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Biochar Sustainability and Certification



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Biochar sustainability and certification
Frank G. A. Verheijen, Ana Catarina Bastos, Hans-Peter Schmidt,
Miguel Brandão and Simon Jeffery
In order to appreciate what is involved in devel-
oping certification of sustainable biochar pro-
duction as well as sustainable environmental
biochar application, this chapter starts by
explaining what sustainability policy entails,
before applying and extending priority and
cross-cutting bioenergy sustainability criteria to
biochar. The three existing nascent sustainable
biochar production certification schemes are
then briefly compared, before the concept and
challenges regarding certification of environ-
mental biochar application are presented and
discussed. In this context, two approaches are
put forward and analysed for their potential use-
fulness in the development of certification sys-
tems that include both components of biochar
sustainability (i.e. production and environmental
application), such as the concept of an Optimum
Biochar Dose and life cycle approaches.
What is sustainability?
Sustainability is an almost ubiquitous word in
science, as well as society, today. Brown et al
(1987) reviewed the then trendy term ‘sus-
tainability’ and discussed different interpreta-
tions from a range of fields. For example, in
forestry the term has been used since the
beginning of the twentieth century in the con-
text of ‘maximum sustainable yield’, meaning
‘the maximum annual harvest while still
ensuring that the rate of felling equals the rate
of replacement in a given area’. In agricul-
ture, the concept of sustainability has shifted
the productivity goals during the twentieth
century from maximizing production in the
short term to the long-term maintenance of
productivity (Brown et al, 1987). Conway
(1985) defined agricultural sustainability as
‘the ability of a system to maintain productiv-
ity in spite of a major disturbance’, while
highlighting the possibility of existing trade-
offs between the two goals of maximizing
production and maximizing (long-term)
Sustainability policy can be locally,
nationally, or internationally oriented and
may include both voluntary and regulatory
Biochar second half_BOOK.indb 793 11/11/2014 2:18:46 PM
components, while it also may require politi-
cal will in order to meet the relevant targets.
Such a framework can be regarded as based
on three pillars: (i) society; (ii) economy; and
(iii) environment. Figure 28.1 conceptualizes
these as three dimensions of sustainability
policy, integrating a hierarchical system that
consists of four levels: (i) Principles; (ii)
Approaches; (iii) Strategies; and (iv)
Sustainable systems (see Glavič and Lukman,
2007, for further explanation of the hierarchi-
cal levels). Briefly, the foundation level con-
sists of ‘principles’: fundamental concepts
that provide guidance for further work.
Principles can be mostly one-dimensional,
such as the soil information function ‘sif’ (e.g.
archaeology) that is mostly associated with
the society dimension. Other principles are
inherently three-dimensional, such as the soil
regulation function ‘srf’ and the intergenera-
tion equity argument ‘ie’ (i.e. that future gen-
erations have equal rights to natural resources
as the current generation), which are equally
relevant in building a sustainable system (top
level in Figure 28.1).
Figure 28.1 Sustainability-associated terms integrating a three-dimensional ‘sustainability policy’
framework consisting of four levels of hierarchy (adapted from Glavič and Lukman, 2007). See text
for explanation of hierarchy. rc=responsible care; sp=sustainable production; sa=sustainable
application; la=labelling; bpc=biochar production certification; sts=soil thematic strategy; bec=biochar
environmental certification; bs=biochar standard; zw=zero waste; lca=life cycle approaches; smi=soil
monitoring indicators; obd=optimum biochar dose; sif=soil information function; spf=soil production
(crop) function; ie=intergenerational equity argument; pp=precautionary principle; ep=energy
production; wm=waste management; srf=regulation function; mc=adaptation to/mitigation of climate
change; ge=geo-engineering; shf=habitat function
Biochar second half_BOOK.indb 794 11/11/2014 2:18:46 PM
Approaches (tactics) form the second
level in sustainability policy and contain a
cluster of principles focused on the same
topic. Approaches are mostly three-dimen-
sional, although some approaches are pre-
dominantly focused on one (or two)
Strategies connect different approaches
for short- and long-term environmental pro-
tection and human welfare. Environmental
strategies are designed to prevent environ-
mental degradation, for example the soil the-
matic strategy ‘sts’. Although these strategies
focus on the environment, they also include
societal and economic aspects.
Sustainable systems form the highest
level in Figure 28.1 and are comprised of a
group of interdependent and interrelated
sub-systems, forming a coherent entity and
requiring a change in thinking patterns.
Sustainable systems include ‘responsible
care’, ‘sustainable production’ and ‘sustain-
able application’. ‘Responsible care’ is a vol-
untary performance guidance scheme that
‘enables companies to go above and beyond
government requirements and the companies
must openly communicate their results to the
public […] and includes environmental man-
agement systems’ (Glavič and Lukman,
2007). The aim of ‘sustainable application’ is
‘to ensure that the basic needs of the entire
global community are met, excess consump-
tion of materials and energy is reduced and
environmental damage is avoided or reduced’
(Glavič and Lukman, 2007).
What is biochar sustainability?
With this understanding of ‘sustainable devel-
opment’, we can start to imagine what ‘bio-
char sustainability’ should involve. We can
define biochar sustainability policy as ‘a
framework comprising a set of concepts,
commitments and action plans towards opti-
mizing environmental, societal and economic
aspects of biochar production and applica-
tion, as agreed between all interested parties
(society, industry and government)’. Biochar
sustainability needs to be addressed in an
interdisciplinary and multidimensional
framework due to the cross-cutting nature of
biochar, perhaps comparable to that of biofu-
els. Further concerns would need to be
addressed in a biochar sustainability scheme
given that it is for application to soils, thus the
range of biotic and abiotic interactions across
large spatial and temporal scales in the soil
ecosystem would also need to be considered.
In fact, biochar persistence in soils (Chapter
10), when compared to traditional soil
amendments such as manures or crop resi-
dues, increases the need for understanding
how biochar will behave (interact, change)
and be subject to transport in soil and into
aquatic systems over a number of human
generations. Therefore, in essence, a biochar
sustainability framework that is adaptive and
knowledge-generated represents:
a commitment to protect soil functions,
global environmental quality and human
an obligation to meet the relevant volun-
tary or regulatory product standard spec-
ifications, as well as environmental
a dedication to communicate the relevant
information and policy in an effective
and transparent way;
a responsibility to continue improving
and updating the sustainability system in
relation to both production and applica-
tion components.
The benefits of developing a biochar sustain-
ability policy are thus manifold and reflect
environmental, social and economic gains,
perhaps firstly at the local development scale
and progressively extending to the global
scale. For instance, a biochar sustainability
Biochar second half_BOOK.indb 795 11/11/2014 2:18:46 PM
policy could potentially lead to increasing
local economic development (particularly in
rural areas), including enhanced and cost-
effective local food production and supply,
which can result in generating employment
and new businesses, facilitating effective
waste reduction and recycling strategies.
Biochar research has grown exponentially in
the last decade, along with a strong public
and industrial interest and activity. We are
moving fast towards the need for a rigorous
sustainability policy to help us prevent envi-
ronmental degradation, as well as to manage
and optimize the impacts of biochar on all
three environmental, economic and societal
Biochar sustainability criteria and indicators
Defining a set of sustainability criteria and
indicators was required for implementing an
objective, effective and transparent biofuel
sustainability policy, supply chain and use
policy. Repeating this process for biochar will
require addressing further challenges, as
extending biofuel sustainability criteria to
biochar will need to also ‘encompass the
effects on soil, any substitution of soil amend-
ments, as well as the sequestration value of
the biochar’ (Cowie et al, 2012). Currently,
sustainability criteria for biochar have not
been developed in the literature. Buchholz et
al (2009) defined 35 sustainability criteria for
bioenergy systems from a literature review,
using a survey with 137 experts to rank the 35
identified sustainability criteria according to
relevance, practicality, reliability and impor-
tance. Table 28.1 lists the top third of the cri-
teria ranked by importance and provides
examples of how these criteria may be
extended for biochar sustainability.
While such criteria themselves are not a
direct measure of sustainability performance
but rather are an area of focus, ‘sustainability
indicators’ may also be outlined to feed objec-
tive information about the status of the selected
criteria. Such indicators should meet specific
scientific, functional and feasibility require-
ments in order to be effective, including:
measurability and objectiveness: reflect-
ing the extent and direction (‘good’ or
‘bad’) of the process under assessment,
represented in standard units;
robustness and reproducibility: whose
measure is methodologically sound and
sensitivity, representation and specificity:
they should be sensitive and respond
quickly to changes in the system under
assessment, while overall integrating sys-
tems variability;
manageability and feasibility: easy and
cost-effective to handle and measure;
acceptability and comparability: should
be recognized and accepted by the rele-
vant scientific and policy communities.
What is certication?
Certifying a biochar as being produced sus-
tainably and/or by stipulating on the label
how it can be sustainably applied to soils,
requires transparent procedures and pro-
cesses. Certification can be one of the path-
ways towards achieving this, while being a
useful strategy in the implementation of a
sustainability policy. Depending on how the
certification scheme is organized, it can be an
approach, or a sub-system that employs
approaches, such as life cycle assessment,
zero waste, or contamination control (Figure
28.1). Certification has been relatively suc-
cessfully applied to wood products to pro-
mote sustainable forest management (e.g.
Biochar second half_BOOK.indb 796 11/11/2014 2:18:46 PM
Table 28.1 Sustainability criteria for bioenergy systems and proposed adaptations for sustainable biochar production and use (adapted from
Buchholz et al, 2009)
Criterion Dimension Explanation Biochar extension
Climate change
Environment GHG balance of system covering CO2, CH4, O3, N2O,
Sequestered C, N2O & CH4 emissions, black carbon aerosols, water
holding capacity, land surface albedo change from bare soil and
vegetation (expressed as radiative forcing) (Chapters 10, 16, 17, 24,
Energy balance Environment
and economy
Conversion efciencies, energy return on investment,
energy return per unit area
Production, storage, transport, handling and application (Chapters 3,
6, 26, 29)
Soil protection Environment
and society
Impacts on soil fertility, e.g. changes in nutrient cycling,
rooting depth, organic matter, water holding capacity,
Include effects of range of biochar types on range of soil types for soil
functions and/or threat indicators: e.g. soil biodiversity, compaction,
salinization, sealing, contamination, etc. (Chapters 11–23)
Participation Society Inclusion of stakeholders in decision making; facilitation
of self-determination of stakeholders
Include agronomists, landowners, waste treatment and recycling
companies (across spatial scales) (Chapters 29 and 30)
and society
Surface and groundwater impacts, riparian buffers,
irrigation and cooling cycles and waste water
Include environmental risk assessment based on analytical and
biological criteria relevant to surface run off and groundwater;
reduced pesticide and nutrient leaching (Chapters 11, 19)
Natural resource
Environment Efcient use of resources at all stages of the system Trade-offs between resources (Chapters 29 and 30)
Economy Cost-efciency incl. start-up costs, internal rate of return,
net present value, payback period
Economic trade-off between bioenergy and biochar (Chapters
Compliance with
Society Complying with all applicable laws and internal regula-
tions like certication principles, countering bribery
Environment Safeguarding protected, threatened, representative, or
other valuable ecosystems (e.g. forests), protecting
internal energy uxes/metabolism
Soil biodiversity; aquatic and marine ecosystems (Chapters 11, 13,
Monitoring of
Society Monitoring systems in place for all criteria (e.g. leakage
or additionality in GHG accounting)
Harmonized methods for monitoring biochar in soils; audit scheme
(Chapters 24, 27)
Food security Society Enough land locally available for food production
including agricultural set aside land, preference of
marginal sites for energy crops
Effect on crop yield within current agricultural area (Chapter 12)
Environment Disposal of ashes, sewage, hazardous/contaminated solid
and liquid material
Use of waste materials as feedstocks; disposal of tar and bio-oil
(Chapter 28)
Biochar second half_BOOK.indb 797 11/11/2014 2:18:46 PM
Cobut et al, 2013) and is being developed for
biofuels (e.g. Scarlat and Dallemand, 2011).
Many types of certification exist, ranging
from voluntary to compulsory, from self-
determined to externally audited, from sim-
ple classification to full life cycle assessment,
and from those focused on a single subject to
integrating a range of subjects. Each type has
its advantages and disadvantages, some of
which are discussed in the next section.
Sustainable biochar certication
As previously suggested, sustainable biochar
systems depend on both ‘sustainable produc-
tion’ and ‘sustainable application’ (see also
the top hierarchical level in Figure 28.1) and
is not an ‘either/or proposal’. These are two
necessary halves of the sustainability equa-
tion, meaning that a sustainable biochar pol-
icy is only possible when both are adequately
established. Since in this book biochar is
defined functionally as ‘intended for use as a
soil application or broader for environmental
management’ (Chapter 1), ‘sustainable appli-
cation’ then can be interpreted as to include
environmental management. Therefore, in
addition to sustainable product standardiza-
tion or certification, a sustainability label also
needs to include the concept of ‘sustainable
application’. Alongside biochar’s heterogene-
ity, soils have been shown to exhibit substan-
tial variation in properties at spatial and
temporal scales relevant to biochar applica-
tion. This implies that sustainable biochar
application to soil would need to explicitly
consider spatial heterogeneity through cate-
gorization from field to regional scales while
accounting for the relevant socio-economic
context, including aspects of feedstock avail-
ability, competition for resources, land use,
agricultural practices and GHG emissions.
Certification is normally communicated to
the consumer by means of a stamp or an (eco)
label, which is awarded upon verification that
the product meets the relevant criteria. This
would probably be enough for the product cer-
tification component but would not add infor-
mation on the environmental certification,
since it discards any spatial and temporal envi-
ronmental variability. To overcome this,
Verheijen et al (2012) argued for biochar label-
ling to ‘extend beyond a technical description
and labelling of the biomass feedstock and bio-
char material to also include the environmental
and socioeconomic context relevant to the site
where biochar would be applied to soils as well
as to where the feedstock was grown’. Ideally,
such a comprehensive labelling system would
provide measured environmental data on
pre-established parameters, or a combination
thereof, through life cycle assessment, set and
verified by an impartial third party, such as
a non-governmental organization (NGO),
Environment Agency, etc. As a first approach
in this context, the authors suggested the inclu-
sion of the following information: ‘biochar with
properties A, B, C (including concentrations of
contaminants), which makes it appropriate for
ecotopes with properties D, E, F to grow crop
types G and H, but not crop type I, at biochar
application rates of J (Mg ha-1 per year) every
K years, to L (Mg ha-1 per year) every M years,
up to a maximum biochar loading capacity of
N (g kg-1)’. One perceived drawback associ-
ated with such a labelling system is that,
whereas the product certification component is
easily verifiable, the environmental certification
component is likely more difficult to verify.
This discussion deserves full attention and
communication between all interested parties
and suggests that accompanying the imple-
mentation of an effective biochar certification
system is the awareness and adequate training
of the various biochar players.
Biochar second half_BOOK.indb 798 11/11/2014 2:18:46 PM
Biochar production certication
– a work in progress
Three nascent biochar certification pro-
grammes and standards exist today: (i) stand-
ardized product definition and product
testing guidelines for biochar that is used in
soil (aka IBI Standards; IBI, 2013, which pro-
vided grounds for the IBI Biochar Certification
Programme (IBI, 2013); (ii) ‘European
Biochar Certificate’ (EBC, 2012) (aka EBC
Standards); and (iii) the ‘British Biochar
Quality Mandate’ (BBF, 2013) (aka BQM
Standards). Common aims between such
schemes (Table 28.2) include: (i) providing
an indicator of quality and safety with respect
to basic product specifications for use as a soil
amendment, being based on the latest rele-
vant research and practice; (ii) driving expan-
sion of this industry and product
commercialization through providing the
necessary quality assurances for both users
and producers; and (iii) providing state-of-
the-art information as a sound basis for future
legislative or regulatory approaches, while
requiring that the existing relevant regional or
national environmental quality criteria are
met during production.
Table 28.2 Comparison of existing biochar production standards/certification schemes.
1 The IBI Biochar Standards relate to the physicochemical properties of biochar only and do not
prescribe production methods or specific feedstocks, nor do they provide limits or terms for defining the
sustainability and/or GHG mitigation potential of a biochar material.
2 The BQM was still to be finalized at the time this book went to press
Sustainable procurement
of feedstock
Not controlled Based upon Life Cycle
methods in the EU
Renewable Energy
Directive and sustainable
timber procurement
guidelines used by UK
Feedstock positive list,
controlled use of energy
crops, limited distance for
transportation to the
production site
Feedstock composition Self-declaration, change of
composition results in
new lot of biochar,
content of contaminants
<2%, upon manufac-
turer’s responsibility
Self-declaration, change of
composition results in
new lot of biochar
Controlled declaration,
change of composition
results in new lot of biochar
Emissions during biochar
Syngas combustion has to
comply with local and/or
regional and/or national
emission thresholds
Syngas produced during
the pyrolysis has to be
either trapped and used,
or combusted efciently,
emissions must comply
with local and national
Syngas produced during the
pyrolysis has to be trapped.
Syngas combustion has to
comply with national
emission thresholds
Biochar second half_BOOK.indb 799 11/11/2014 2:18:46 PM
Table 28.2 continued
Energy and GHG balance
for production
Not controlled Based on the EU
Renewable Energy
Directive, requiring a 60%
reduction in net GHG
emissions compared to
the baseline fossil fuel
case across the product
life cycle (for >4t biochar
production per day)
Biomass pyrolysis must take
place in an energy-
autonomous process. No
fossil fuels are permitted for
reactor heating
Control of dust emission
and ignition hazard
Not controlled Must comply with UK
Health & Safety Law
Humidity of stored biochar
must be >30%
Product denition (C,
H/C, nutrient content,
ash, EC, pH, particle size
distribution, specic
surface, VOCs, available
H/Corg < 0.7; Corg ≥
60%/30%/10%; other
values to be declared,
some only in category 2
resp. 3
Still to be nalized H/Corg < 0.7; Corg ≥ 50%;
other values to be declared,
some only in premium
Control of heavy metal
(required in category
 
Control of organic
content (PAHs, PCBs,
Furans, Dioxins)
(required in category
 
Independent lab-analysis,
control of analytical
methods and standard
(self-declaration of
  (only accredited labs)
Record of production
reference and complete
traceability of product
Independent on-site
production control
None Left to regulatory agency
Transparent product
declaration for buyers
On package Still to be nalized On delivery slip or annexed
to invoice
Handling advice and
health and safety warning
Annexed delivery
document for appropriate
shipping, handling and
storage procedures
Still to be nalized Annexed delivery document
for appropriate shipping,
handling and storage
Biochar second half_BOOK.indb 800 11/11/2014 2:18:46 PM
Biochar production technology is cur-
rently developing fast, with more than 500
research projects worldwide looking into bio-
char properties, with increasing awareness of
the way these determine aspects of biochar
environmental behaviour, mobility and fate,
including interactions with soil mineral,
organic and biological components. Every
year new manufacturers of pyrolysis equip-
ment enter the market and the areas in which
biochar and biochar products are used are
steadily and rapidly growing. Usage ranges
from application to soils individually, to com-
bined soil applications in the form of compost
additives, carrier for fertilizers, manure treat-
ment, silage additives, or feed additives.
Considering that both biochar properties and
its overall environmental footprint are inter-
dependent on processing conditions and
feedstock type, a framework that secures
basic material quality control can positively
impact on increasing sustainability with
regard to production technology.
Following multidisciplinary research and
field trials, the understanding of the biological
and physicochemical processes involved in
the production and use of biochar has
improved. However, it should be acknowl-
edged that most studies have investigated the
effects of deliberate biochar application to
soil only in the short term (except for char-
coal or fire-derived char that may occur in
soils of former charcoal producing sites or
wildfire-affected areas), with a large number
of studies investigating at the sub-annual
scale and the longest studies only running for
up to 10 years (see Chapter 12).
Users of biochar and biochar-based
products should benefit from a fully transpar-
ent and verifiable monitoring and policing of
compliance to the reference specifications,
for biochar production. While the EBC prod-
uct certification scheme has stepped forward
from essentially self-reporting to include an
independent monitoring/policing of compli-
ance component, it appears timely to discuss
the prospects of more comprehensive frame-
works that match an expanding industry and
Biochar production standardization/cer-
tification schemes promote optimizing the
production and commercialization sector by
highlighting the need for developing a prod-
uct that holds a minimum set of characteris-
tics to ensure agronomic and environmental
performance, including guidelines against
misuse. It is certainly a prerequisite that bio-
chars have to fulfil a set of basic quality speci-
fications (e.g. C content, porosity, pH,
contents of metals and polycyclic hydrocar-
bons contents) so that application to soil sus-
tains the desirable effects, while minimizing
negative effects. As biochar can remain in
soils for decades to millennia (Chapter 10),
alongside the practical irreversibility of large-
scale implementation to soil and sediments,
such standardization and certification
schemes are useful approaches towards sus-
tainable biochar systems. For the user, the
result is an increased level of confidence on
the material performance, although cases
where negative effects may outweigh positive
may still occur, if adequate matching between
biochar and soil properties is not achieved.
Ultimately, there is also potential for such
schemes to provide sound basis for policy
development. Biochar is a class of material
for which an adequate legal framework is only
now being sought. While in Europe, a possi-
ble integration under the REACH framework
is still being disputed, governmental adminis-
trations can benefit from a sophisticated
product standards to help define if/where bio-
char fits existing (non-mutually exclusive)
legal ordinances, which may include aspects
of that of fertilizers and organic amendments,
as currently taking shape in the U.S.
Moreover, those feedstocks for biochar pro-
duction that are considered waste materials
may not be allowed to be recycled for agro-
Biochar second half_BOOK.indb 801 11/11/2014 2:18:46 PM
nomic uses. It has thus to be shown, through
production and quality standards, that bio-
char is not a waste product but a manufac-
tured quality product, contributing to a zero
waste society.
Is it then possible to enhance such
schemes (or develop new ones) in order to
maximize their potential contribution to
developing truly sustainable biochar systems?
One obvious limitation of the current biochar
standards/certificates is that they rely on gen-
eralization and underestimate the influence of
biochar–soil–crop/biota interactions in deter-
mining such sustainability. One explanation
for this may be the very recent divergence
between biochar research and the production
sector. Clearly, it is vital that any certification
programme that is implemented is built on
sound objective science in order to maximize
confidence in such certification schemes.
While the current scientific level of under-
standing of the full range of environmental
implications, both spatially and temporally, is
slowly expanding, it is also important that
such programmes are adaptive in order to
accommodate newly generated knowledge
and development. This would perhaps
require regular revisions and guideline
updates, as well as adjustment of specification
thresholds and elimination or re-introduction
of test methods, as necessary. The specific
mechanisms of how the latest scientific evi-
dence should be interpreted for updating and
fully documented standards and certification
schemes would need careful consideration, to
ensure the most comprehensive, unbiased
and transparent outcome.
A sustainable biochar system, consisting
of sustainable production as well as sustain-
able application and regulated by a sustaina-
bility policy, also requires verifiable
monitoring and policing of compliance to the
reference specifications (rather than a basic
self-reporting procedure). In the case of a
compulsory framework, certification would
then be upgraded from a ‘strategy’ to a ‘sys-
tem’ level at the top of the sustainability pyra-
mid (see Figure 28.1). As a sustainable
system comprising a set of interdependent
and interrelated strategies, such certification
schemes would require a new level of organi-
zation and coherency, as well as a change in
thinking patterns for enhanced environmen-
tal protection and human welfare. Compliance
to standard specifications alongside on- and
off-site control by an independent and
accredited third party, such as those contem-
plated by the EBC, is one step forward in this
Sustainable biochar application
certication – a work in its
The development of a truly sustainable bio-
char application certification (a ‘strategy’ in
Figure 28.1) requires an integrative strategy
that may use several approaches (one level
down in Figure 28.1, for example: soil moni-
toring indicators, the concept of ‘optimum
biochar dose’, life cycle approaches, etc.).
The latter two are discussed in more detail
Optimum Biochar Dose (OBD)
Currently, a lot of studies are looking at the
effects of biochar application to soil on vari-
ous ecosystem processes, functions and ser-
vices. Such experiments use a range of soil
and biochar characteristics, as well as appli-
cation rates from 1t ha-1 to in excess of 150t
ha-1. A quantitative meta-analysis of crop
productivity response to different applica-
tion rates (Jeffery et al, 2011) suggests that
increased biochar doses generally lead to
increased crop productivity responses.
However, some work has shown that crop
responses may increase with biochar appli-
cation rates to a point, and then either level
off, or lead to a reduction in response to fur-
Biochar second half_BOOK.indb 802 11/11/2014 2:18:46 PM
ther biochar dose increases. In this respect,
the existence of such a dose-response pat-
tern for biochar is not that dissimilar to those
for any traditional soil amendment and man-
agement practices, including fertilizers,
compost, lime, etc. For example, Mia et al
(2014) found that grass, clover and plantain
all increased in productivity with biochar
applied at 1t ha-1 and increased further at 10t
ha-1. However, there was no statistical sig-
nificance in productivity levels between bio-
char and the control (i.e. no biochar
application) treatments at 50t ha-1, suggest-
ing that negative balanced out the positive
effects that were evident at lower application
rates. Further, a negative crop productivity
response was observed in all three crop types
investigated at biochar concentrations in soil
of 120t ha-1. This strongly suggests that in
the studied system, there would be a specific
biochar application rate that would corre-
spond to optimal crop productivity levels
and that can be referred to as specific bio-
char dose–effect (BDE) of that system.
Importantly, such a pattern is likely to be a
function of any given biochar–soil–crop–
climate combination and highlights the need
for a priori assessment of such system char-
acteristics before biochar application should
be considered. Such dependency as an
inherent property of the system is not found
in the traditional fertilizer literature.
Furthermore, Graber et al (2012) found
biochars with high specific surface areas to
decrease herbicide efficacy and suggested
that weed control needs may be best served
by low specific surface area biochars. The
optimum biochar dose (OBD) should there-
fore be further extended to comprise biochar
characteristics (quality), rather than solely
application rate (quantity), as both aspects
are interdependent (Chapter 8). In addition,
repeat applications of smaller amounts are
likely to require different biochar qualities
than a single large application.
The concept of the optimum biochar dose
(OBD), as suggested here, is one that pro-
gressed from a universal and constant prop-
erty of a given biochar system to one that is
specific to all dimensions of the biochar–soil–
crop–climate setting. It has further utility as
it can be applied in different ways depending
on the desired goals. For example, referring
back to the experiment of Mia et al (2014),
for maximizing grass, clover and plantain
yield, the target biochar dose is apparently
somewhere between 10 and 50t ha-1 for the
studied biochar–soil–crop–climate combina-
tion. However, if carbon (C) sequestration is
the goal, then the experiment demonstrated
that it is possible to add biochar at 50t ha-1 and
so maximize the amount of C input into the soil
without experiencing negative effects in terms
of the selected plant productivity. Regarding
suppression of soil-borne plant diseases, Graber
et al (2014) found ‘hump-shaped’ relationships
with biochar concentration (soil function B in
Figure 28.2) with significant effects only at
intermediate biochar concentrations. In reality,
it is likely that biochar application will be
expected to have multiple goals. The OBD will
then be a trade-off between the quantity and
quality of the individual goals’ target biochar
doses (see Jeffery et al [2011] for a discussion of
biochar trade-offs).
The conceptual diagram in Figure 28.2
highlights different biochar dose–effect sce-
narios in relation to soil functions (A-D) and
is one way of representing the concept of
OBD for any specific biochar–soil–crop–cli-
mate combination. For example, the OBD for
scenario 1 corresponds to an optimal soil
function A, as well as to benefits to functions
B and C, but it is the furthest that one can go
without compromising function D. However,
should one consider the loss of function D up
to a certain extent acceptable, one may opt
for OBD scenario 2, reflecting in further
enhanced B and C functions, with only mar-
ginal impact on A, and so on.
Biochar second half_BOOK.indb 803 11/11/2014 2:18:46 PM
Figure 28.2 Conceptual representation of the Optimum Biochar Dose for any specific biochar–soil–
crop–climate combination. Solid lines are response curves for individual soil functions or sub-functions
(A-D). The dashed lines are potential optimal OBDs (1–4), which may have to include value
judgments. For example: is a 50 per cent decrease in soil sub-function D offset by a 30 per cent and a
50 per cent increase in soil sub-functions B and C? Dose-effect curves for soil (sub)functions may look
significantly different for biochar ‘Y’ or ‘Z’, etc.
As a concept, the OBD of a specific biochar–
soil–crop–climate combination highlights the
importance of allowing effective develop-
ment of biochar application certification as
introduced in this chapter. The high level of
inherent heterogeneity that it accounts for,
both at the level of physicochemical proper-
ties of the selected biochar and application
site, but also of the organomineral as well as
biological interactions that are likely to occur,
means that the OBD is likely to be also influ-
enced by soil type, climate and land use, as
proposed by Verheijen et al (2012). It is rea-
sonable, therefore, to expect that sustainable
biochar application for any given biochar–
soil–crop–climate combination, communi-
cated to the user through labelling, should be
informative of the maximum rate at which
that specific biochar may be applied to speci-
fied categorization of soil–crop–climate com-
binations. Whereas the current level of
scientific understanding might still be low
regarding the exact nature and extent of such
environmental interactions, we are slowly but
steadily moving towards filling such knowl-
edge gaps. This also implies that biochar
manufacturers would be encouraged to both
take responsibility for their product quality
standards and work closely with academia to
promote independent research on the envi-
ronmental effects and mechanisms when
applied to soils. Greater synergism at this
level can be a path for environmental sustain-
ability certification, where responsible manu-
Biochar second half_BOOK.indb 804 11/11/2014 2:18:47 PM
facturers seeking to meet standard product
specifications are offered adequate practical
support, scientific guidance and training
throughout the production and commerciali-
zation chains.
One could argue for the individualization
of both production and application certifica-
tion components, in order to overcome
potential drawbacks of joint certification sys-
tems. For instance, Pacini et al (2013) identi-
fied a possible bottleneck where producers
and users in developing countries may be
challenged in their capacity to cope with
requirements of sustainability certification.
Pacini et al (2013) argued that smallholders
and small producers in developing countries
should receive adequate support, which may
include technical and financial aid to meet
sustainability certification. Issues such as this
are fairly easily raised and allude to the aspect
of the utility of any implemented certification
system, underlining the necessity to include
all relevant environmental, economic and
sociocultural parameters in developing a
practical and effective biochar certification
framework. One could also argue that indus-
try has an inherent interest in funding inde-
pendent research on environmental effects,
and side-effects, of biochar in soils and their
associated mechanisms, and for the environ-
mental certification to be an integral part of
any biochar label. If biochar starts to be
applied indiscriminately, cases of ‘no effect’,
or even negative effects, on specific soil func-
tions are likely, which would have the poten-
tial for damaging perceptions and reduced
interest from consumers.
Life cycle assessment (LCA)
Current efforts to mitigate environmental
damage, such as from climate change and
ecosystem/biodiversity impacts, through cer-
tification schemes (e.g. labels of carbon foot-
prints) emphasize the value of LCA as a
support tool for the calculation of robust and
meaningful measurements of the environ-
mental impacts associated with biochar. LCA
practice is standardized in the ISO 14040-
14044 series (ISO, 2006a, b). Further guide-
lines exist, such as the PAS2050 (BSI, 2011),
the GHG Protocol, the ILCD handbook
(European Commission, 2010a, b) and the
ISO 14067 (2013), most of which focus on
carbon footprinting.
LCA can be used to estimate the net
energy, climate change impacts and impacts
on ecosystem services and biodiversity asso-
ciated with biochar production, transport and
application to soils. Of the criteria identified
in Table 28.1, current LCA methods are
robust enough for quantification, with the
exceptions of participation, microeconomic
sustainability, compliance with laws, moni-
toring of criteria performance and food secu-
rity; these fall under the society dimension,
which is commonly excluded from LCA.
However, these criteria can still be analysed
with a life cycle approach to benchmark envi-
ronmental (and economic and social) impacts
along the life cycle system for the production
of a given quantity of biochar.
A comprehensive and systematic assess-
ment will necessarily cover a wide range of
environmental impacts, such as those recom-
mended in the ILCD handbook (European
Commission, 2010b) and sustainability crite-
ria that have already been developed for bio-
energy, but still need development for biochar
(see Table 28.1). As previously mentioned,
compared to other soil organic matter amend-
ments, e.g. composts, manures or crop resi-
dues, biochar has a very long residence time
in the environment. Therefore, a methodol-
ogy for measuring the impact on climate
change that takes into account the time
period in which C is stored is necessary (e.g.
Brandão and Levasseur, 2011; Brandão et al,
New Life Cycle Impact Assessment
methods of land use impacts on ecosystem
Biochar second half_BOOK.indb 805 11/11/2014 2:18:47 PM
services and biodiversity have been published
in the recent special issue of the International
Journal of Life Cycle Assessment on: carbon
sequestration potential (Müller-Wenk and
Brandão, 2010); biotic production potential
(Brandão and Milà i Canals, 2013); freshwa-
ter regulation potential (Saad et al, 2013);
erosion regulation potential (Saad et al,
2013); water purification potential (Saad et
al, 2013); and biodiversity (de Baan et al,
2013). These methods are relevant to the
assessment and associated certification of
biochar insofar as the biochar’s potential
impacts on climate change, various ecosys-
tem services and biodiversity can be quanti-
fied. Additional ecosystem services (e.g.
recreation) have not been included, as meth-
ods to model these are still lacking and, as far
as we know, are not being developed yet.
The environmental load of biochar on
climate and soil depends on the different
feedstocks and production conditions, which
directly control the physicochemical charac-
teristics of the biochar. Dedicated feedstocks
could be purposefully grown for biochar pro-
duction. Dedicated biochar feedstock crops
have land requirements and, thus, compete
with other crops for land. Conversely, bio-
char production from organic wastes does
not compete for land with other uses and acts
as a waste management strategy, in addition
to the functions of climate change mitigation,
soil improvement and energy production.
However, some organic wastes, for example
crop residues, would have been incorporated
in the soil where they would have provided
functions such as soil tilth, fertility, erosion,
and as such compete with biochar regarding
the provision of ecosystem services.
Where feedstock production leads to
competition for land, increased demand for
crops can be met in three ways: land intensi-
fication, land expansion or crop displace-
ment. Land expansion for growing crops as
biochar feedstocks (e.g. onto marginal land)
have direct land use change impacts. Crop
displacements incur indirect land use change
impacts if the displaced crop is grown else-
where. The impact may be of significant
magnitude: for agricultural products, the
release of CO2 associated to land use change
can be similar to that of the rest of the life
cycle (e.g. Schmidt and Dalgaard, 2012).
ExamplEs of lCas appliEd to bioChar
Well-established LCA studies and methods
are lacking for the purpose of systematically
quantifying a broad range of impacts from
biochar. Indeed, despite the potential of
LCAs in determining the relative benefits or
negative effects of biochar, few life cycle
studies on biochar have been conducted.
However, the number is increasing steadily,
from 1 in 2008, 1 in 2009, 2 in 2010, 2 in
2011, 4 in 2012 and 9 in 2013 at the time of
writing. Furthermore, the benefits related to
the storage of C and to the improvement of
soil have been included in inconsistent ways
in terms of how the fertility and climate
impacts were considered. Some studies only
considered one and not the other, and even
the way it is considered is different across
studies. To address these requires research
on the issues of C storage and on soil improve-
ment of incorporating biochar compared to
incorporating the unpyrolyzed feedstock,
particularly how these can be robustly taken
into account in LCA to quantify the environ-
mental benefits, and trade-offs, of biochar.
The few studies that have so far been
conducted (e.g. Gaunt and Lehmann, 2008;
Gaunt and Cowie, 2009; Roberts et al, 2010)
suggest that it is more efficient, in terms of C
mitigation, to produce biochar from biomass
rather than replacing conventional sources of
electricity and/or heat from burning that bio-
mass. Converting biomass to biochar, there-
fore, may present more potential for C-saving
than biomass and biofuels because, in addi-
tion to displacing fossil fuels by generating
Biochar second half_BOOK.indb 806 11/11/2014 2:18:47 PM
heat, power and transport fuels, it stores C
which has been removed from the atmos-
phere. It needs to be noted, however, that
these few studies do not represent all biochar
systems and different outcomes for other
conditions are possible.
In addition, these studies suggest that the
net life cycle C sequestration ability of bio-
char is highly dependent on the feedstocks
and on the conversion processes adopted.
The following parameters are thought to be
of particular importance and need to be fur-
ther investigated: C storage, benefits of soil
improvers, crop yield, reference land use, ref-
erence fossil-fuel energy system, plant effi-
ciency and net energy yield, net C balance
relative to alternatives, and the specific appli-
cation of the biochar.
In order to ascertain the environmental
gains and losses of adopting biochar, it is nec-
essary to quantify and compare the life cycle
impacts on soil and climate of producing bio-
char from different feedstocks, addressing in
particular methodological gaps, such as the
methodology for measuring the impact on
climate change that takes into account the
time period in which C is stored (see for
example Woolf et al, 2010). New methods
may need to be developed and applied for
assessing and comparing the environmental
benefits and trade-offs of the different feed-
stocks for the production of biochar in LCA
and its use. The recommendations of the
International Reference Life Cycle Data
System (ILCD) for land use modelling and
impacts on climate and ecosystems can be
used for this purpose. In particular, there is a
need to address the topics of C storage and of
inclusion of soil improvement benefits in the
LCA framework. In addition, dynamic mod-
els, such as consequential LCA, may provide
a means of dealing with feedbacks over time.
The following issues and sources of
uncertainty are to be given particular atten-
tion in a robust assessment framework:
Accounting for impacts of biochar on soil
organic matter dynamics
Time horizons
Spatial scales
Environmental effects of biochar as a soil
State-of-the-art uncertainty analysis in
order to increase understanding of the
significance of uncertainty (e.g. with
Monte-Carlo analysis)
State-of-the-art risk assessment in order
to increase understanding of the impacts
of scaling-up this technology (see e.g.
Downie et al, 2012).
The main way in which LCA can support the
certification of biochar is by quantifying and
comparing the life cycle impacts on soil, cli-
mate and ecosystem services of producing
biochar from different feedstocks, and com-
paring it to amending soils with the unpyro-
lyzed feedstocks. The relevance of this topic
is high due to the current efforts to mitigate
climate change and ecosystem impacts, and
the associated need to measure these, so that
claims can be validated and verified. This is a
new area where very few LCAs exist.
Conclusions and outlook
A sustainable biochar system requires sus-
tainable biochar production as well as sus-
tainable biochar application, possibly
certified individually but brought together in
a label, to support the development of an
effective sustainability policy. While biochar
production and product certification is in
progress, biochar application certification is
Biochar second half_BOOK.indb 807 11/11/2014 2:18:47 PM
a concept in its infancy with developmental
challenges due to: (i) trade-offs between soil
functions; (ii) a much longer time horizon
than traditional soil amendments; and (iii)
limited mechanistic understanding regard-
ing the nature and extent of effects relevant
to specific biochars and soil–crop–climate
combinations. Integrative strategies are the
most promising way forward, such as the
‘optimum biochar dose (OBD)’ and life
cycle approaches, alongside synergistic pro-
grammes where responsible manufacturers
and users are offered adequate support, sci-
entific guidance and training throughout the
production, commercialization and con-
sumption chains. It is clear that a consider-
able effort is required to achieve such a
comprehensive and practical certification
system, but sustainable biochar production
and sustainable environmental biochar
application are two sides of the same coin
(sustainable system). One cannot succeed
without the other.
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... There are also contrasting observations between laboratory and field trials (Tammeorg et al., 2014;Gruss et al., 2019) as well as the potential influence of land use and soil management (Cordovil et al., 2019;Briones et al., 2020) and biochar ageing processes over time (Hammes and Schmidt, 2009). Together, these highlight the need for a case-by-case evaluation of soil-biochar-climate and management combinations (Verheijen et al., 2012(Verheijen et al., , 2015(Verheijen et al., , 2019a. In this context, bioassays are valuable tools in assessing how edaphic organisms may be impacted upon exposure to such heterogenous matrices, via the watersoluble fraction (Hund-Rinke and Kördel, 2003;Jonker et al., 2005;Rocha et al., 2011;van Gestel, 2012). ...
There is an urge for rapid, cost-effective and ecologically representative tools that inform on possible changes in habitat function of biochar-amended soils, at representative spatial and temporal scales. We employed a battery of invertebrate avoidance behaviour tests to screen and biomonitor a vineyard soil amended with a premium grade mixed-wood chip biochar (applied alone or mixed with compost) at plot-scale, at 4 or 40 t ha − 1 , over 12 months. The assays combined representative organisms with complementary ecological functions in agro-ecosystems, i.e. earthworms (Eisenia andrei), collembolans (Folsomia candida) and isopods (Porcellionides prui-nosus). In all treatments, soil habitat function was within the recommended limits for the selected invertebrate groups, by the corresponding soil quality guideline or protocol. However, collembolans exhibited significant avoidance behaviour from 6-month aged biochar treatments, coinciding with a strong peak in soil electrical conductivity (EC), suggestive of osmotic stress. Earthworms responded less sensitively than collembolans, with isopods being the least sensitive group to biochar amendments. Further, there was a preference by isopods for freshly-amended soil, whereas earthworms and collembolans preferred 12-month aged biochar amended soil, both of which can be explained, at least partly, by nutrient inputs. Overall, results show that invertebrate avoidance behaviour, based on multiple test groups, can be used to screen and complement site-specific biochar risk assessment strategies, for early decision-making and management. For screening batteries of mixed wood biochars, this study further supports the combined use of collembolans and earthworms, with isopods as a complementary test group.
... (Figure 1) Charcoal is from woody biomass and thermally converted under less controlled pyrolysis conditions (often in a pile or a pit in the ground) than biochar, which can be from any sustainably sourced biomass and under more controlled pyrolysis conditions because it has to meet the quality criteria of the certification. For example, IBI (International Biochar Initiative) Biochar Certification Program (IBI, 2015), and European Biochar Certificate (EBC, 2012) are biochar certification programs and standards which they have common aims for providing an indicator of quality and safety of biochar for use as a soil amendment, also through the necessary quality assurances for both users and producers; and providing state-of-the-art information as a sound basis for future legislative or regulatory approaches (Verheijen et al., 2015). It can be used to improve agriculture and the environment in several ways, and its persistence in soil and nutrient retention properties make it a potential soil amendment. ...
Technical Report
Full-text available
The work presented, was to review the scientific literature for evidence of how biochar can be used to adapt soils to the challenges posed by climate change, specifically for three important land uses in Portugal, i.e. forest plantations, permanent crops, and grasslands.
... biochar characteristics), as well as the independent variables (i.e. soils, climates, land use and land management; Verheijen et al. 2012Verheijen et al. , 2015. The first step in developing the LOSU for biochar is to determine how representative the knowledge base is regarding production and environmental application. ...
Full-text available
A representativeness survey of existing European Biochar field experiments within the Biochar COST Action TD1107 was conducted to gather key information for setting up future experiments and collaborations, and to minimise duplication of efforts amongst European researchers. Woody feedstock biochar, applied without organic or inorganic fertiliser appears over-represented compared to other categories, especially considering the availability of crop residues, manures, and other organic waste streams and the efforts towards achieving a zero waste economy. Fertile arable soils were also over-represented while shallow unfertile soils were under-represented. Many of the latter are likely in agroforestry or forest plantation land use. The most studied theme was crop production. However, other themes that can provide evidence of mechanisms, as well as potential undesired side-effects, were relatively well represented. Biochar use for soil contamination remediation was the least represented theme; further work is needed to identify which specific contaminants, or mixtures of contaminants, have the potential for remediation by different biochars.
Soil amendment with biochar is being considered as a strategy for improving available soil water and nutrient content and, thereby, plant performance. Our aim was to investigate whether physiological, biochemical and morphological responses of Eucalyptus globulus to biochar amendment were dependent on watering regime. We conducted a randomized, 6-week greenhouse experiment with 5-month old eucalypt rooted cuttings in sandy soil, with the factors: ‘biochar application rate’ (0% and 4%, ww−1), ‘watering regime’ (20% and 80% of maximum soil water holding capacity; MWHC) and ‘fertilization’ (with and without). Increased plant physiological responses to biochar were the most pronounced under water-limited and unfertilized conditions, with a significant increase in leaf water use efficiency (WUE; + 40%), net photosynthetic rate (+ 60%) and plant survival rate (+ 33%), while plant biomass was unchanged. Under water-limited and fertilized conditions, we found no significant biochar effects, except for a small reduction in photochemical and non-photochemical quenching (qP and NPQ, respectively). Under well-watered and fertilized conditions, biochar did not affect leaf WUE or total biomass but reduced the number of branches (− 30%) and photosynthetic rate (− 24%). Finally, under well-watered and unfertilized conditions, biochar was associated with apical leaf deformation, indicating potential micronutrient deficiency, as well as an increase in total soluble sugars and a decrease in stomatal conductance. While the observed benefits suggest that a woody biochar may be advantageous in managing un-irrigated eucalypt plantations, particularly during the planting period, the occurrence of trade-offs urges for long-term studies that account for different dynamic watering regimes, biochar types and application rates, as well as soil–plant-biochar-climate combinations.
High severity wildfires cause a drastic alteration of soil carbon cycling – both oxidising and thermally altering soil organic matter (SOM) - and usually are followed by strong runoff and erosion events. To restore wildfire-degraded soils, SOM needs to be rebuilt while soil erosion is prevented. Post-fire straw mulching has been shown to mitigate soil erosion by providing a protective cover against rainsplash. However, SOM takes many decades or centuries to rebuilt naturally. Biochar, co-applied with straw to the soil surface can replace the SOM of the O-horizon, while the stabilised soil – by straw mulching – may gain in SOM naturally and by downward movement of biochar. We conducted a field study to test if straw-only and straw-biochar co-application could restore soils degraded by wildfire in one high burn severity (HBS) and one moderate burn severity (MBS) study area in southern Portugal and Spain, respectively, by monitoring erosion and SOM for the most intense rainfall period of the first post-fire year. Burned sites were characterized for soil and sediment physical properties, TOC content, SOM quality by thermogravimetry (DTG) and nuclear magnetic resonance (NMR ¹³C) spectroscopy. Straw-biochar mulching significantly reduced soil erosion by 76% and 65% in the HBS and MBS sites, respectively, in both cases similar to the erosion reduction by straw-only mulching. DTG and NMR ¹³C indicated that a relatively small proportion of the biochar eroded, i.e. 0.7%, indicating that co-application of straw with biochar may help restore the SOC lost in the wildfire in the medium term. The amount of SOM eroded was lower with straw-biochar mulching than in the untreated plots for both study areas. Straw-biochar mulching mitigates erosion of wildfire-degraded soils under extreme rainfall, while a relatively small proportion of the biochar is lost by erosion. Future studies need to monitor medium term effects.
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Including the work of thirty four authors through thirteen chapters, this book provides a balanced critique of a range of international sustainability certification schemes across nine agricultural and natural resource industries. Certification schemes set standards through intra-market private and multi-stakeholder mechanisms. While third party verification is often compulsory, they are regulated voluntarily rather than legislatively. This book examines the intricacies of certification schemes and the issues they seek to address and provides the context within which each scheme operates. While a distinction between sustainability certifications and extra-market or intra-business codes of conducts is made, the book also demonstrates how they often work towards similar sustainability objectives. Each chapter highlights a different sector, including animal welfare, biodiversity, biofuels, coffee, fisheries, flowers, forest management and mining, with the contributions offering interdisciplinary perspectives and utilising a wide range of methodologies. The realities, achievements and challenges faced by varying certification schemes are discussed, identifying common outcomes and findings and concluding with recommendations for future practice and research. The book is aimed at advanced students, researchers and professionals in agribusiness, natural resource economics, sustainability assessment and corporate social responsibility.
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The purpose of this review is to examine how biochar additions to soil can affect plant diseases caused by soilborne pathogens, with particular attention to mechanisms and knowledge gaps. Until now, biochar soil amendment has been reported to affect the progress of diseases caused by soilborne plant pathogens in six distinct pathosystems. Disease severity frequently exhibits a U-shaped response curve, with a minimum at some intermediate biochar dose. Alteration of plant disease intensity by biochar added to soil may result from its varied influences on the soil–rhizosphere–pathogen–plant system. These influences may involve myriad biochar properties such as nutrient content, water holding capacity, redox activity, adsorption ability, pH and content of toxic or hormone-like compounds. The direct and indirect impacts of biochar on the soil environment, host plant, pathogen and the rhizosphere microbiome can have domino effects on both plant development and disease progress
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Biochar has the potential to make a major contribution to the mitigation of climate change, and enhancement of plant production. However, in order for biochar to fulfill this promise, the industry and regulating bodies must take steps to manage potential environmental threats and address negative perceptions. The potential threats to the sustainability of biochar systems, at each stage of the biochar life cycle, were reviewed. We propose that a sustainability framework for biochar could be adapted from existing frameworks developed for bioenergy. Sustainable land use policies, combined with effective regulation of biochar production facilities and incentives for efficient utilization of energy, and improved knowledge of biochar impacts on ecosystem health and productivity could provide a strong framework for the development of a robust sustainable biochar industry. Sustainability certification could be introduced to provide confidence to consumers that sustainable practices have been employed along the production chain, particularly where biochar is traded internationally.
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Purpose Rarely considered in environmental assessment methods, potential land use impacts on a series of ecosystem services must be accounted for in widely used decision-making tools such as life cycle assessment (LCA). The main goal of this study is to provide an operational life cycle impact assessment characterization method that addresses land use impacts at a global scale by developing spatially differentiated characterization factors (CFs) and assessing the extent of their spatial variability using different regionalization levels. Methods The proposed method follows the recommendations of previous work and falls within the framework and principles for land use impact assessment established by the United Nations Environment Programme/Society of Environmental Toxicology and Chemistry Life Cycle Initiative. Based on the spatial approach suggested by Saad et al. (Int J Life Cycle Assess 16: 198–211, 2011), the intended impact pathways that are modeled pertain to impacts on ecosystem services damage potential and focus on three major ecosystem services: (1) erosion regulation potential, (2) freshwater regulation potential, and (3) water purification potential. Spatially-differentiated CFs were calculated for each biogeographic region of all three regionalization scale (Holdridge life regions, Holdridge life zones, and terrestrial biomes) along with a nonspatial world average level. In addition, seven land use types were assessed considering both land occupation and land transformation interventions. Results and discussion A comprehensive analysis of the results indicates that, when compared to all resolution schemes, the world generic averaged CF can deviate for various ecosystem types. In the case of groundwater recharge potential impacts, this range varied up to factors of 7, 4.7, and 3 when using the Holdridge life zones, the Holdridge regions, and the terrestrial biomes regionalization levels, respectively. This validates the importance of introducing a regionalized assessment and highlights how a finer scale increases the level of detail and consequently the discriminating power across several biogeographic regions, which could not have been captured using a coarser scale. In practice, the implementation of such regionalized CFs suggests that an LCA practitioner must identify the ecosystem in which land occupation or transformation activities occur in addition to the traditional inventory data required—namely, the land use activity and the inventory flow. Conclusions The variability of CFs across all three regionalization levels provides an indication of the uncertainty linked to nonspatial CFs. Among other assumptions and value choices made throughout the study, the use of ecological borders over political boundaries was deemed more relevant to the interpretation of environmental issues related to specific functional ecosystem behaviors.
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Purpose Land use is a main driver of global biodiversity loss and its environmental relevance is widely recognized in research on life cycle assessment (LCA). The inherent spatial heterogeneity of biodiversity and its non-uniform response to land use requires a regionalized assessment, whereas many LCA applications with globally distributed value chains require a global scale. This paper presents a first approach to quantify land use impacts on biodiversity across different world regions and highlights uncertainties and research needs. Methods The study is based on the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) land use assessment framework and focuses on occupation impacts, quantified as a biodiversity damage potential (BDP). Species richness of different land use types was compared to a (semi-)natural regional reference situation to calculate relative changes in species richness. Data on multiple species groups were derived from a global quantitative literature review and national biodiversity monitoring data from Switzerland. Differences across land use types, biogeographic regions (i.e., biomes), species groups and data source were statistically analyzed. For a data subset from the biome (sub-)tropical moist broadleaf forest, different species-based biodiversity indicators were calculated and the results compared. Results and discussion An overall negative land use impact was found for all analyzed land use types, but results varied considerably. Different land use impacts across biogeographic regions and taxonomic groups explained some of the variability. The choice of indicator also strongly influenced the results. Relative species richness was less sensitive to land use than indicators that considered similarity of species of the reference and the land use situation. Possible sources of uncertainty, such as choice of indicators and taxonomic groups, land use classification and regionalization are critically discussed and further improvements are suggested. Data on land use impacts were very unevenly distributed across the globe and considerable knowledge gaps on cause–effect chains remain. Conclusions The presented approach allows for a first rough quantification of land use impact on biodiversity in LCA on a global scale. As biodiversity is inherently heterogeneous and data availability is limited, uncertainty of the results is considerable. The presented characterization factors for BDP can approximate land use impacts on biodiversity in LCA studies that are not intended to directly support decision-making on land management practices. For such studies, more detailed and site-dependent assessments are required. To assess overall land use impacts, transformation impacts should additionally be quantified. Therefore, more accurate and regionalized data on regeneration times of ecosystems are needed.
Purpose The inclusion of land-use activities in life cycle assessment (LCA) has been subject to much debate in the LCA community. Despite the recent methodological developments in this area, the impacts of land occupation and transformation on its long-term ability to produce biomass (referred to here as biotic production potential [BPP]) — an important endpoint for the Area of Protection (AoP) Natural Resources — have been largely excluded from LCAs partly due to the lack of life cycle impact assessment methods. Materials and methods Several possible methods/indicators for BPP associated with biomass, carbon balance, soil erosion, salinisation, energy, soil biota and soil organic matter (SOM) were evaluated. The latter indicator was considered the most appropriate for LCA, and characterisation factors for eight land use types at the climate region level were developed. Results and discussion Most of the indicators assessed address land-use impacts satisfactorily for land uses that include biotic production of some kind (agriculture or silviculture). However, some fail to address potentially important land use impacts from other life cycle stages, such as those arising from transport. It is shown that the change in soil organic carbon (SOC) can be used as an indicator for impacts on BPP, because SOC relates to a range of soil properties responsible for soil resilience and fertility. Conclusions The characterisation factors developed suggest that the proposed approach to characterize land use impacts on BBP, despite its limitations, is both possible and robust. The availability of land-use-specific and biogeographically differentiated data on SOC makes BPP impact assessments operational. The characterisation factors provided allow for the assessment of land-use impacts on BPP, regardless of where they occur thus enabling more complete LCAs of products and services. Existing databases on every country’s terrestrial carbon stocks and land use enable the operability of this method. Furthermore, BPP impacts will be better assessed by this approach as increasingly spatially specific data are available for all geographical regions of the world at a large scale. The characterisation factors developed are applied to the case studies (Part D of this special issue), which show the practical issues related to their implementation.