna,
Sweden
2
This is not to say that such efforts do not exist. Corner et al. [99] notes
efforts connecting stratospheric aerosol injection with ‘natural’ phenomena (e.
g. volcanoes). Optimized modelling work also contains efforts to demonstrate
regional variation and tailoring, which are critiqued in McLaren [100].
3
The SCoPEx team saw the Advisory Committee's recommendations - calling
for comprehensively engaging with the future implications of SCoPEx for wider
politics - as restrictive and vague (again, recall the stage gate of SPICE, SAI2). A
middle ground was found, calling for citizen engagements in the area of
operation, solicited by an independent engagement group, on two aspects: local
concerns, and ideal research governance (SCoPEx Advisory Committee [113]).
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
7
turned out, the SPICE panel had a point: it is not the (negligible and
localized) physical risks that continues to concern opponents of small-
scale tests, but “a slippery slope towards normalization and deploy-
ment” [112].
3.4. Ice protection
Ice protection is gaining more attention due to growing appreciation
of the collapse of glaciers and ice sheets - ranging from the relatively
small and local scale, e.g., in mountain ranges such as the Alps, to the
continental scale in Antarctica and Greenland. Our QCA captures one
case (Table 4): the Arctic Ice project (IP1).
We note that high-TRL glacier cover systems already encompass
diverse efforts to mimic the reectivity of snow and protect glaciers from
melting [118–120]. Funding comes from commercial sources such as ski
resorts, which means they tend to be clustered in high-prestige locations
such as the Alps. Representing a low-tech, low-cost – if not low-effort –
solution, such systems employ rolled-out ‘geotextile tarpaulins’ that
reect sunlight [118]. These lo-, localized solutions do not necessarily
demand or benet from further research, and have not yet been treated
as controversial forms of climate intervention. For now, they represent
cases of (partly) commercially motivated and funded protection of
glacier ecosystems with recreational and touristic interest.
The Arctic Ice Project (IP1) represents a more immature technology –
developing ‘hollow glass microspheres as a means for small, controlled
and localized … surface albedo modication’ [121]. The project has
been conducting or planning eld experiments in Alaska (USA), Min-
nesota (USA), Manitoba (Canada), and Svalbard (Norway) [122]. The
work in the USA has been well underway since 2017 [123]. But COVID-
19 severely curtailed the expansion of eld research to Manitoba and
Norway, and there are few updates on progress [124]. But beyond a
limited brieng from Geoengineering Monitor [123], critical ENGOs
have not engaged.
Moreover, the project reects more recent trends in framing: it
explicitly rejects geoengineering, preferring ‘climate intervention’ as
‘action intended to improve the climate situation’ [121]. In doing so, it
frames ‘ice restoration’ as part of wider innovations into ‘climate
restoration’, that might ‘buy up to fteen more years for our global
economies to decarbonize’ and offers ‘a credible and timely path to
signicantly reduce climate-related losses’ [121]. The project also
avoids the impression of non-establishment science - emphasizing col-
laborations with Canadian and Norwegian scientic institutions. At the
same time, the project is reliant upon philanthropy, and appeals to
innovation-focused actors through a vision to ‘continually develop the
technology funnel for improved methods of ice restoration’ [122,124].
While current efforts at glacier protection are not seen to be problematic,
forthcoming efforts at a larger scale could land them more rmly on the
radar of ENGOs.
3.5. Enhanced weathering
Enhanced weathering strives to accelerate natural processes of
weathering, wherein calcium- and magnesium-rich silicate rocks (e.g.
basalt and lime) bind and remove CO2 in the atmosphere as they break
down over time. Enhanced weathering is becoming more prominent for
its stated potential to store carbon, at a relatively low cost, on the
magnitude of 2.9 to 8.5 billion tonnes per year by 2100 [125–131].
Despite featuring in landmark reports [4], signicant uncertainty re-
mains on the effectiveness and permanence of sequestration, given the
lack of eld-scale evidence.
Our QCA captured ten experiments (Table 5), categorized in
following sub-sections by spatial application: terrestrial environments
such as croplands and rangelands (the Guelph wollastonite trials, EWT1;
LC3M, EWT2; Working Lands Innovation Center, EWT3; and Project
Carbdown, EWT4), coastal and marine environments (One Tree Reef,
EWO1; Project Vesta, EWO2; OceanNETs, EWO3; and GGREW, EWO4),
and the mining sector (FPX Nickel Corporation trials, EWM1; and Car-
bonVault™, EWM2).
In comparison to other technological clusters, very few enhanced
weathering initiatives have been subject to visible, high-prole critique.
Field trials center on the prominent rationale of co-benets for regional
ecosystems, agriculture, or industry, and how this may motivate
acceptance and adoption among relevant stakeholders. But attention to
governance and public acceptance varies signicantly. The majority of
Table 4
Ice protection case studies.
Case
abbreviation
Full name of
experiment or
project (if
applicable)
Project leads or
host
Year and location
IP1 Arctic Ice Project
(formerly Ice911
Research)
Arctic Ice
Project, led by
Tom Light and
Leslie Field
Since 2017 in Alaska and
Minnesota, USA;
planned for Manitoba,
Canada and Svalbard,
Norway
Table 5
Enhanced weathering case studies.
Case
abbreviation
Full name of
experiment or
project (if
applicable)
Project leads or host Year and location
EWT1 Guelph
wollastonite trials
Guelph University,
led by Yi Wai Chiang
and Rafael M. Santos
2015–2018 (and
ongoing); southern
Ontario, Canada
EWT2 Leverhulme
Centre for Climate
Change Mitigation
(LC3M)
Leverhulme Centre
for Climate Change
Mitigation,
University of
Shefeld
Since 2018; Illinois,
United States, north
Queensland,
Australia and
Malaysian Borneo
EWT3 Working Lands
Innovation Center
Working Lands
Innovation Center,
UC Davis (with
Cornell College of
Agriculture and Life
Sciences), led by
Benjamin Houlton
and Whendee Silver
Since 2019;
multiple sites
across California
and one site in New
York
EWT4 Project CarbDown Project CarbDown Since 2020; across
EU (i.e. Greece,
Germany,
Netherlands)
EWO1 One Tree Reef Carnegie Institution
for Science, led by
Ken Caldeira
2014; Great Barrier
Reef, Australia
EWO2 Project Vesta Project Vesta Underway after
being delayed to
late 2021;
undisclosed coves
in the Caribbean
EWO3 OceanNETs GEOMAR Helmholtz
Centre for Ocean
Research Kiel, led by
Judith Meyer and
David Keller
Underway since
2021; Canary
Islands
EWO4 GGREW University of Oxford,
Cardiff University,
University of
Southampton,
University of
Cambridge
Suspended in 2020
(due to COVID);
Gulf of Eliat, Israel
and Great Barrier
Reef, Australia
EWM1 FPX Nickel
Corporation
FPX Nickel
Corporation
Since 2019; Decar
Nickel District and
Vancouver, Canada
EWM2 CarbonVault™ De Beers Group Since 2020; Venetia
mine in South
Africa and Gaucho
Ku´
e in Canada
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Energy Research & Social Science 90 (2022) 102594
8
trials are positioned as scientic or technical processes, and lack of
public outreach and engagement could in the future create space for
criticisms on the harmful impacts on (poor) communities and local en-
vironments, high energy and water usage, or to generally label such
efforts as greenwashing or camouage [132–135]. Other trials display
concerted and early attempts at stakeholder outreach (EWT3, EWO3),
while others contain explicit orientation towards innovation-based,
commercial actors and demands for funding and technical support
(EWT4, EWO2).
3.5.1. Terrestrial enhanced weathering
Running from 2015 to 2018, the Guelph wollastonite trials (EWT1)
were undertaken by agricultural scientists at the University of Guelph in
partnership with the mining operation Canadian Wollastonite, to
develop a large-scale carbon-sequestering option for regional farmers
and fertilizer producers [136,137]. Despite being the only large-scale
commercial eld trials completed to date, the Guelph trials do not
refer to enhanced weathering or geoengineering, but to agronomic
research, novel ways to support farming business models, and new
partnerships with regional industries and rural communities. Gover-
nance and public acceptability of the trials themselves are not empha-
sized – rather, the pitch of local co-benets is central.
By contrast, the Leverhulme Centre for Climate Change Mitigation
(LC3M; EWT2) explicitly orients itself towards the ‘grand challenge’ of
climate change mitigation, with enhanced weathering in agricultural
soils framed as a ‘strategic ‘negative emissions technology” and ‘climate
geoengineering method under natural conditions’ [138]. Ongoing since
2018, LC3M assumes the mantle of the rst high-prole project on
enhanced weathering in the world [131]. LC3M's trials are conducted in
three agricultural ecosystems: sugarcane plantations in Queensland,
Australia (James Cook University, 2020); palm oil plantations in Borneo,
Malaysia; and a large mixed-crop agro-ecosystem in Illinois, United
States [139]. Local partners have been integrated into trials. Couplings
to agriculture and local economies are prominent, with envisioned co-
benets in higher production yields, crop protection from pests and
diseases, less need for expensive fertilizers and pesticides, and improved
water quality. LC3M understands risks as agricultural and environ-
mental impacts, e.g., management of toxic leaching from mine tailings.
There is an implicit market-based governance approach, with relevant
actors informed of potential risks and action taken to ensure that supply
chains are well-managed. Conversely, LC3M has stressed public
engagement, undertaken within a separate project strand by researchers
from the social sciences – key concerns identied include development
of enhanced weathering taking too long to be a solution to climate
change, potential effects on ocean ecologies, and the failure to address
the root cause of climate change [134,135]. At present, however, LC3M
has generated little explicit controversy.
The Working Lands Innovation Center (WLIC; EWT3) has been con-
ducting experiments in California since 2019 and New York since 2021
[140]. The trials combine enhanced weathering, biochar, and organic
compost ‘in real live settings across a variety of cropping systems (corn,
alfalfa, tomatoes, almonds), rangelands (coastal and interior), soils, and
climates’ [140–142]. Benjamin Houlton, the project leader, promotes
WLIC as ‘the largest enhanced weathering demonstration experiment on
real farms in the world’ [143]. Similar to other terrestrial enhanced
weathering trials, WLIC emphasizes the potential for agronomic and
agricultural co-benets. Wedded to these, however, is an atypically
earlier focus on public, policy, and stakeholder outreach: an ‘Enhanced
weathering protocol’ as a template for researchers and practitioners, as
well as plans to conduct cost-benet analysis, commercialization as-
sessments, and farmer surveys to explore possible barriers
[142,144,145]. WLIC presents itself as a ‘multi-stakeholder consortium’
with researchers, state agencies, the mining and timber industry,
farmers and ranchers, agricultural extension services, small business
development, and indigenous communities [146,147]. In addition to
one trial being conducted on agricultural lands belonging to the Pauma
Band of Luise˜
no Indians, the project asked the Intertribal Agriculture
Council to review the WLIC proposal early on and has emphasized its
aims of integrating traditional ecological knowledge and engaging
‘communities that had not previously been engaged in this type of work’
[145]. For now, WLIC is under the radar of the public and ENGOs, with
no comments or criticisms identied.
Project Carbdown (EWT4) is the only terrestrial EW project in con-
tinental Europe, with trials underway in Germany, Greece, and the
Netherlands [148–150]. Similar to LC3M (EWT2), effectiveness is trialed
with different mixtures of rock dust (sometimes paired with biochar, as
in EWT3) and variation across ecosystems, local farming practices, and
with an eye towards attaining co-benets. Selling of carbon credits is a
comparatively prominent objective of Project Carbdown – resulting in
university-industry partnerships for improving monitoring capabilities,
such as with the investment rm Carbon Drawdown Initiative, the IT
infrastructure-monitoring rm Paessler AG, and eld-service manage-
ment software rm Fieldcode. As a result, a ‘smart monitoring concept’
that can be employed in elds, along with a small, low-cost ‘Sugar Cone
Device’ claimed to enable real-time monitoring of carbon removal, are
proposed as stand-ins for governance in a more traditional sense.
3.5.2. Ocean and marine-based enhanced weathering
In marine environments, there is a strong overlap with ocean alka-
linity enhancement (for consistency, this paper's case-study abbrevia-
tions use ‘EWO’ for ‘enhanced weathering, ocean’), where mining-
sourced materials are added to oceans or on beaches, leaving the me-
chanical action of waves to (further) facilitate weathering processes
[151–156]. Accordingly, we treat these approaches as a sub-set of
enhanced weathering that differs primarily in locale.
In 2014, One Tree Reef (EWO1) was the rst experiment to isolate the
effect of acidication in a natural reef environment, taking place on the
eponymous atoll in the Great Barrier Reef. Though illustrating how
ocean alkalinization could alter seawater chemistry and counteract
ocean acidication, such activities were neither envisioned nor subse-
quently described as ‘geoengineering’, but rather as basic science
interested in understanding CO2 emission impacts on coral reefs. As
such, this research attracted little attention from opponents of (marine)
geoengineering – as with E-PEACE (SAI1) and early ocean-fertilization
experiments. Key actors included researchers from the United States
and Israel while, notably, the participation of Ken Caldeira and Katha-
rine L. Ricke suggests cross-fertilization with other geoengineering
research.
Project Vesta (EWO2) is one of the most high-prole projects within
coastal or marine environments [157,158], intended to examine the
carbon-sequestration potential of olivine-rich rocks added to a beach
ecosystem. Crucially, Project Vesta sees itself at the vanguard of coastal
enhanced weathering and as an innovation and governance blueprint for
future projects – similar to WLIC (EWT3) for terrestrial activities. Co-
benets like beach nourishment and coastal development are high-
lighted alongside climate mitigation; activities ostensibly assume a
multi-faceted understanding of risk as environmental, health-related,
technical, and logistical, and with governance evolving according to a
multi-stage ‘project roadmap’. Project Vesta's set-up moreover trumpets
an ‘open source’ approach, whereby any scientist in the eld can
contribute to the experimental design and analysis, with all data and
methods promised to be made freely available.
Unlike other EW initiatives, Project Vesta is a non-prot, founded ‘on
Earth Day’ in 2019 by San Francisco-based think tank Climitigation. Its
ethos and approach reects a geographic proximity to Silicon Valley,
devoting substantial attention to self-promotion aimed at the public and
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
9
innovation-oriented funders. Its homepage [160] sets slogans such as
‘Wave goodbye to excess CO2’ and ‘Nature, accelerated’ against glossy
natural landscapes. Partnerships and strategic investments are central,
with Project Vesta representing one of the rst ‘high potential’ projects
on carbon removal (pre)purchased by the online-payments platform
Stripe [161], along with funding from Carbon Drawdown Initiative
(who also provide support for Project Carbdown, [162]), Additional
Ventures [163], and crowdfunding.
Unusually for an enhanced-weathering project, Project Vesta has
been criticized by scientists and ENGOs, notably as a ‘geohack’ [157]
that may have an adverse impact on ocean ecologies and does not
necessarily address the root issue of climate change. Geoengineering
Monitor [132] also opted to highlight the involvement of Eric Matzner,
co-founder of Project Vesta and self-described ‘biohacker’ and ‘brain
entrepreneur’. Furthermore, the media and other researchers have
raised concerns regarding Project Vesta ‘overselling the potential or
discounting the difculties of its approach’ [158]. In response, Executive
Director Tom Green suggested the project aimed ‘to ll in some of the
scientic blanks and demonstrate it can be done for $10 a ton’ [158].
Project Vesta's ostensible reaction to criticism is to promote the potential
of enhanced weathering as a low-cost climate solution (with trials
framed as scientic research) against the threat of climate change, while
also obviating the need to consider other risks and concerns or to un-
dertake stakeholder outreach as projects such as OceanNETs (EWO3)
have done.
OceanNETs (EWO3) is an ocean-centered research project that
launched its experiment off of the Canary Islands in late 2021. With
Project Vesta (EWO2), OceanNETs represents the rst wave of eld trials
in ocean-based enhanced weathering. The distinguishing characteristic
of OceanNETs, among enhanced weathering trials, is its approach to
stakeholder outreach and public engagement. Promoting its use of a
transdisciplinary approach focusing on economic, political, legal, and
social issues, it emphasizes a need for ‘tight dialogue with stakeholders’
and engaging in ‘two-way communication’ [164–166]. It remains to be
seen whether this approach proves useful, but use of diverse techniques
to integrate the perspectives of stakeholders and the public – cross-
country surveys, interviews, lab experiments, and deliberative work-
shops in the Canary Islands and Norway – is a notable innovation. With
regard to risks, explicit reference is made to issues of social and political
acceptance, affordability, and societal impacts (e.g., food security,
human safety), to be coupled with a comparative assessment provided to
society and policymakers.
The Greenhouse Gas Removal by Enhanced Weathering (GGREW)
project (EWO4), led by a multi-university UK consortium, aimed to
assess biological responses to enhanced weathering and to explore its
technological, economic, environmental, and social feasibility in marine
and terrestrial environments [167,168]. Planned activities would have
included a rst-ever eld trial in a ‘controlled reef environment’ (off-
shore in Australia and Israel) and to assess the viability of enhanced
weathering with mining waste materials (in South Africa). In the end,
eld trials were downgraded to laboratory experiments in Oxford and
Israel. Still, GGREW attracted scrutiny from ENGOs. One of the only
references to GGREW activities in Israel and Australia comes from
Geoengineering Monitor [132], which argued that the effects on
biochemical processes and the marine food chain are unknown, and
insinuated that one of the project leaders, Tim Kruger, tried to market
ocean alkalinity enhancement with lime ‘since 2008’ and that his
company Cquestrate received early-stage funding from Shell. Although
trials never went ahead, critiques raise questions about the sufciency of
the project's governance focus on cost-benet analysis and life-cycle
assessment.
3.5.3. Mining-sector enhanced weathering
To explore trials in the mining sector, we distinguish between those
activities undertaken in open-air settings (where mine tailings are pro-
cessed to sequester carbon) versus more closed techniques, often
coupled with carbon capture and storage or direct air capture, which are
focused less on delivering long-term sequestration than providing a
feedstock for industrial activities – often referred to as “carbon miner-
alization” or “mineral carbonation”. We limit our discussion to cases
that are still at trial stage, take place in the open air, do not provide
feedstock for industrial processes, and are similar to efforts that me-
chanically or biologically foster an accelerated version of natural
weathering processes.
The FPX Nickel Corporation trials (EWM1) are undertaken by a
publicly traded mining rm (FPX Nickel Corporation) in collaboration
with university researchers (from the University of British Columbia).
Ongoing since 2019, the stated aim is for FPX Nickel to mitigate its
climate impact – and retain its social license – by developing the ‘world's
rst large-scale, carbon-neutral nickel operation’ [169,170]. Like other
enhanced weathering trials, the potential for co-benets is featured,
though in a more mining-specic fashion: including the possibility to
stabilize tailing pilings and reduce the amount of dust generated on
mining sites [171]. At present, there is no clear opposition to such
research – though it has been name-checked in a recent information
sheet put out by Geoengineering Monitor [132]. One key future impli-
cation is whether publicly traded rms in the mining sector, accountable
to shareholders and under increasing pressure to reduce their climate
impacts, might look more at enhanced weathering as a way to deal with
mine tailings, generate positive press, retain their social license to
operate, and pursue competitive advantage over international
competitors.
CarbonVault™ (EWM2) is a eld trial ongoing since 2020, funded by
the mining conglomerate DeBeers Group, at open-air mining sites within
South Africa and Canada [172–174]. Four types of enhancement are
considered: physical, biological, chemical, and ue gas injection [175].
Similar to FPX Nickel (EWM1), explicit co-benets include the potential
to stabilize waste tailings and reduce the amount of dust generated on
mining sites [171]. Framed as a project – together with academic part-
ners from Canada and Australia – to capture and store carbon and pave
the way for ‘carbon-neutral mining operations’ around the world, Car-
bonVault strives to develop ‘hybrid’ forms of enhanced weathering to
improve its effectiveness. While no discernible opposition is apparent,
the desire to explore an intersection between biotechnology and
enhanced weathering [175] seems ripe for controversy. Future reactions
to CarbonVault thus bear watching, to observe the effectiveness of
‘hybrid’ approaches and if such efforts attract strong backlash. The
presence of an internationally recognized rm in DeBeers Group –
notorious in certain circles – is also noteworthy for how this might affect
public discourse.
4. Strategies, framing, and stakeholder involvement across
technologies
The section above treated controversy as the result of contestations
over what issues, actors, expertise, practices, and rules should hold sway
over an experiment's or technology's development. In this section, we
highlight common themes that have motivated the emergence of con-
troversy and opposition across all the experiments in this study, and as
they are evolving over time. This section also discusses other qualita-
tively salient aspects of the cases including unconventional science,
indigenous knowledge and sovereignty, innovation, and jurisprudence.
We summarize these cross-experiment insights in Table 6. Furthermore,
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
10
we show in Fig. 2 a combined timeline of all technology clusters with
selected case studies.
4.1. Oppositional strategies led by key ENGOs
A key driver of opposition is an evolving alliance of ENGOs operating
across solar geoengineering and carbon removal technologies, often
independent of the specic type of experiment, location, or technology.
Opposition has in the last decade been spearheaded by the ETC Group,
the Heinrich B¨
oll Foundation, the Center for International Environ-
mental Law (CIEL), and the website Geoengineering Monitor. These
marshal the attention and efforts of a much larger ecosystem of ENGOs
who are less directly involved – but many of whom have a history of
opposing research or experiments into climate intervention or geo-
engineering since the earliest days of ocean fertilization. These ENGOs
are motivated – as are many scientists and other observers – by concerns
that all such approaches present incentives for delaying decarbonization
(or ‘mitigation deterrence’, see [176]), entrench inequities between
heavy emitters and the least-developed and vulnerable polities, and
reect a deeply illusory techno-optimism over the management of
complex natural systems (e.g. [177]).
A strategy for opposing experiments has reached a modular form
which can be imported for understanding and contesting new technol-
ogies and experiments. A rst key rationale and argument invokes both
the global and local dimensions of harm, highlighting experiments as a
slippery-slope towards geoengineering or as techno-xes or ‘geohacks’
for the carbon economy and its politics, coupled with more localized
issues of consent and socio-environmental impact. Another emphasizes
reference to the Convention on Biological Diversity's 2010 voluntary
guidance on restricting ‘climate geoengineering’ activities outside of
small-scale scientic activities (for exact language, see [178]) - which
the ETC Group and its allies describe as a UN-backed moratorium
[95,177]. Opponents pressure the government in whose territory the
experiment takes place, or to whose country the experiment's leading
institutions belong – targeting their reputation in global governance and
their alleged violation of international guidelines (usually, the ‘mora-
torium’ posed by [178]). These arguments in turn enroll an increasing
array of actors, from other ENGOs, social groups (e.g. indigenous peo-
ples), and media outlets, to surprised governments seeking to avoid
controversy (e.g. Canada in OF4, Germany in OF3, and Sweden in SAI3),
to bureaucrats and delegates at the international conventions at which
rulings on solar geoengineering and carbon removal research are being
developed (e.g. the Convention on Biological Diversity and London
Convention and Protocol).
Controversy arises most visibly when these tactics and arguments are
applied, even if their application remains selective. Moreover, the
greatest visibility is generated when ENGOs apply pressure – rather than
scientic networks, who maintain many of the same critiques, but not
the same tactics. Ocean fertilization and solar geoengineering appear to
have been strongly targeted so far; enhanced weathering has not. These
hallmark efforts force experiment planners and other actors – govern-
ments, international regimes – to react directly, as well as grapple with
the geoengineering label, a theme we return to in Section 4.3 on
camouage.
4.2. Strategies supporting experimentation, and societal appraisal
The arguments and governance procedures employed by experiment
planners are also coalescing over time. A conventional-scientistic
framing emphasizes the small scale of current experiments, deter-
mining de minimis impact thresholds for being allowed to conduct them
(larger-scale terrestrial enhanced weathering activities appear to be the
exception here, e.g. EWT1–4), university-based review procedures
(MCB1, EWO1), and the separation of technical scientic work from
political and commercial contexts via independent advisory panels, as-
sessments and reviews, and institutional communications that include
websites and public-facing briefs (OF2, OF3, SAI3, EWO2). Deliberately
or implicitly, and regardless of the technology or approach tested, these
efforts frame experiments as assessments that neutrally inform rather
than purposefully shape decision-making, and bound the risks as tech-
nical and localized rather than socio-political and potentially far-
reaching. As such, they are more facilitative representations of experi-
mental work.
Unlike the oppositional ENGOs who clearly foreground their shared
purposes (Section 4.1), the motives of experiment planners across case
studies are varied and difcult to aggregate. Scientic researchers may
hold a resilient conception of their work as explorative assessment that
does not prescribe political action, while similarly rejecting the need for
stronger oversight. They may also be well aware of the political or
commercial implications, and instrumentally deploy arguments and
procedures that minimize the need for scrutiny or seek to create a more
favorable reception. It can be very difcult to distinguish one from the
other.
In recent cases, facilitative framing efforts are more clearly pre-
emptive, evolving alongside and anticipating critique (for example, in
SAI3, see [109,179] for supportive arguments). Moreover, the justi-
cations behind experiments are shifting as well, from emphases on
technical assessment to clearer couplings with decision-making or
commercial activities – posing new rationales for critics to scrutinize,
and incentives for planners to forestall controversy. Justication for
stratospheric aerosol injection eldwork contains the strongest policy-
oriented argumentation and is incorporated as such into an inuential
Table 6
Strategies, framing and stakeholder involvement across technologies.
Section Generalizable themes
4.1 Oppositional strategies led by
key ENGOs
•Modular strategy for contesting
experiments: Slippery slope towards global-
scale climate interventions; Local harms;
Lack of consent; Reference to a UN ‘mora-
torium’; Pressure ‘hosting’ governments
•Currently most applied by an
environmental NGO network
•Many critical scientists advance similar
concerns, but do not employ the same
tactics
4.2 Strategies supporting
experimentation, and societal
appraisal
•Conventional-scientistic defense of
experiments: Thresholds and ‘safe zones’;
University-/expert-based reviews; Need to
separate basic science from political and
commercial intent
•Societal appraisal (e.g. Responsible
Research and Innovation) becoming a key
motif of governance
•‘Societal appraisal’ contested: e.g. Open-
ended towards risk conceptions, critically-
oriented ‘slow science’ vs. instrumental
engagement on more bounded conceptions
of risk
4.3 The framing of basic science or
co-benets, and ‘camouage’
•Outside of stratospheric aerosol
experiments, experimenters deemphasize
the term ‘geoengineering’
•Framings include: early-stage basic science,
co-benets with local economy, and eco-
restoration and protection
•Is this ‘camouage’?
4.4 Citizen, indigenous, and
entrepreneurial involvement
•New actors and their agendas, concerns,
and practices becoming prominent in
experimentation: citizen science,
indigenous actors (as a proxy for deeply
localized actors and knowledge), and
entrepreneurs, innovation, and industry
4.5 Rules of jurisdiction and
jurisprudence
•Different bodies of norms and law stipulate
different rules for ‘legitimate’
experimentation
•Possibility for jurisdiction-shopping
•What are latent or emergent bodies of
regulation?
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Fig. 2. Themes from selected case studies across technologies and time.
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report by the US National Academies of Science ([74] for a critique, see
[96]). Defenses of experimentation as scientic or technical have also
been expanded by innovation-facing actors, historically in ocean fertil-
ization, and increasingly in enhanced weathering (see Section 4.4,
particularly Project Vesta, EWO2).
To engage with the concerns that motivate critique, research net-
works grounded in public engagement and critical social sciences
emphasize the need for additional forms of societal appraisal – often
referring to frameworks for governance of emerging technologies
[22,180–183]. Practitioners of these frameworks often focus on the so-
cietal implications of science and innovation, and to reect this, call for
the inclusion of new kinds of expertise, stakeholder types, and rules of
scientic conduct. Societal appraisal reects efforts to forestall contro-
versy by creating assessment, innovation, and decision-making that are
more attuned to a wide range of demands and concerns. Still, the role
and necessity of such frameworks are not settled in carbon removal and
solar geoengineering experimentation. Experiment designers and op-
ponents appeal to different understandings of what a safe and legitimate
experiment is, and call for or ignore societal appraisal processes
accordingly.
A key example is the responsible research and innovation (RRI)
framework proposed by Stilgoe et al. [22], building on the ‘stage-gate’
review process of the SPICE test-bed (SAI2). The rationales for societal
appraisal mirror oppositional arguments: rstly, that even technical,
small-scale, and early-stage activities need to gain the input and consent
of local stakeholders; secondly, that planners must anticipate rather than
elide the potentially far-reaching political implications of their work.
This is a direct response to the physical thresholds and allowed zones
sought by some researchers that are more facilitative towards experi-
ments (compare [179] to [22,27]).
SPICE (SAI2), LC3M (EWT2), WLIC (EWT3) and OceanNETs (EWO3)
have adopted RRI-avoured protocols, with OceanNETs providing an
open-ended invitation via its Stakeholder Reference Group form for
interested parties to consult and take part and WLIC collaborating with
actual farmers, ranchers, and tribes, whose lands serve as the sites of
trials. But there is no consensus around either the need for or shape of
this mode of societal appraisal, with planners appealing to different
understandings of the technical value and wider risks of experiments to
shape their engagements with stakeholders. Many past and planned
experiments focus on mitigating technical or environmental impacts,
and are limited to institutional reviews, or engineering or impact
assessments.
Other experiments challenge the RRI template: in comparison to the
SPICE stage gate (SAI2), the SCoPEx team (SAI3) deemed grappling with
future political implications too vague and restrictive, instead asking for
concrete, instrumental questions to guide public engagement. Indeed,
many scientists behind the scenes regard SPICE's review process as
overly burdensome (SAI2). What is more, for all their efforts, the SPICE
team did not appear to be successful in addressing ENGO concerns.
Other initiatives, such as MCB experimentation over the Great Barrier
Reef (MCB3) or Project Vesta (EWO2), have subsequently developed
their own stakeholder engagement plans – though fewer details are
available. But these operate under different governance jurisdictions
and have so far avoided the geoengineering label, not to mention being
largely overlooked by ENGOs – a comparison on effective societal
appraisal is thus hard to make. And arguably the most in-depth and
tailored engagement with local populations and authorities was con-
ducted by the Haida Salmon Restoration Corporation (OF4), which ul-
timately had a mixed record: winning the local license it deemed
relevant, but at the expense of a loss of reputation and credibility in the
global context.
Stakeholder engagement is therefore becoming a motif of experi-
mental governance, but it is unclear how many experiments favor open-
ended appraisal and ‘slow science’ [9], perhaps with the clear and
obvious exception of OceanNETs (EWO3). Emerging engagement pro-
cesses may be robust; they may also disguise more instrumental forms of
acceptance research or traditional scientic communication. RRI-
informed societal appraisal certainly appears to motivate its own prac-
titioners more so than the bulk of actors in science and industry [106].
For some of the more commercially inclined projects, engagement is an
ad hoc solution that skirts the edges of stakeholder outreach (e.g. the
‘smart monitoring concept’ of Project Carbdown, EWT4).
4.3. The framing of basic science or co-benets and ‘camouage’
Another theme from our QCA surrounds efforts to contest the geo-
engineering label. For research advocates, experiments may connect
eventually to a large-scale or even planetary enterprise, but experiments
themselves do not ‘geoengineer’ – they develop knowledge that lls in
scientic blanks, reduces costs, and enables us to mitigate climate
change (see quote by Tom Green of Project Vesta, EWO2), or informs
whether upscaling could or should be done in the future (e.g. OF3 and
SAI3).
Self-labeling as ‘geoengineering’ therefore remains a key choice in
framing experiments. The original framing of all solar geoengineering
and carbon removal approaches as forms of deliberate and large-scale
interventions [1] is breaking up as carbon removal has become
normalized over solar geoengineering in post-Paris assessment, and as
more regional- or local-scale approaches more rmly based in techno-
logical carbon removal or ecosystems management are coming to the
fore. However, advocates of research into ocean fertilization and
stratospheric aerosol injection still nd it difcult to shake the label of
marine or solar geoengineering. Moreover, there are terrestrial carbon
removal approaches where implementation at large scale would make
the geoengineering label accurate. The ‘splitting’ and ‘lumping’ of the
umbrella term is far from settled.
Still, it is not only the technical accuracy of geoengineering that is
relevant, but the term's association with the large-scale manipulation of
the (human) environment, and its function as a shorthand for supposed
time-buying strategies that permit the continued exploitation of fossil
fuels. In earlier ocean fertilization and marine cloud brightening ex-
periments, basic science – the biological pump of phytoplankton, or
cloud dynamics – was a typical framing. Today, experiments outside of
stratospheric aerosol injections are increasingly framed around coupling
and co-benets, with this being especially true for those on enhanced
weathering. Ocean fertilization experiments – through framings of
‘ocean nourishment’ and ‘ocean seeding’ – now lean into restoring
marine ecosystems and sheries, and quietly maintaining the possibility
for carbon sequestration and crediting [68]. In solar geoengineering
work, marine cloud brightening experimentation in the Great Barrier
Reef (MCB3) is integrated within a broad range of equally novel adap-
tive and resilience measures [184]; the Arctic Ice Project frames itself
similarly (IP1). None of these projects mention marine or climate
geoengineering.
Emerging enhanced weathering projects have tended to avoid the
issues associated with the term “geoengineering” by highlighting
entwined relevance for coupling with agriculture, mining operations,
carbon crediting (EWT3, EWT4, EWO2), and supposedly addressing is-
sues most in need of climate-mitigation efforts [129,185]. Concerning
agriculture, enhanced weathering materials are envisioned as sub-
stitutes for costly fertilizer inputs, their application argued to thereby
enhance soil fertility and crop yields – while also building on existing
processes and infrastructure (EWT1, EWT2, EWT3, EWT4). Sourcing of
materials for terrestrial enhanced weathering is notable for attempts to
utilize waste materials from mining processes. This positioning seems to
dodge questions of potential energy and water use while nestling up to
politically popular concepts like the ‘circular economy’. In the context of
mining, the prospect of reduced GHG emissions and waste has been
directly pointed to as a potential source of international competitive
advantage (EWM1, EWM2), while ocean alkalinity enhancement is
highlighted as a means to address ocean acidication or provide pro-
tection for the Great Barrier Reef (EWO1, EWO4). The supposed redress
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of such salient issues or iconic locations acts as a considerable political
selling point.
Basic science and co-benets framings act as ‘social camouage’,
where technologies can be described instrumentally or implicitly as
something else to win societal license or avoid debate, and the condi-
tions that might generate opposition are circumvented [186,187].
4
Here, this regards association with the ‘geoengineering’ label. But it is
important to note that it is difcult to pinpoint whether use of such
camouage is deliberate or functional. There is a blurry line between
avoiding associations with geoengineering and an accurate description
of an experiment's intended motivations, e.g. towards co-benets to
encourage uptake by specic industry or resident groups. This is espe-
cially true for carbon removal approaches based in natural environ-
ments. Still, the record of camouage when it comes to avoiding
controversy is inconclusive – some experiments were connected only
belatedly (e.g. MCB1, MCB3), while others (e.g. enhanced weathering
experiments) are still evolving in the public eye. The debate on cam-
ouage will depend on whether the technical and political dimensions of
approaches as disparate as marine cloud brightening and enhanced
weathering are sufciently resolved, such that a critical mass of actors
comes to (dis)associate them with deliberate, large-scale climate
interventions.
4.4. Citizen, indigenous, and entrepreneurial involvement
Experiment planners and stakeholders reect an increasingly diverse
range of actors. Three participatory fault lines are emerging around who
is permitted to frame their efforts within the cover of ‘legitimate’ sci-
ence. Buck [17], in her engaging study of Russ George and the Haida
Salmon Restoration Corporation (OF4), identies two of these. The rst,
represented in the extreme by George, is the demarcation between the
science produced by publicly funded scientic institutions (e.g. uni-
versities, scientic societies, and national research agencies) and that by
individuals and networks without such accreditation. These could be
enthusiasts with practical experience rather than formal training; they
might possess appropriate qualications but lack an institutional home.
Beyond carbon removal and solar geoengineering experiments, this
connects to conversations about the value of ‘citizen science’ in gener-
ating new angles of inquiry, increasing basic literacy in complex scien-
tic issues, or unsettling previous results. But such work, if lacking in
rigor, or if displaying intent and yielding results contrary to those of
established scientic institutions, is readily derided as ‘rogue science’
[17]. Activities of citizen science in solar geoengineering and carbon
removal appear limited, mostly to actors in ocean fertilization; in this
limited sample, the fears of more established scientists appear borne out.
But as the range of experimentation and framings expand, there remain
lurking questions on the line between stewardship and gatekeeping.
The second can be seen in indigenous actors: the Haida (OF4), the
Saami (SAI3), and the Pauma Band of Luise˜
no Indians as well as the
Intertribal Agricultural Council (EWT3). These peoples and their rep-
resentatives played different roles – Haida authorities and communities
were key planners in the HSRC experiment, while the Saami Council
staunchly opposed ScoPEx. But both point to the signicance of local
jurisdictions in the framing and appraisal of experiments, and highlight
that technical work is richly and alternatively depicted (and for the
Haida, motivated) by entwined understandings of local culture,
economy, and environment. For the Haida, the experiment also lever-
aged a historic alienation to the Canadian polity – colonialism, and the
then-government's questionable commitment to climate mitigation –
that may have bled into how established scientic processes were
viewed [60]. We should recognize the implications for locally-grounded
social groups more broadly. The indigenous tend to be historically
marginalized from conventional assessment and policy processes; they
bring resonantly local institutions and networks to bear; they confront or
combine established science with alternative knowledge systems. These
dimensions are increasingly recognized through ‘Indigenous and Local
Knowledge’ in global environmental assessments [188]. Scientic net-
works – especially experiment planners and their governance processes
– should be wary of token or instrumental use of local actors, whether to
defend or detract from experiments, or solar geoengineering and carbon
removal as climate strategies.
A third fault line describes the rise of entrepreneurial actors, aes-
thetics, and business and funding models in the conduct of research and
experimentation. These embody a broad range: individuals and net-
works in ‘citizen science’ (e.g. Russ George), NGOs and non-prots
engaged in research advocacy and funding (e.g. Silver Lining at MCB2,
Leverhulme Centre for EWT2), hybrid initiatives linking scientic and
commercial work (e.g. OF2, OF4, EWT4, EWO2) and industry actors and
corporations (e.g. EWM1, EWM2). Entrepreneurial actors are more
attuned to dimensions of self-advertisement, self-labelling and branding,
and camouage: rejecting geoengineering, stressing business and local
development co-benets, often with an eye towards policy development,
and buying time for mitigation.
These arguments leverage and expand the rationales long used by
scientic actors to justify further research and experimentation (Section
4.2). Many entrepreneurial actors have sought connections with con-
ventional scientic networks for legitimacy; others have leveraged their
projects as attacks upon the supposed gatekeeping efforts of scientic
institutions. But most have developed business- and innovation-oriented
objectives beyond traditional scientic activity: development and pat-
enting of approaches (OF2, IP1, EWO2), or carbon crediting and ac-
counting approaches in carbon removal projects (numerous examples
within ocean fertilization and enhanced weathering), or an orientation
towards Silicon Valley networking and philanthropy to generate visi-
bility and funding (e.g. Silver Lining at MCB2, Project Vesta at EWO2).
Scientists have displayed unease with these modes: marine-science
communities largely circumvented arguments favoring commercial
ocean fertilization and, more recently, personnel from solar geo-
engineering experiments (e.g. SAI2 and SAI3) have rejected patenting.
At the same time, two factors will continue to drive involvement of
entrepreneurial actors: the funding-starved landscape of solar geo-
engineering work, where the capacity to motivate and organize phil-
anthropical contributions remains signicant (e.g. Silver Lining at
MCB2), and the proliferation of carbon removal approaches framed in
terms of purported co-benets with local development and couplings
with industry and innovation, including as a means to much-needed
climate neutrality.
4.5. Rules of jurisdiction and jurisprudence
A nal dimension regards the formation, interpretation, or selective
choice of the rules that apply to experiments. These range from legal
stipulations to informal but resonant conventions whose applications
depend on the actors engaged in an experiment's planning and gover-
nance, as well as where it is held.
Some experiments have been held wholly within a country's terri-
torial boundaries and should thus comply, according to the literature,
with domestic law on pollution, environment, and liability [189,190].
The solar geoengineering experiments in Russia (SAI1) and Australia's
Great Barrier Reef (MCB3) were conducted with the approval of national
agencies - although due to perceived Russian geopolitical aims, the ca-
pacities for domestic law and governmental oversight to provide
4
The original insight comes from Maines [186,187], whose research was on
how the early vibrator's applications were couched within medical terminology
and uses to gain acceptance in a more conservative society. The more general
insight - camouage circumvents rather than engages with the conditions that
might create controversy - is without prejudice to the technology or issue in
question. We might consider that within the climate domain, emissions re-
ductions measures are increasingly ltered through co-benets to air pollution,
local development, and ecosystems services.
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Energy Research & Social Science 90 (2022) 102594
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transparent governance are regarded differently in the two cases.
Enhanced weathering experiments, furthermore, have been entirely
located within national boundaries, but their compliance with bodies of
domestic law remain unclear, even where benets of such projects have
been framed in terms of the international competitiveness of certain
domestic sectors (EWT1, EWM1; note: interestingly, both with regard to
Canada). At the same time, experiments conducted on indigenous lands
(MCB3; SAI3; IP1) or planned by or in collaboration with indigenous
actors (OF4, EWT3) highlight the relevance of sub-state jurisdictions -
these may not always have a formal legal character, but constrain ex-
periments through local governance procedures and resonant cultural
understandings.
Activities occurring beyond or across national boundaries - for now
limited to ocean fertilization experiments in international waters - are
also subject to international frameworks. The Convention on Biological
Diversity (CBD) is a guidance for restricting ‘geoengineering’ to scien-
tic activity, but it is vague and voluntary [178,191]. The London
Convention and Protocol (LC/LP, governing marine pollution) devel-
oped an initially non-binding 2008 decision on ocean fertilization into a
2013 amendment for binding regulation of ‘marine geoengineering’
[192,193], with new approaches being examined by its scientic advi-
sory body [71,194] – but it remains restricted to the marine environ-
ment. Atmospheric regimes (e.g. ozone and transboundary air pollution)
have relevant mandates for solar geoengineering activity, but remain
uninvoked. Engagement is being sought at the UN Environmental As-
sembly [27,93] and UN General Assembly [195]. Curiously, discussion
at the UNFCCC itself has been limited - the Paris Agreement implicates
carbon removal [196], but solar geoengineering has never been raised in
formal discussion. The objective and enforceability of regulation that
each of those venues might provide would differ as well.
The result is a legal patchwork of potentially relevant binding and
customary laws, spread across bodies of national legislation and inter-
national regimes with overlapping mandates - only a tiny fraction of
which has specically considered geoengineering experiments
[190,194]. Some, like evolving decisions at the CBD and LC/LP, have
been invoked by experiment opponents, but none have been tested. One
danger of this is jurisdictional or forum shopping for the laws, deni-
tions, and politics most favorable to the agendas of experiment planners
or opponents [197,198]. The ETC Group repeatedly cites the CBD's 2010
decision as a moratorium, due to its long engagement in that forum.
Lohafex (OF3) was compelled to adjudicate between the differing de-
nitions on allowable scientic research posed by the CBD and the LC/LP
[199]. And the experiments in Russia (SAI1) and Australia (MCB3)
present alternative scenarios for the national oversight of experiments,
and even deployment.
5. Conclusion
Planetary-scale ‘geoengineering’ remains a key motif for the
contestation of early-stage experiments. The ‘geoengineering’ label is
increasingly rejected by experiment planners on several grounds: the
difference in intent and impact between research and deployment, dis-
parities between solar geoengineering and carbon removal approaches,
and co-benets with industry and local development and ecosystems.
For many scientic and commercial actors, ‘geoengineering’ does not
facilitate their goals of integrating plural approaches into assessment,
development, and policy at multiple levels. But it can be unclear when
camouage is deliberate or implicit. Certainly, projects that frame
themselves as beyond geoengineering, or that emphasize other com-
munity co-benets, garner less social opposition. On the other hand,
camouage also reects a more granular, t-to-purpose range of usage
descriptions.
For those who remain wary of prioritizing technical criteria and
near-term policy and business integration, geoengineering remains a
resilient guiding concept for large-scale ‘human ecosphere in-
terventions’ [3]. Indeed, all small-scale experiments investigate
components of what are intended to be regional- or global-scale in-
terventions; some with minimal transparency or wider consultation, and
many with unclear incentives couched within the language of ‘co-ben-
ets’. Geoengineering is an elastic concept that incorporates new ap-
proaches as they emerge, and will continue to be invoked by ENGOs and
scientists concerned about techno-optimism, the erosion of natural en-
vironments, and the inequities of the carbon economy. Experiment
planners may wish the term away, but the concerns that motivate its use
may still reappear under a different name – especially given the political
allure of ‘silver bullet’ solutions to climate change.
Incoming actors must grapple with these dimensions. Geo-
engineering, as a term, does not need to be a pillar of an experiment's or
project's framing – but the concerns about local or global inequities that
motivate its use must not be dodged. With the rise of stakeholder
engagement and consent as benchmarks in experimental conduct,
entrepreneurial actors and funding models, and a proliferation of ap-
proaches and spaces in which experiments can be planned, new actors
and jurisdictions are coming into play. In a plethora of local groups,
national boundaries, and forms of international guidance, the key
question is: Whose consent is relevant? Jurisdiction shopping, token
stakeholder engagement, and issues surrounding philanthropy and
commercial orientations present dangers for not only the legitimacy of
experiments, but for the distribution of their outcomes.
Can the principles of societal appraisal be of aid to experiment
planners in gaining feedback from local stakeholders, and even from
entrenched critics? Even if a particular experiment side-steps immediate
attention, it may inuence how opposition engages with future projects
of a similar kind. Experiments would do better to engage up front with
the conditions of opposition, beginning with the engagement of local
stakeholders as a prerequisite, informed by the input of global scientic
and NGO networks. Planners can map and point to local co-benets and
risks – while also anticipating the perverse incentives and uncertainties
of large-scale implementation, with dialogue and mitigatory measures
built in as early as possible [200].
In closing, we highlight avenues for future research. We have
attempted a broad mapping of issues, actors, and tactics for social
contestation, across a range of early-stage experiments assessing
immature approaches into climate intervention. The wide scope of our
study shows that key actors, oppositional and defensive drivers and
tactics, proposed frameworks for societal appraisal, as well as issues of
unconventional science, indigenous knowledge and sovereignty, entre-
preneurial motives, and appropriate jurisdiction are common and
comparable across all the technologies, experiment types, and locations
assessed. Our mapping brings together insights from past analyses
[9,17–20], and lays the groundwork for studies that embrace greater
empirical, methodological, and conceptual novelty.
Empirically, the number of experiments in these technological clus-
ters will likely expand – enhanced weathering projects are rapidly
increasing, while marine-based initiatives framed as ‘eco-restoration’
encompass new ocean fertilization projects, ocean-based enhanced
weathering, and marine cloud brightening. Future inquiry could
encompass pilots and prototypes for direct air capture or bioenergy
carbon capture and storage, exploring if the same motivating issues and
actors remain resonant. It will be especially important to map the en-
gagements of commercial actors coming to the fore across multiple
technologies. Comparative technologies could extend beyond carbon
removal and solar geoengineering into areas of prior controversy – such
as genetic modication in food or nuclear power. Indeed, we identify
one potential overlap between biotechnology and enhanced weathering
in open-air mines (EWM2), where the former is being employed to
develop novel microbes that enhance the efciency of weathering pro-
cesses. New emphases on ‘co-benets’ between emerging technologies
could further highlight such intersections.
Methodologically, in-depth ethnographical work and site visits could
be undertaken with experiment planners and/or oppositional actors, to
shed new light on the mostly secondary analyses of this paper.
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Engagements can also be further undertaken with decision-makers,
publics, and other ‘users’ of the knowledge at the core of the experi-
ments, that is, to inform how experiments should be designed or to
better incorporate the concerns of stakeholders.
Conceptually, our mapping provides a foundation for further critical
and normative work, evaluating experiments and their motivating issues
in relation to justice [27] or the Sustainable Development Goals. Studies
can also more strongly probe the shaping and emulative effects that the
design of prior experiments – and the conduct of the scientic, com-
mercial, and civic networks engaged therein – holds for future experi-
mental practice or legal guidelines. Such inquiry would supplement our
analysis of how key rationales and tactics underpinning the contestation
of experiments have spread across time and technology through the
operation of common networks and discourses (Sections 4.1–4.4).
Ultimately, our study reminds us that experiments into climate in-
terventions do not occur in a techno-economic vacuum. We appeal to
experiment or pilot planners, when confronted with choices over how to
engage with societal appraisal or the political implications of research,
to consider: Even if they themselves do not see far-reaching and un-
certain implications of small-scale research, or global implications in
relation to geoengineering, projects wishing to more cynically avoid
scrutiny may choose to emulate their tactics and framings. The insular
motives of one are a gamble for others, or even all. Rather, planners
should seek to create and share best practices that can evolve alongside
the relationship between society and emerging science on climate
interventions.
Declaration of competing interest
The authors declare that they have no known competing nancial
interests or personal relationships that could have appeared to inuence
the work reported in this paper.
Acknowledgments
This project has received funding from the European Union's Horizon
2020 research and innovation programme under the European Research
Council (ERC) Grant Agreement No. 951542-GENIE-ERC-2020-SyG,
“GeoEngineering and NegatIve Emissions pathways in Europe” (GENIE).
The content of this deliverable does not reect the ofcial opinion of the
European Union. Responsibility for the information and views expressed
herein lies entirely with the author(s). We thank the reviewers for their
invaluable feedback, Benjamin Mitterrutzner for assistance with the
gures, and Andy Parker for suggesting the title.
Annex 1. 44 existing or planned early-stage experiments into radical climate interventions from 1990 to present, narrowed to 21 for in-
depth study via qualitative comparative analysis
Experiment/main Host Technology Year and location Brief detail; included or excluded as in-depth cases
IronEX I (Moss Landing Marine Laboratories) Ocean iron fertilization 1993; Eastern equatorial Pacic
Ocean
Established proof of iron-seeded phytoplankton blooms.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
IronEX II (Moss Landing Marine Laboratories) Ocean iron fertilization 1995; Eastern equatorial Pacic
Ocean
Conrmed proof of iron-seeded phytoplankton blooms.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
Ocean Farming Ocean iron fertilization 1998; Gulf of Mexico Early actor in commercial ocean fertilization, whose
founder later started Green Sea Ventures.
Excluded – no record of controversy could be analyzed, and
documentation of its mode of experiment and governance
does not exist. However, elements thereof may be
contained in Planktos, OF1 and Climos, OF2.
SOIREE- Southern Ocean Iron Enrichment
Experiment (University of Otago)
Ocean iron fertilization 1999; Southern Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
Green Sea Ventures Ocean iron fertilization 1998; Equatorial Pacic Early actor in commercial ocean fertilization.
Excluded – no record of controversy could be analyzed, and
documentation of its mode of experiment and governance
does not exist. However, elements thereof may be
contained in Planktos, OF1 and Climos, OF2.
CarbonCorp USA Ocean fertilization
patented nutrient
supplement
Founded late 1990s; No
experiments conducted.
Early actor in commercial ocean fertilization. Ideas
inherited by Ocean Carbon Sciences.
Excluded – no record of controversy could be analyzed, and
documentation of its mode of experiment and governance
does not exist. However, elements thereof may be
contained in Planktos, OF1 and Climos, OF2.
Ocean Carbon Sciences Ocean iron fertilization Founded early 2000s; No
experiments conducted.
Early actor in commercial ocean fertilization. Pledged to
take part in SERIES; later reneged.
Excluded – no record of controversy could be analyzed, and
documentation of its mode of experiment and governance
does not exist. However, elements thereof may be
contained in Planktos, OF1 and Climos, OF2.
EisenEX (Alfred Wegener Institute) Ocean iron fertilization 2000; Southern Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
Ocean iron fertilization 2001; Southern Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
(continued on next page)
S. Low et al.
Energy Research & Social Science 90 (2022) 102594
16
(continued)
Experiment/main Host Technology Year and location Brief detail; included or excluded as in-depth cases
SEEDS I - Subarctic Pacic Iron Experiment for
Ecosystem Dynamics Studies (University of
Tokyo)
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
SOFex - Southern Ocean Iron Experiment, North
and South (Moss Landing Marine
Laboratories)
Ocean iron fertilization 2002; Southern Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
Planktos I Ocean iron fertilization 2002; Gulf of Alaska Early actor in commercial ocean fertilization. First of Russ
George's ‘citizen science’ efforts.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Planktos II, OF1.
SERIES - Subarctic Ecosystem Response to Iron
Enrichment Study (Laval University)
Ocean iron fertilization 2002; Gulf of Alaska Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
CYCLOPS - Cycling of Phosphorus in Eastern
Mediterranean (University of Leeds)
Ocean fertilization with
phosphorus
2002; Eastern Mediterranean Investigated the use of phosphorus in place of iron.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
EIFEX - European Iron Fertilization Study
(Alfred Wegener Institute)
Ocean iron fertilization 2004; Southern Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
SEEDS II - Subarctic Pacic Iron Experiment for
Ecosystem Dynamics Studies (University of
Tokyo)
Ocean iron fertilization 2004; Subarctic Pacic Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
FeeP (Unclear) Ocean iron fertilization 2004; Subtropical Northeast
Atlantic Ocean
Investigated interaction between phosphorus and iron.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
SAGE - SOLAS Air–Sea Gas Exchange
experiment (University of Otago)
Ocean iron fertilization 2004; Southern Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
KEOPS 1 - Kerguelen Ocean and Plateau
compared Study (Centre National de la
Recherche Scientique)
Ocean iron fertilization 2005; Southern Indian Ocean Investigated phytoplankton carbon sequestration at
expanded scale and process.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
Planktos II Ocean iron fertilization 2007; Near Galapagos Islands Included as OF1, Section 3.1 – marked by clear
controversy.
Climos Ocean iron fertilization No experiments conducted. Included as OF2, Section 3.1 – was mentioned in the same
breath as Planktos, despite a lack of experiments
conducted.
Lohafex (Alfred Wegener Institute) Ocean iron fertilization 2009; Southern Ocean Included as OF3, Section 3.1 – marked by clear
controversy.
KEOPS 2 - Kerguelen Ocean and Plateau
compared Study (Centre National de la
Recherche Scientique)
Ocean iron fertilization 2010; Southern Indian Ocean Unclear signicance as an experiment.
Excluded – no record of controversy could be analyzed, and
its mode of experiment and governance is summarized in
Lohafex, OF3.
Haida Salmon Restoration Corporation Ocean iron fertilization 2012; Northwest Pacic Ocean Included as OF4, Section 3.1 – marked by clear
controversy.
Ocean Nourishment Corporation Ocean fertilization with
macronutrients
Unclear if any experiments
conducted.
Framing of ocean fertilization as ecosystems restoration
with co-benets for local development and science, and
time-buying for mitigation, with lingering elements of
commercial ocean fertilization.
Excluded due to lack of information, but mentioned in
Section 3.1.
Oceanos Ocean iron fertilization Unclear if any experiments
conducted.
Framing of ocean fertilization as ecosystems restoration
with co-benets for local development and science, and
time-buying for mitigation, with lingering elements of
commercial ocean fertilization.
Excluded due to lack of information, but mentioned in
Section 3.1.
E-PEACE - Eastern Pacic Emitted Aerosol
Cloud Experiment (University of California
San Diego)
Marine cloud brightening 2011; Monterrey, California, USA Included as MCB1, Section 3.2 – raised no signicant
controversy at the time, but inuenced the design and
contestation of experiments,
Marine Cloud Brightening Project (University of
Washington)
Marine cloud brightening Delayed since 2018; Monterrey,
California, USA
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Energy Research & Social Science 90 (2022) 102594
17
(continued)
Experiment/main Host Technology Year and location Brief detail; included or excluded as in-depth cases
Included as MCB2, Section 3.2 – no experiments
conducted, but inuences the design and contestation of
experiments.
Marine Cloud Brightening for the Great Barrier
Reef (Southern Cross University)
Marine cloud brightening 2020; Great Barrier Reef, Australia Included as MCB3, Section 3.2 – no controversy was raised,
but inuences the design and contestation of experiments.
Yuri Izrael's Field Experiment on Studying Solar
Radiation Passing through Aerosol Layers
(Roshydromet and Russian Academy of
Sciences)
Stratospheric aerosol
injection
2008; Saratov, Russia Included as SAI1, Section 3.3 – no controversy was raised,
but inuences the design and contestation of experiments.
SPICE ‘Test bed’- Stratospheric Particle
Injection for Climate Engineering (Bristol
University)
Stratospheric aerosol
injection
2012; Norwich, UK Included as SAI2, Section 3.3 – marked by clear
controversy.
SCoPEx -
Stratospheric Controlled Perturbation
Experiment (Harvard University)
Stratospheric aerosol
injection
Suspended 2021; Kiruna, Sweden Included as SAI3, Section 3.3 – marked by clear
controversy.
Arctic Ice Project Hollow glass microspheres Since 2017 in Alaska and
Minnesota, USA; planned for
Manitoba, Canada and Svalbard,
Norway
Included as IP1, Section 3.4 – no controversy was raised,
but inuences the design and contestation of experiments.
Guelph wollastonite trials (Guelph University) Enhanced weathering
(agricultural)
2015–2018 (and ongoing);
southern Ontario, Canada
Included as EWT1, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
Leverhulme Centre for Climate Change
Mitigation (LC3M) (University of Shefeld)
Enhanced weathering
(agricultural)
Since 2018; Illinois, United States,
north Queensland, Australia and
Malaysian Borneo
Included as EWT2, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
Working Lands Innovation Center (UC Davis) Enhanced weathering
(agricultural, with biochar
and compost)
Since 2019; multiple sites across
California and one site in New York
Included as EWT3, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
Project CarbDown Enhanced weathering
(agricultural, with biochar)
Since 2020; across EU (i.e. Greece,
Germany, Netherlands)
Included as EWT4, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
One Tree Reef (Carnegie Institution for Science) Enhanced weathering
(ocean)
2014; Great Barrier Reef, Australia Included as EWO1, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
Project Vesta Enhanced weathering
(coastal, ocean)
Delayed to late 2021; undisclosed
coves in the Caribbean
Included as EWO2, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
OceanNETs (GEOMAR Helmholtz Centre for
Ocean Research Kiel)
Enhanced weathering
(ocean)
Planned to start in 2021; Canary
Islands
Included as EWO3, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
GGREW (University of Oxford, Cardiff
University, University of Southampton,
University of Cambridge)
Enhanced weathering
(ocean)
Suspended 2020 (due to COVID);
Gulf of Eliat, Israel and Great
Barrier Reef, Australia
Included as EWO4, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
FPX Nickel Corporation Enhanced weathering
(open-air mines)
Since 2019; Decar Nickel District
and Vancouver, Canada
Included as EWM1, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
CarbonVault™ (De Beers Group) Enhanced weathering
(open-air mines)
Since 2020; Venetia mine in South
Africa and Gaucho Ku´
e in Canada
Included as EWM2, Section 3.5 – no controversy has been
raised, but inuences the design and contestation of
experiments, and embody interesting dynamics for future
experiments.
Source: Authors, with information on ocean fertilization experiments taken from Strong et al. 2009 and Williamson et al., 2012. The table shows: After screening 44
experiments or projects with planned experiments within these technological clusters undertaken or announced from 1990 to 2020/2021, we select 21 as in-depth case
studies. Our choice of case studies is guided by two criteria. We focus on (planned) experiments that have been confronted by visible controversy and opposition.
However, from the vantage point of 2021, we also look at experiments which raised no signicant controversy at the time, but with hindsight have become more
controversial, have clearly inuenced the design and contestation of experiments, or continue to embody interesting dynamics for future experiments. We chose to be
extensive as possible in our coverage of enhanced weathering cases, as it is the newest of the technological clusters.
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