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1
WORKING PAPER
Forest Mitigation: A Permanent
Contribution to the Paris Agreement?
Sandro Federici, Donna Lee, Martin Herold
October 2017
This report has been funded primarily by the Norwegian International Climate and Forest Initiative, with
support from the Climate and Land Use Alliance. The authors are solely responsible for its content.
2
Executive Summary
The Paris Agreement set forth new global goals on mitigation. Recent studies
1
, as well as the
Intergovernmental Panel on Climate Change (IPCC), in its most recent Assessment Report
2
, suggest that
such goals cannot be met without a significant contribution from forests. Halting conversion of forest into
other land uses, ending forest degradation, and restoring peatlands would avoid accumulation in the
atmosphere of around 30% of global anthropogenic CO2 emissions
3
. Additionally, expanding forests is
critical to reaching carbon balance and providing the negative emissions needed to reach the 1.5°C global
set out by the Paris Agreement.
However, forest contributions have sometimes been ‘discounted’ by policy makers, climate negotiators,
and groups that claim forest mitigation is not permanent and therefore should not be considered on par
with emission reductions in, for example, the energy sector. This report suggests otherwise, for the
following reasons:
1. Forests have been sequestering carbon for thousands of millennia and have been a permanent
feature of the terrestrial biosphere. Currently, forests sequester around 30% of human-caused
emissions
4
and represent the only carbon capture and storage approach that has proven to work at
scale and at reasonable cost
5
. There is 40% more carbon stored in forests than in fossil fuel deposits
6
.
2. Because human activities impact C stocks on land, and because mitigation actions may incentivize the
substitution of fossil fuels and other energy-intensive material with wood, the inclusion of forests in
accounting frameworks is a precondition to ensure that accounted results in the energy sector
correspond to what is actually “seen” by the atmosphere.
3. To the atmosphere, avoiding emissions from deforestation and forest degradation is no different than
avoiding emissions from fossil fuels—the atmosphere sees the same thing.
4. Furthermore, the land sector is unique in that it is 'self-correcting'; emissions caused by natural
disturbances normally result, over time, in the recovery of carbon stocks, returning lost carbon back
to the land (e.g. through forest regrowth). This is not true for any other sector.
5. While natural ecosystems experience inter-annual variability, they have an average long-term C stock
(with exception of peatlands), and only changes to this long-term average permanently impact
atmospheric CO2 concentrations.
1
Rockström, J. et al (2017). A roadmap for rapid decarbonization. Science 355 (6331); Roe, S. et al (2017). How Improved Land Use Can
Contribute to the 1.5°C Goal of the Paris Agreement (Working Paper).
2
IPCC AR5 – Mitigation of climate change (http://www.ipcc.ch/report/ar5/wg3/).
3
This figure has been calculated by summing up CO2 emissions from gross deforestation, i.e. 2.8 Gt C yr-1, estimated by Goodman R.C. and Herold
M. (2014) Why Maintaining Tropical Forests Is Essential and Urgent for a Stable Climate - CGD Climate and Forest Paper Series #11 (figure 6.b
https://www.cgdev.org/sites/default/files/CGD-Climate-Forest-Paper-Series-11-Goodman-Herold-Maintaining-Tropical-Forests.pdf), from forest
degradation, i.e. 0.5 Gt C yr-1, estimated from FAO FRA 2015 data (Federici, in elaboration), from peatland drainage, i.e. 0.5 Gt C yr-1, estimated by
Wetlands International (2009) in The Global Peatland CO2 Picture (https://www.wetlands.org/publications/the-global-peatland-co2-picture/);
from all other sectors as estimated by Le Quéré, C. et al (2016), Global Carbon Budget, (Earth Systems Science Data 8, 605-649,
http://www.globalcarbonproject.org/).
4
Le Quéré, C. et al (2016). Global Carbon Budget. Earth Systems Science Data 8, 605-649 - http://www.globalcarbonproject.org/
5
Wolosin, M. (2017). Large-scale Forestation for Climate Mitigation: Lessons from South Korea, China and India.
6
Scharlemann, J. et al (2014). Global soil carbon: understanding and managing the largest terrestrial carbon pool, Carbon Management, 5:1, 81-
91, DOI: 10.4155/cmt.13.77 --- McGlade, C. and Ekins, P. (2015). The geographical distribution of fossil fuels unused when limiting global warming
to 2 °C. Nature, 517 (7533) pp. 187-190.
3
6. Primary forests have the highest long-term average carbon stocks—and therefore their protection
must be a priority.
7. To the extent there are risks of 'reversals' of a particular mitigation action, these risks exist in the
energy (and other) sectors as well as for land use and forests. All sectors have drivers of emissions
that can be reversed. Therefore, it is critical that all mitigation actions are 'transformational'
7
.
8. In the land use sector, transformational actions that reduce emissions also tend to increase removals.
And, in addition, the protected sink may persist for decades, contributing to long-term increases in C
stocks. There is also a gain in delaying land use conversion—which is not true of fossil fuels—since
forests, while they are kept standing, will remove carbon
8
.
9. The Paris Agreement and recent COP decisions that require all countries to submit national GHG
inventories (NGHGIs) and be accountable for significant categories of CO2 fluxes within their NDCs
(and continue to be accountable for them, once a source, sink, or activity is counted) is critical for the
issue of permanence. Reversals at the national level are now ‘covered’ through the long-term
responsibility of signatories to the Paris Agreement.
10. Accounting frameworks that operate on a shorter-term basis (e.g. crediting or trading mechanisms)
have developed tools to manage risks of reversals from credited removals or emission reductions.
Examples include insurance mechanisms (pooled buffer or reserve accounts), monitoring obligations
beyond the accounting period, program design requirements (to ensure long term storage of carbon
stocks), and liability provisions. Furthermore, permanence of accounted results may be ensured if
liability is transferred, after the project ends, to national reporting and accounting of a nationally
determined contribution (NDC), since the latter is a long-term commitment under Paris Agreement.
Currently, a majority of countries have made commitments to reduce emissions (or increase removals) in
the land use and forest sector through submitted NDCs under the Paris Agreement. Several donor
governments have pledged to support developing countries, in particular, with such efforts. In addition,
many large multi-national companies have pledged to take deforestation out of their supply chains. While
such transformation change is difficult to achieve, once it is in place, it can also be difficult to reverse. In
Europe
9
, there are 30% more forests since 1900 despite a significant increase in agriculture production.
Reversing forest loss conserves biodiversity, protects watersheds and ecosystem services, regulates local
climate critical for sustained rural development, and provides livelihoods for forest-dependent
communities. Science tells us that we cannot delay action if we are to avoid dangerous climate change—
and forests can contribute, in permanent ways, to meeting such a goal.
7
Transformational changes remove the driver(s) of emissions such that emissions would not occur after the end of the period of activity (further
discussed in Section 4).
8
According to Le Quéré, C. et al (2016) - Global Carbon Budget. Earth Systems Science Data 8, 605-649 – there is a large residual sink on land that
offset almost one third of anthropogenic emissions. This sink is mainly located in forest land (Schimel D. et al (2014) Effect of increasing CO2 on
the terrestrial carbon cycle, http://www.pnas.org/content/112/2/436.full, Keenan T.F. et al (2016) Recent pause in the growth rate of
atmospheric CO2 due to enhanced terrestrial carbon uptake, https://www.nature.com/articles/ncomms13428).
9
Fuchs, R. (2015). Gross changes in reconstructions of historic land cover/use for Europe between 1900 and 2010. Global Change Biology 21 (1)
4
Contents
1. Preface .............................................................................................................................................. 5
2. The role of terrestrial C pools for mitigation of climate change ........................................................ 9
3. The nature of CO2 emissions and removals from the land use sector ............................................. 11
4. Drivers of CO2 emissions and removals in the land use sector ........................................................ 14
5. Nature of results accounted for by mitigation actions in the land use sector ................................. 16
6. Permanence of accounted quantities ............................................................................................. 19
7. Addressing the risk of non-permanence under the UNFCCC .......................................................... 21
8. Addressing the risk of non-permanence under other accounting frameworks ............................... 23
5
1. Preface
The term “non-permanence” is generally used to indicate the reversal of an achieved result, while its
opposite, “permanence,” indicates the quality of a result lasting through time. While the UNFCCC does
not have an official definition of permanence in its reporting and accounting framework, references to
the term have implicitly suggested two aspects related to the results of mitigation actions:
Permanence of an emission or removal, i.e. its resident time into the atmosphere;
Permanence of the driver causing the emission and/or removal, i.e. the likelihood that after
mitigation results have been accounted, the driver(s) counteracted by the mitigation action will be
active again, reverting avoided CO2 emissions or stored CO2 removals to the atmosphere.
Non-permanence affects the integrity of any accounting mechanism for mitigation. This occurs when an
accounted unit—i.e. one that does not actually correspond to either an avoided emission or an enhanced
removal because of a reversal—has not been cancelled or offset/replaced by another accounting unit.
This report focuses on CO2 fluxes caused by human activities and on their deviation from business-as-
usual levels and trends, where such deviations are accounted as results from the implementation of
mitigation actions. When accounting for results and assessing their permanence, CO2 fluxes associated
with natural disturbances (see Box 1, page 7), as well as those associated with activities and disturbances
that occurred before the onset of the mitigation actions (i.e. the legacy effect, see Box 2, page 7), must be
zeroed, since both are not directly associated with the mitigation actions.
The Paris Agreement has established a universal obligation to regularly publish a national greenhouse gas
inventory report (NGHGI), following IPCC guidance. All countries are expected to report time series of
estimates of anthropogenic greenhouse gas (GHG) emissions and removals—including in the land sector.
Furthermore, all countries that ratify the Agreement must submit nationally determined contributions
(NDCs) that include all significant emissions and removals. These provisions should, in principle,
guarantee that any reversal is not only reported (at the time in which it occurs), but also that the country
is held liable for such reversals through accounting for its NDC.
Carbon stored in forest land represents 60% of total C stock contained in terrestrial C pools and exceeds
by 40% the total C stored in fossil deposits and by 450% the total amount of C that can be added to the
atmospheric CO2 concentration without exceeding the 2°C goal of the Paris Agreement (see Box 3, page
8). Forests currently remove almost one-third of anthropogenic CO2 emissions, and new afforestation
activities may significantly increase this mitigation effect.
However, human activities impact lands by using them for production of food and feed, biomaterials,
10
and biofuels at large scales,
11
resulting in deep alteration of resident C stocks
12
and their dynamics. An
accurate estimate of anthropogenic CO2 fluxes cannot overlook such changes. Current modeling suggests
that pathways to limit temperature increases to 2°C likely require increasing use of biomaterials and
10
According with data reported in FAOSTAT database (http://www.fao.org/faostat/en/#data/FO), around 1 Pg C yr-1 of wood has been harvested
in 2016, that where not serving from a sustainable management of forest may determine a net decrease in the long-term C stocks of forest land
and consequently a net accumulation of carbon into the atmosphere.
11
Currently, human activities are consuming around 40% of the global net primary production
(www.nature.com/nature/journal/v429/n6994/pdf/nature02619.pdf); the forecasted increase of human population and of its consumption of
biomaterials, including biofuels, and the contemporary decrease in primary production due to deforestation and land degradation, including
forest degradation, and negative impacts of climate change may likely increase such quota over 50% by 2030.
12
Deforestation only has been estimated to have transferred around 150 Pg C (1870-2016) just in the period 1870-2016.
6
bioenergy. However, if these are not sustainably produced, it would result in a significant displacement of
emissions
13
from energy-related sources to lands, especially to forest land. For these reasons, it is critical
to include forests in any accounting framework.
The Paris Agreement invites Parties to take action to conserve and enhance terrestrial sinks and
reservoirs of GHG. Nevertheless, since the advent of the Kyoto Protocol, the liability of countries and local
actors for emissions and removals from terrestrial C pools and their inclusion within market mechanisms
have been contentious within UNFCCC negotiations. Critiques have pointed to
I. the concurrence of natural factors in determining emissions and removals from the terrestrial C
pools;
II. the temporary nature of mitigation actions and consequently of their achieved results.
This report provides an analysis of the nature of CO2 emissions and removals from managed terrestrial C
pools, hereafter also referred as the land use sector
14
, and of the nature of results achieved by mitigation
actions in the land use sector. Although the analysis focuses its discussion on the permanence of climate
results achieved through mitigation activities that affect forest land, i.e. activities for reducing C stock
losses and enhancing C stocks of forests, the content of this report may be applied to all other terrestrial
ecosystems (although for peatlands, see Box 4 on page 8, such general considerations may not apply).
13
Where CO2 emissions from bioenergy are not accounted for in the land sector, bioenergy cannot be assumed to be carbon neutral since the
production and use of biofuels may determine a decrease in the long-term average C stocks of land (see figure in section 3). For instance,
according to global data on fuelwood production (http://www.fao.org/faostat/en/#data/FO), almost 2 Gt CO2 yr-1 are currently emitted by its use
although not accounted for since deemed to be at equilibrium with atmospheric CO2 concentration (i.e. the CO2 emissions will be taken back by
the subsequent regrowth of forest)
14
Sector of a NGHGI
7
Box 1. Natural Disturbances
The annual GHG net flux15 of a managed land is the result of multiple causes/drivers that can be aggregated
within three groups: (a) those directly attributed to human activities (e.g. harvesting, planting); (b) those
indirectly attributed to human activities (mainly N and CO2 fertilization, climate change); and (c) natural
disturbances (mainly fires, drought, pests).
Although it is possible to list these causes/drivers of emissions and removals, it is not possible to separate their
contribution to the total GHG net flux by cause, occurrence, or specific land area. For example, it is difficult, if not
impossible, to separate out the causes of GHG emissions and subsequent removals from forest fires. Fires have
affected forest ecosystems since before the appearance of human beings. They may be the intentional or
unintentional consequence of human activities, and their frequency and intensity is directly impacted by climate
change (and the indirect consequence of human activities). Consequently, the total emissions and removals
associated with forest fires is the result of a range of causes—anthropogenic, direct and indirect, and natural—
that influence each other and cannot be separated. Consider, for instance, a country in which all forest fires are
anthropogenic and the number of fires is the same in three consecutive years, but where summer weather
conditions vary, so the first year is wet and mild, the second dry and warm, and the third dry, hot, and windy. This
variability in weather condition is natural but also, because of climate change, indirectly-human induced. In terms
of the impacts of the forest fires, GHG fluxes associated with fires occurring in the first year will be an order of
magnitude smaller than those associated with fires occurring in the second year and much smaller than those in
the third year. So, although all fires are anthropogenic, and the frequency of occurrence is the same, the results
are different because the impact of natural variability and because of human-induced climate change. But it is
possible to statistically identify when natural causes are predominant over human causes in impacting annual net
GHG fluxes since, in such cases, the net GHG flux would exceed (i.e. be statistical outliers) the typical range of
observed variability of natural disturbances over a period of years.
Box 2. Legacy of C pool disturbances
C stocks in C pools tend naturally towards an equilibrium where C stock gains are equivalent to C stock losses.
This means that, when in one year a disturbance (natural or human-induced) alters one of the two terms of the
equilibrium, the C pool reacts in subsequent years. This can either (a) determine a net C accumulation, i.e.
annual C gains larger than annual C losses when the disturbance initially caused annual losses larger than annual
gains (e.g. harvesting/fires impacts on biomass pool), or (b) determine a net C decay, i.e. the case when the
disturbance initially caused annual gains larger than annual losses (e.g. harvesting or fire impacts on dead organic
matter pool). Consequently:
- A CO2 emission associated with a C stock loss can revert from the atmosphere because of the
subsequent vegetation regrowth;
- A CO2 removal associated with a C stock gain may revert to the atmosphere because of a subsequent
disturbance (human or natural).
Consequently, “net emission reductions” as well as “net removal enhancements” may over-account what is
actually seen by the atmosphere across a time period longer than the time period of accounting for mitigation
results. Similarly, “net emission increases” as well as “net removal decreases” may be over-accounted if the
legacy effect is not zeroed.
15
and the associated long-term average C stock
8
Box 3. Representative Concentration Pathways
Representative Concentration Pathways (RCPs) are GHG concentration (not emissions) trajectories adopted by
the IPCC for its AR5. They describe four climate futures, all of which are considered possible depending on GHG
emissions in the years to come. The RCPs (RCP2.6, RCP4.5, RCP6.0, and RCP8.5) are named after a possible range
of radiative forcing values in the year 2100 relative to pre-industrial values (+2.6, +4.5, +6.0, and +8.5 W/m2,
respectively).
AR5 global warming increase (°C) projections
time period
2046-2065
2081-2011
Scenario
Mean and likely range
RCP2.6
1.0 (0.4 to 1.6)
1.0 (0.3 to 1.7)
RCP4.5
1.4 (0.9 to 2.0)
1.8 (1.1 to 2.6)
RCP6.0
1.3 (0.8 to 1.8)
2.2 (1.4 to 3.1)
RCP8.5
2.0 (1.4 to 2.6)
3.7 (2.6 to 4.8)
Box 4. Peatlands
Peatlands are a part of the terrestrial carbon pool. However, unlike forests that (if left undisturbed) have a long-
term average C stock, the C stored in peatlands does not tend toward an equilibrium. Peat can sequester an
unlimited amount of C if pedoclimatic conditions (i.e. soil temperature, water, aeration) allow.
Without human intervention, most of the C stored in peatlands would not react with the atmosphere.
Consequently, peat may be considered a fossil C stock that would not be emitted to the atmosphere without
human action and, accordingly, any avoided emission is a permanent reduction of emissions.
However, if drivers of peat degradation have not been permanently removed—which means that peat may be
disturbed in the future—the original action to avoid peat emissions is no different, and no less permanent, than
an avoided fossil fuel emission.
9
2. The role of terrestrial C pools for mitigation of climate change
Terrestrial C pools contain the stocks of living organic matter (biomass) and dead organic matter (dead
wood, litter, soil organic C, and harvested wood products) associated with vegetation. Such biomass pools
remove CO2 from the atmosphere (i.e. they are a carbon sink) because of net photosynthesis, and emit
CO2, CH4 and N2O from redox
16
of organic matter associated with continuous processes such as decay
17
or
sudden events such as wildfires.
Terrestrial C pools store around 1.9 Eg
18
of C (~1.4 in soils and ~0.5 in phytomass)
19
, mainly in forests
20
(1.1 Eg C), and peatlands
21
(0.6 Eg C). The total is a quantity larger than the C stored in fossil fuels
reserves (~0.8 Eg C)
22
, and more than the carbon already added to the atmosphere as a consequence of
human activities since 1870 (~0.6 Eg C)
23
. This stored quantity also exceeds the quota of emissions that
can be added to the atmosphere in order to keep the increase in average global temperature below 2 °C
(0.2 Eg C)23.
Until 1950, CO2 emissions from terrestrial C pools were the main flux of CO2 emissions caused by human
activities. Around one-quarter of total anthropogenic CO2 emissions since 1870 have been sourced from
terrestrial C pools23. In recent years, largely due to the growth of fossil fuel emissions, net land use
change (largely deforestation) has declined to around 10%
24
of total global anthropogenic CO2
emissions—but more importantly, the land sector (largely forests) remove from the atmosphere 30% of
total anthropogenic CO2 emissions23. If only anthropogenic emissions (and not removals) are considered,
gross deforestation, forest degradation, and peatlands drainage would together comprise around 30% of
global total CO2 emissions3.
Due to their dual role as both a source and sink in the global C budget, terrestrial C pools have been
recognized as key actors to achieve stabilization of atmospheric concentration of GHG at a level that does
not seriously harm human, socio-economic, and natural systems. Indeed, halting the conversion of forest
land and peatlands into agricultural or other lands and preserving the current land sink
25
would avoid
accumulation in the atmosphere of more than one-third of global anthropogenic emissions
26
. In other
words, failing to protect and sustainably manage forests and peatlands will accelerate by almost one-third
the current pace of C accumulation into the atmosphere.
On the other hand, enhancing the current sink, especially through afforestation and rewetting of drained
peatlands, would further increase the mitigation potential of terrestrial C pools. The IPCC, in its latest
16
Redox reactions include all chemical reactions that involve the transfer of electrons between chemical species. The chemical species from
which the electron is lost is said to have been oxidized (gain of oxygen), while the chemical species to which the electron is added is said to have
been reduced (loss of oxygen). Oxidation is generally associated with oxygen availability (oxic conditions) while reduction with anoxic conditions.
17
Decay processes determine a chain of organic compounds with a continuous loss of weight, also caused by CO2 emissions, from biomass to
dead wood and litter to soil organic matter and its subsequent respiration to CO2 emissions.
18
An Exagram corresponds to 1018 grams or a thousand Gt, e.g. 1.9 Eg C corresponds to 1,900 GtC.
19
Scharlemann, J. et al (2014). Global soil carbon: understanding and managing the largest terrestrial carbon pool, Carbon Management, 5:1, 81-
91, DOI: 10.4155/cmt.13.77
20
2000 IPCC special report on Land Use, Land-Use Change and Forestry
21
Note that some forests occur on peatlands
22
McGlade, C. and Ekins, P. (2015). The geographical distribution of fossil fuels unused when limiting global warming to 2 °C. Nature, 517 (7533)
pp. 187-190.
23
Le Quéré, C. et al (2016). Global Carbon Budget. Earth Systems Science Data 8, 605-649 - http://www.globalcarbonproject.org/
24
Net deforestation from Le Quéré, C. et al (2016). Global Carbon Budget. Earth Systems Science Data 8, 605-649 -
http://www.globalcarbonproject.org//
25
Including by avoiding forest degradation
26
Around 11.6 Gt CO2 yr-1
10
assessment report
27
, considers the role of terrestrial C pools, particularly large-scale afforestation, critical
to avoiding global warming above 2 °C
28
. Such mitigation potential is reflected in NDCs under the Paris
Agreement, where the management of terrestrial C pools, especially forests, constitutes one-quarter of
the collective commitment
29
. A failure to achieve this mitigation would double the gap
30
between current
NDCs and a global net emission benchmark consistent with a pathway
31
to keep global warming below
2°C.
Further, forests are the habitat of around 80% of terrestrial biodiversity and provide indispensable and
irreplaceable services beyond C sequestration and storage. Forests regulate local climate, enhance air
quality, prevent soil erosion, improve soil fertility, and increase water availability and quality—leading to
more reliable food production and advancing other societal goals.
Summary: The role of terrestrial C pools for mitigation of climate change
Forest land stores 60% of the total C stock contained in terrestrial C pools.
Forest land contains 40% more C than that contained in fossil fuels deposits.
Forest land contains almost five times more C than can be added to the atmosphere without
exceeding the 2 °C goal.
The net CO2 balance of land use change (largely deforestation) is currently responsible for
around 10% of global anthropogenic CO2 emissions; while gross deforestation, forest
degradation and peatlands drainage are collectively responsible for around 30% of the global
total. But forests also remove almost one-third of total emissions due to forest management,
including natural forest expansion, and the indirect effects of human activities. New
afforestation activities may significantly increase this mitigation effect.
Failing to protect and expand the carbon stored in forests will make it impossible to achieve
Paris Agreement goals.
27
https://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_summary-for-policymakers.pdf
28
According to the mitigation scenarios and associated RCP2.6, failure in achieving net emissions at scale by 2050 will lock societies in a high
temperature future.
29
Grassi G. et al (2017). The key role of forests in meeting climate targets requires science for credible mitigation. Nature Climate Change,
doi:10.1038/nclimate3227
30
http://climateactiontracker.org/global/173/CAT-Emissions-Gaps.html (~14.5 Gt CO2eq yr-1)
31
RCP2.6
11
3. The nature of CO2 emissions and removals from the land use sector
Before discussing the nature of CO2 fluxes from land, it is worth briefly discussing the nature of CO2
emissions generated by the use of fossil fuels, since they are the largest share
32
of anthropogenic CO2
emissions and the core of any accounting framework for mitigation. Carbon contained in fossil fuels is
stored in geological deposits confined from the atmosphere. Because of human activities that extract and
oxidize it, fossil C is added to the atmosphere, or more precisely to the atmosphere-land-ocean system
33
.
These emissions are permanent, because the carbon does not revert to the geological deposits
34
.
The organic carbon contained in terrestrial C pools is in dynamic equilibrium with the atmosphere,
subject to natural and human-induced processes of accumulation from the atmosphere into the C pools
and of subsequent decay to the atmosphere
35
. This equilibrium can be quantified as a long-term average
C stock stored in each terrestrial C pool
36
. The long-term average C stock takes into consideration the
resident time of C within the C pools (see Box 5 below) and is determined by the ecological conditions,
the system of management practices (i.e. land use) and the associated regime of natural and
anthropogenic disturbances. A change in any of these factors can result in a change in the long-term
average C stock.
Box 5. Long-term average C stock of various forest types
In the three graphs, the blue lines represent the C stock level across time, with C stock losses followed by
equivalent C stock gains. Although in all three forests types there are CO2 emissions and removals across time, it
is possible to calculate a long-term net impact on the atmospheric CO2 concentration for each of them i.e. their
long-term average C stock (the dotted lines). Although the three forest types have almost equivalent peaks of C
stock, the different resident time of carbon in C pools makes each forest’s contribution to the atmospheric CO2
concentration significantly different. As illustrated in the graphs, compared to primary forests, the long-term
average C stock of secondary forests is 25% lower and forest plantations is 50% lower.
Consequently, the conversion of a primary forest to a secondary forest or to a forest plantation results in a
permanent loss of C stock and therefore a permanent increase in the atmospheric CO2 concentration.
Alternately, the conversion of a forest plantation to a secondary forest or of a non-forest land to a forest land is a
permanent C stock gain and therefore a permanent decrease in the atmospheric CO2 concentration.
32
72% of total CO2 emissions since 1870 have originated from fossil fuels.
33
According to the globacarbonproject.org, 26% of CO2 emitted to the atmosphere since 1870 has been absorbed by oceans, 31% has been
absorbed by land, and the remaining 44% has accumulated in the atmosphere.
34
Ignoring extremely long-term geological processes.
35
Peatlands are an exception, since they act as an almost unlimited C sink (Box 4).
36
The long-term average C stock at equilibrium in a land use and management system of practices is the average C stock stored in the land across
one or several cultural cycles—allowing C pools to achieve their equilibrium status.
12
The long-term average C stock of a land represents what the atmosphere sees as the land’s overall
contribution to the atmospheric CO2 concentration, although annually CO2 emissions may not be
equivalent to CO2 removals. Consequently, any net change in the long-term average C stocks caused by a
change in activities (e.g. a change in land use or management) results in a total permanent net impact
37
on the atmosphere.
The reporting instrument under the Paris Agreement, the NGHGI, is a permanent obligation that requires
all countries to submit regular (at least every two years) time series of estimates of annual anthropogenic
CO2 emissions and removals. All annual CO2 emissions and removals are reported within NGHGIs, and
their net impact on the atmosphere should be estimated. Within the cultural cycle (e.g. harvest and
regrowth), CO2 emissions in one year may be offset by CO2 removals in subsequent years, and vice versa.
Consequently, over time, NGHGIs should capture any changes in long-term average C stocks as the net
permanent effect of time series of annual emissions and removals. In other words, the sum of annual CO2
fluxes across the conversion period
38
should reflect the total net change in the long-term average C
stock
39
and therefore the net impact on atmospheric CO2 concentration (see Box 6 on next page).
As noted in Box 4 (page 8), peatlands do not have a long-term average C stock level, since they tend to
accumulate carbon indefinitely if the pedoclimatic conditions allow. Human activities, however, may turn
the indefinite CO2 sink into a CO2 source. These fluxes are permanent, since stored CO2 is not emitted in
absence of a human intervention and no CO2 is sequestered back into the land unless an additional and
opposite human intervention occurs.
Summary: Nature of CO2 emissions and removals from the land use sector
CO2 emissions from fossil fuels are a permanent addition to the atmosphere, although a portion
of these emissions is annually removed by the land and ocean.
CO2 emissions from land may have a limited resident time in the atmosphere; the long-term
average C stock of the land represents the permanent impact of land on atmospheric CO2
concentration.
Changes in the long-term average C stock from land use are long-term permanent CO2 addition
to, or subtraction from, the atmosphere and therefore comparable with net changes in CO2
emissions from fossil fuels.
Changes in the long-term average C stocks of a land are reported, when they occur, within a
NGHGI as annual CO2 emissions and removals, whose sum across a time series (covering the full
conversion period) quantifies the permanent net flux.
37
The IPCC’s basic assumption is that the impact of changes in human activities stands for 20 years (i.e. transition period); after such period a
new equilibrium is achieved and the impact of the change may be assumed completely counted.
38
i.e. the time need to C stocks to move from the long-term equilibrium of the previous use and/or management system to the new one.
39
Indeed, counting the annual losses and gains of C in a conversion from e.g. a primary forest to a secondary forest would ultimately count for the
net difference between the two long-term average C stocks (see Box 5).
13
Box 6. Impact on atmospheric CO2 of a forest management change, from clearcut to selective logging
For any year of a time series, the sum of CO2 emissions and removals may be calculated to reflect the impact on
atmosphereic CO2 concentration in that year from a management change. The total net impact of the
management change, however, would be the change in the sum of annual fluxes across complete management
cycles. In the figure below, for example, it would mean comparing the time series of annual CO2 emissions and
removals during the management cycles of clear-cut harvesting (e.g. time a. to time just before c.) to the annual
CO2 emissions and removals during management cycles of selective logging (from c. to the end of cycle d.). In
this case, the comparison of total net CO2 emission/removal across the management cycles gives the long-term
average C stocks increase (as demonstrated in Figure B) caused by the the conversion from clearcut to the
selective logging system.
Figure A: Annual C stock changes (CO2 emissions and removals) reported in the NGHGI
Note: Green bars are negative values representing forest growth (CO2 removals); red bars represemt forest harvesting (CO2
emissions)
Figure B: C stocks dynamic in forest land
Note: The blue lines represent C stocks and the orange lines represent long-term average C stocks
14
4. Drivers of CO2 emissions and removals in the land use sector
As noted in the Preface, under the UNFCCC reporting and accounting framework the term “permanence”
refers to two aspects of the results of mitigation actions
40
:
A. Permanence of an emission or removal, i.e. its resident time within the atmosphere;
B. Permanence of the driver causing the emission and/or removal, i.e. the likelihood that, after
mitigation results have been accounted for, the driver(s) that was counteracted by the mitigation
action will be active again, resulting in the accounted emission reduction or removal to be then
emitted.
Regarding A, the previous section of this report concluded that because both CO2 emissions and removals
from terrestrial C pools may be part of a unique activity, e.g. forest harvesting and subsequent forest
regrowth, the CO2 resident time of an emission (into the atmosphere) or a removal (into the C pools) in
the land use sector may be shorter than that of an emission from a fossil fuel. But, the long-term average
C stock that establishes full comparability among CO2 fluxes generated by the land use sector and those
from other sectors of the NGHGI.
This section focuses on the second aspect of permanence: the drivers of CO2 emissions and removals.
Drivers determine whether an achieved result, i.e. an avoided emission or enhanced removal, may be
reversed in the future. In case a mitigation action does not remove the drivers permanently, it may again
cause CO2 emissions after the action ends. For example, a hectare of forest saved this year from
conversion because of specific enforcement activities may be converted in a following year if such
enforcement is halted; similarly, an amount of fossil fuel not used in a particular year because of an
incentive related to public transport may be emitted in a following year if the incentive is not renewed.
Consequently, within a project- or program-based accounting framework, only projects or programs
41
that implement transformational changes may ensure permanence of achieved results, because they
remove the driver(s) of emissions such that emissions would not occur after the end of the period of
activity. For instance, shifting to a vegetarian diet would permanently reduce one’s carbon footprint, or
the designation of a forested national park would preserve all achieved C stock gains and would avoid
further C stock loss. Similarly, phasing out internal combustion engines and replacing them with electric
engines coupled with the use of renewable energy can permanently reduce the carbon footprint of the
transportation sector.
On the other hand, within a NGHGI-based accounting framework as the Paris Agreement, no emissions
will be unaccounted after the end of the mitigation actions since NDCs and the underlying NGHGI are a
permanent obligation of each country. Consequently, the permanence (or non-permanence) of drivers
should not impact the accounted quantities over time, since any emission that occurs after the end of the
mitigation action should be reported and accounted.
Considering first fossil fuels emissions, the only driver is human activity. Human activities cause fossil fuel
redox and associated GHG emissions, such that an increase
42
in activities drive a rise of GHG emissions
(although additional emissions may be avoided through energy efficiency and renewable energy).
Consequently, any variation in the amount and trend of GHG emissions from fossil fuels occurring in any
year across a time series is an indicator of a change, occurring in that year, of the unique driver. While
40
i.e. reduced emission or enhanced removal
41
Without distinction among sectors of the NGHGI targeted by the project
42
Associated with human population growth and with intensification of activities
15
replacing fossil fuels with renewable power may be considered as transformational change, other
instruments used as incentives to reducing using fossil fuels, or fiscal measures to make their use more
onerous, may exhaust their impact once they are halted or they may be neutralized by the market, with a
consequent reversion to fossil fuel use and associated GHG emissions.
In the land use sector, the annual C stock balance of a managed land is determined by the concurrent
impacts of human activities and natural variables
43
. The impact of natural variables may materialize as
disturbances
44
that, in extraordinary cases, may be predominant over human activities in determining CO2
emissions and removals from land. However, while human activities result in a permanent net change in
the long-term average C stock of a land, a natural disturbance only causes temporary C stock losses.
Indeed, after a disturbance, forest regrowth accumulates C stocks to their pre-disturbance levels (see
figure in Section 3 box) particularly in primary forests, where decreases in C stocks are exclusively caused
by natural disturbances. Therefore, although natural disturbances may impact the annual CO2 flux of an
area of land, their occurrence does not impact the long-term net flux, since associated emissions and
removals balance out across time.
Drivers of CO2 emissions and removals in the land use sector have another significant characteristic: they
impact CO2 emissions and removals in the year of occurrence but also in subsequent time periods.
Indeed, both human activities and disturbances result in processes of C accumulation—e.g. forest
regrowth after harvesting or decay— that remain active well beyond the year of occurrence. This
characteristic is generally referred to as ‘legacy effect’. This means that the positive impact of a mitigation
action usually lasts, or sometimes even increases, in years subsequent to implementation of a mitigation
action; for example, the revegetation or afforestation of degraded land may continue to accumulate
carbon for centuries after the initial establishment.
Transformational changes in the land use sector are usually associated with legislation or policies, e.g. the
designation of a national park or changes that clarify land tenure or increase land security for local
communities. Other actions may also result in permanent changes to drivers, such as the establishment
of rules and guidance for the sustainable management of degraded land.
Summary: Drivers of CO2 emissions and removals, including in the land use sector
Without distinction among sectors (applies to both fossil fuels and land use):
o human activities that drive emissions may return as soon as a mitigation action ends or loses
its effectiveness; transformational changes address drivers far beyond the end of the initial
mitigation action;
o any reversal of accounted avoided emissions/enhanced removals should be eventually
reported within repeated NGHGIs; due to their long-time horizon, NGHGIs quantify the
impact of recurrent drivers that reverse previously accounted quantities.
In the land use sector:
o addressing drivers of emissions often also results in additional CO2 removals; a failure to
recognize such CO2 removals would bias the accounted results.
43
Most relevant are the temperature and humidity regimes.
44
E.g. forest fires, which were an important ecological factor also before the appearance of the human beings (natural disturbance). Noting
however, that from the appearance of humans, forest fires are also a consequence, direct and indirect, of human activities (anthropogenic
disturbance).
16
5. Nature of results accounted for by mitigation actions in the land use sector
The goal of mitigation actions, for any sector, is to reduce atmospheric concentration of GHG or to avoid
further increases. Mitigation results (AQMR) are therefore accounted as the achieved deviation from the
GHG fluxes that would occur in absence of the action i.e. the counterfactual value
45
. Mitigation results
(AQMR) are thus accounted by subtracting expected GHG fluxes (GHGEXPECTED) from actual GHG fluxes
(GHGACTUAL): AQMR = GHGACTUAL - GHGEXPECTED.
As discussed in the previous section, when accounting for mitigation results in the land use sector, legacy
effects of activities and disturbances that occurred before the onset of the mitigation action, as well as
the impact of ongoing natural disturbances, may impact annual GHG fluxes—i.e. annual GHG fluxes may
include emissions or removals not associated with the specific mitigation actions taken within the
reporting year. Because fluxes average out across long time periods (e.g. the time needed to forest
biomass to regrow after a disturbance, or the time period for dead organic matter originating from a
disturbance to oxidize), the results accounted across a limited time period may not reflect what is actually
seen by the atmosphere as a consequence of the mitigation action. For such reason, when accounting for
results of mitigation actions in the land use sector, emissions and removals due to the legacy of previous
human activities, as well as those associated with natural disturbances, should be separated out from the
GHG balance of each land area. In practice, what is needed is to identify and measure the signal (the
mitigation results from actions taken) separate from the noise (the legacy effects and natural
disturbances).
To manage legacy effects, two conditions should be satisfied in the accounting:
A. legacy emissions/removals from activities and disturbances that occurred before the onset of the
mitigation action should be accounted as zero (while no anthropogenic flux should be excluded);
B. mitigation results are accounted across a time period equal to the period needed to exhaust the
legacy effect caused by the mitigation action.
Such conditions may be satisfied by the following two approaches that may be implemented to deal with
the legacy effect on accounting for mitigation results:
Approach I reflects what is currently done under the Kyoto Protocol accounting, where:
to comply with A: the legacy emissions and removals associated with activities and disturbances
that occurred before the onset of the mitigation action are projected, quantified, and included
within the counterfactual (baseline) value, and
to comply with B: an indefinite time series of annual GHG inventories is accounted for.
Approach II reflects what is currently implemented under REDD-plus accounting
4647
, where:
to comply with A: it is implicitly assumed that C stocks on the land are at their long-term average
C stock, and
45
This is usually referred as base year, reference level, or baseline.
46
This is the approach applied in the Method & Guidance Documentation of the Global Forest Observation Initiative (MDG-GFOI at
http://www.gfoi.org/methods-guidance/) for REDD-plus activities
47
This approach also corresponds to the IPCC default Tier 1 methodological approach to estimate net C stock changes in the soil organic matter of
mineral soils as consequence of changes in the land use and/or in the land management system of practices. This methodological approach uses
the two values of long term average SOC at equilibrium associated with use and management of the land before and after the change to estimate
the net C stock change across a transition period.
17
to comply with B: the overall impact of the mitigation action on the so-called long-term average C
stock of the land is reflected by the quantified changes during the monitoring period.
To deal with natural disturbances, the condition to be satisfied to ensure that non-anthropogenic
emissions and removals are accounted for as zero, and that no anthropogenic emissions and removals are
excluded from accounting:
the amount of CO2 emissions
48
(CO2END) and CO2 removals (CO2RND) reported as associated with
natural disturbances must average out
49
across time (CO2END = CO2RND).
Within an accounting framework like the Kyoto Protocol, such condition is satisfied through accounting as
zero the GHG emissions associated with a natural disturbance, but also counting as zero all subsequent
CO2 removals until the C stocks on the same land achieve pre-disturbance levels. Although the lag in the
residence time of C stocks has a temporary
50
impact on atmospheric CO2 concentration, the approach
excludes from accounting such temporary impact, since it is neither caused nor materially influenced
from the mitigation action to be accounted for (see also Box 1, page 7).
Summary: Nature of results accounted for by mitigation actions in the land use sector
Mitigation results (AQMR) are deviations associated with actions aimed at reducing the
atmospheric concentration of GHG or avoiding further increases. Thus, they are accounted by
subtracting the expected GHG fluxes (GHGEXPECTED), i.e. the counterfactual (baseline) value, from
actual GHG fluxes (GHGACTUAL), i.e. what the atmosphere has seen, AQMR = GHGACTUAL–GHGEXPECTED.
In the land use sector, the contribution of legacy emissions and removals, as well as emissions
and removals from natural disturbances, should be accounted as zero, since they are not
associated with the implemented mitigation actions.
To zero the contribution of legacy emissions and removals associated with activities and
disturbances that occurred before implementation of the mitigation actions and to count all
legacy effects of the implemented mitigation actions:
- either legacy emissions/removals are included in the counterfactual (baseline) value and
mitigation results are accounted through an indefinite time series of GHG inventories, or
- C stocks are assumed to be at their long-term equilibrium and the entire difference in long-
term C stocks caused by mitigation actions is accounted for.
To zero the contribution of natural disturbances, the amounts of CO2 emissions and removals
associated with natural disturbances and accounted for should balance out.
48
The other 2 GHG, CH4 and N2O, decay in the atmosphere to other compounds so that their emissions balance always to zeros across the 100-
year time frame of GWP’s.
49
This is the approach implemented in the 2013 IPCC KP Supplement (http://www.ipcc-nggip.iges.or.jp/public/kpsg/index.html)
50
This means that the C stocks of the land remain within the long-term average C stock at equilibrium.
18
Summary of Sections 1 to 5
In the previous sections, the nature of CO2 emissions and of removals, as well as the drivers of such
emissions and removals have been discussed, with the following conclusions:
Any CO2 emission from fossil fuels, including peat51, is a net addition to the atmosphere-land-
ocean (biosphere) system and results in a proportional52 increase of atmospheric CO2
concentration;
CO2 emissions from terrestrial C pools (i.e. land use sector) may be either:
o A temporary increase in atmospheric CO2 concentration if the long-term average C stock of
the land of origin does not change. This is the case if the emission is a consequence of a
natural disturbance (e.g. wildfire) or a management practices where the CO2 emitted will
be balanced out across time by subsequent CO2 removals from the land; or
o A permanent increase in the atmospheric CO2 concentration. This is the case if the emission
is consequence of a change in the land use and/or management system that determines a
decrease of the long-term average C stock, since the CO2 emitted is not expected to be
balanced out by subsequent CO2 removals from the land.
Similarly, CO2 removals from terrestrial C pools may cause either a permanent or a temporary
decrease of the atmospheric CO2 concentration, depending on whether they are associated
with an increase of the long-term average C stock or not.
Whether from fossil fuels or terrestrial C pools, any emission avoided within a time frame can
subsequently occur—resulting in a reversal—if its drivers have not been permanently
addressed.
Similarly, any CO2 removal associated with an increase of the long-term average C stock may
be subsequently reversed if the drivers that previously impeded such increase have not been
addressed permanently.
NGHGIs include a time series of all national GHG emissions and removals. They aim to include
only those caused by the national socio-economic system (i.e. anthropogenic fluxes) and
reflect the impact of such systems on the atmospheric GHG concentration. Within the time
series the temporality/permanency of GHG fluxes is properly reflected such that the sum of
the time series corresponds to the actual net impact in the atmospheric GHG concentration
caused by the country, from the first year till the last year of the time series.
Changes in the NGHGI trend provide information on achieved reduction of emissions and/or
enhancement of removals.
51
See Box 4, page 8 for details on peat as a fossil C stock
52
According to Le Quéré, C. et al (2016). Global Carbon Budget. Earth Systems Science Data 8, 605-649 - http://www.globalcarbonproject.org/,
44% of the annual CO2 emissions accumulate into the atmosphere, 31% are sequestered by terrestrial C pools (mainly forests) and 25% by
oceans.
19
6. Permanence of accounted quantities
In this section the permanence of accounted quantities is analyzed. Accounted quantities are the reduced
emissions, or the enhanced removals, achieved and measured during an accounting period against a
counterfactual
53
baseline level.
There is no official definition of permanence under the UNFCCC. However, within the UNFCCC,
permanence was first discussed within the CDM, in relation to net C stock accumulation accounted in
project activities related to afforestation and reforestation (AR-CDM). Because project activities have a
limited timeline, there is no certainty that achieved results will persist after the end of the project activity.
Such uncertainty stems from the lack of knowledge about the future use of the land, i.e. whether the
drivers (e.g. alternative use of forest land) have been addressed by the project activity temporarily or
permanently. For such reason accounted units expire at the end of the monitoring period
54
.
Subsequently, permanence was discussed again under the CDM in relation to avoided emissions from
Carbon Capture and Storage (CCS) project activities. Avoided emissions by CCS are considered to have
been permanently achieved 20 years
55
after the end of the crediting period (i.e. from 20 to 41 years after
the emissions has been avoided). This means that it is assumed, after 20 years, that the likelihood of a
reversal of results (e.g. emissions’ leakage from geological deposits) is zero—i.e. all the CO2 is assumed to
have moved from the system atmosphere-land-ocean to the geological deposit. Thus, because the CO2 is
no longer considered part of the atmosphere-land-ocean system, the accounted units do not expire and
are considered permanent.
Permanence of mitigation results is therefore an issue that stems from the limited time scale of
mitigation activities compared with the time frame of the UNFCCC’s objective to stabilize atmospheric
GHG concentration at a level that does not seriously harm human socio-economic systems as well as
natural ecosystems. It is an issue relevant for any accounting system, in particular when project or
program proponents that generate emission reductions are not liable for reversals of accounted results
that occur beyond the monitoring period. In other words, when a non-permanent unit is accounted, it
does not correspond to actual mitigation, and consequently undermines the integrity of the accounting
framework.
Thus, when discussing permanence of mitigation results, the time frame of the accounting mechanism
determines whether there is a gap in the liability for any subsequent reversal of accounted results. The
UNFCCC
56
and its associated Kyoto Protocol
57
and Paris agreement
58
all reference long-term achievement
of results. The IPCC, in its AR5
59
and in the special report on CCS
60
, uses the word “long-term”
61
to
indicate the time period needed to achieve stabilization of atmospheric CO2 concentration at a safe
level
62
, and establishes that a long-term result is one achieved up to the end of this century.
53
The GHG emissions and removals that would occur in absence of mitigation.
54
See section F. for a description of the provisions implemented under AR-CMD to address non-permanence of accounted units
55
See UNFCCC decision 10/CMP.7
56
“...modifying long term trends in anthropogenic GHG [net] emission…”
57
“...long term benefits related to mitigation…”
58
“…long term temperature goal…” and “…long term low GHG [net] emission development strategies…”
59
2013, IPCC 5th Assessment report. Working Group 1: The physical Science Basis (http://www.ipcc.ch/report/ar5/wg1/)
60
2005 IPCC Special Report on Carbon Dioxide Capture and Storage (http://www.ipcc.ch/report/srccs/)
61
The very long-term objective is to further reduce it towards pre-industrial levels.
62
This level is currently established around 450 ppm of CO2 atmospheric concentration (IPCC AR5, 2014 - https://www.ipcc.ch/pdf/assessment-
report/ar5/syr/AR5_SYR_FINAL_SPM.pdf)
20
For NGHGIs, the IPCC has implicitly established a 100-year time frame by calculating the global warming
potential (GWP) of each GHG as the average
63
warming effect caused across a century. So, consistent
with the UNFCCC’s objective, NGHGIs report levels and trends of anthropogenic GHG emissions and
removals, with the aim to assess:
the contribution of human activities to the (increasing) concentration of GHG into the
atmosphere, and
the results of implemented mitigation policies and measures.
Further, in its special report
64
on Land Use, Land-Use Change, and Forestry, the IPCC defines Permanence
as: “The longevity of a carbon pool and the stability of its stocks, given the management and disturbance
environment in which it occurs”
65
. The “long-term average C stock at equilibrium,” as defined in the
previous section of this report, fully corresponds to such description. The long-term average C stock
measures the “permanent” negative
66
(or positive) contribution of the land to the atmospheric CO2
concentration, taking into consideration the impact of the management system of practices and of the
natural disturbances regime.
Thus, consistent with the IPCC and UNFCCC reporting framework, those results that stand for a century
are permanent. This means that:
the avoidance of GHG emissions from fossil fuels, including peat, is permanent if the driver of
such emissions is permanently addressed by the project (i.e. transformational changes);
the avoidance of CO2 emissions from fossil fuel combustion through CCS is considered permanent
after 20 years have passed, i.e. the C is considered to be permanently injected in the geological
deposit;
the avoidance of CO2, and non-CO2, emissions from land is permanent so far as the long-term
average C stock of the land does not change, i.e. if the use and/or management system of
practices of the land does not change;
the sequestration of CO2 removals is permanent so far as it is associated with an increase of the
long-term average C stock; considering that per IPCC default assumption such change occurs
within a 20-year period, after a 20-year period the CO2 removals can be considered permanent.
When accounting for mitigation results, the length of the monitoring period therefore determines
whether achieved results are permanent, i.e. whether they stand for a century, or not.
Since project activities are always implemented for a shorter time period than a century, their mitigation
results may not be considered permanent, with the exception of CCS whose CO2 has been sequestered
apart from the atmosphere-land-ocean system, unless the liability for potential reversal beyond the end
of the monitoring period of the project activity is addressed.
63
GWPs are calculated in function of the GHG’s resident time in the atmosphere
64
2000 IPCC Special Report on Land Use, Land-Use Change, and Forestry (available at www.ipcc.ch/ipccreports/sres/land_use/index.php?idp=0)
65
It further discusses: “Enhancement of C stocks resulting from land use, land-use change, and forestry activities is potentially reversible through
human activities, disturbances, or environmental change, including climate change. This potential reversibility is a characteristic feature of
LULUCF activities in contrast to activities in other sectors. This potential reversibility and non-permanence of C stocks may require attention with
respect to accounting, for example, by ensuring that any credit for enhanced C stocks is balanced by accounting for any subsequent reductions in
those C stocks, regardless of the cause”
66
i.e. the amount of CO2 subtracted permanently from the atmosphere,
21
On the other hand, if project activities occur within the scope of coverage of a long-term national
commitment, e.g. as strata/subdivisions of the NGHGI’s categories, permanence may be considered
addressed—i.e. since liability would reside with the project implementers until the end of the monitoring
period, and then transfer to the country thereafter.
Summary: Permanence of accounted quantities
There is no official definition of Permanence under the UNFCCC, although it has been
discussed in relation to liability for reversal of accounted mitigation results (e.g. within the
CDM, for Afforestation/Reforestation and Carbon Capture and Storage project activities).
With the exception of net emission reductions achieved through CCS, any mitigation result
may be reverted if the drivers of emissions are not permanently addressed by the mitigation
action.
Under the UNFCCC and IPCC reporting framework the timeline for long-term (permanent)
results is the century. Accordingly:
o Project activities may not account for permanent results, unless liability of potential
reversal beyond the monitoring period is addressed (CCS is an exception);
o Results accounted through NGHGIs are always permanent, since the time frame of NGHGIs
ensures that any reversal that occurred within the century would be accounted.
If the scope of project activities falls within national accounting for an NDC (e.g. a forest carbon
project occurs on land within a country that accounts in its NDC for the same forest land),
permanence is addressed by shifting liability from the short-term project to the long-term
national commitments of the country in which the project resides.
7. Addressing the risk of non-permanence under the UNFCCC
Under the UNFCCC the risk of non-permanence of accounted results has been so far recognized for Kyoto
Protocol-LULUCF activities and for AR and CCS project activities under the CDM. For other CDM activities,
non-permanence has not been considered an issue. This is because either the project activity is assumed
to permanently addresses the drivers of emissions, e.g. when a renewable energy power plant is built, or
because it has been implicitly assumed that emissions occurring after the end of the project
implementation are not associated with the project itself, e.g. when a bioenergy power plant drives in a
region the overexploitation of biomass stocks.
UNFCCC provisions are aimed at addressing the risk of non-permanence, instead of just minimizing, its
impact on accounting. Thus, for Kyoto Protocol accounting, the risk of non-permanence has been fully
addressed by:
ensuring that once a land is accounted for it must stay within the accounting forever
67
, and
reported within the NGHGI. This means that any reversal is reported in the NGHGI and accounted
for in the year(s) in which it occurs;
67
This ensures that any reversal is timely reported and accounted for.
22
requiring countries that experience natural disturbances in a given year—and that take out of the
accounting emissions from such a disturbance event—to also take out of the accounting in
subsequent years the regrowth that occurs up to the same amount;
issuing temporary credits for AR-CDM project activities that expire at the end of the monitoring
period (although they can be renewed for subsequent crediting periods
68
). This means that any
future reversal is pre-emptively accounted for at the end of the monitoring period. It is worth
noting that: (a) such a solution likely leaves a portion of mitigation results unaccounted for, since C
stocks may need a period longer than the established monitoring period to fully account for the
increase in the long-term average C stock and (b) although based on the net increases of long-term
average C stocks, mitigation results are accounted for as temporary because of the precautionary
principle;
ensuring the monitoring of CCS-CDM project sites for the 20-year period subsequent to the end of
the crediting period (after which the risk of reversal is assumed to be zero)
69
. CCS-CDM project
activities also minimize the risk of non-permanence between the end of the project accounting
period and the end of the monitoring period through reserving 5% of accounted quantities to offset
any leaked emission. This, however, leaves unaddressed the risk of non-permanence of leaked
emissions beyond the 5% threshold.
Within the Paris Agreement, non-permanence has been fully addressed by requiring that “Parties strive to
include all categories of anthropogenic emissions or removals in their nationally determined contributions
and, once a source, sink or activity is included, continue to include it”
70
. In other words, any subsequent
reversal of results should be reported and accounted for (in the year in which it occurs).
Summary: Addressing the risk of non-permanence under the UNFCCC
Under the UNFCCC, the risk of non-permanence is fully addressed in accounting frameworks
through an assumption that reporting (through the NGHGI) and accounting (e.g. through the
Paris Agreement) will occur indefinitely;
For the land use sector, such a risk is further addressed by:
o ensuring that once a land/pools/activity is accounted, it must remain within the
accounting in perpetuity; and
o issuing temporary mitigation units that may be renewed so far as GHG emissions and
removals from accounted land/pools are monitored.
Under the Paris Agreement, permanence is addressed so long as land/pools/activities
accounted for in any NDC are accounted for in all subsequent NDCs.
68
The crediting period is the period during which achieved mitigation results are accounted and, if verified emission reductions have occurred,
mitigation units are issued.
69
However, it is recognized that, in the very long term, CO2 stored in deposits under oceans may have an impact on atmospheric CO2 by first
saturating sea water.
70
Decision 1/CP.21, para 31c. Considering that both land and C pools may be either a source or a sink, it may be implied that once a land or a C
pool is included in the NDC accounting it must be accounted forever.
23
8. Addressing the risk of non-permanence under other accounting frameworks
There are a number of other accounting frameworks, outside the UNFCCC, that have adopted approaches
to deal with the risk of non-permanence. The development of such approaches is necessary because of
the mismatch between the (short) timeframe of projects or programs seeking crediting and the (longer)
time horizon across which permanence of accounted results need to be ensured. Such approaches vary,
but are usually a combination of measures that:
Aim to reduce the risks of non-permanence when accounting over shorter time-frames:
o Program design requirements (e.g. to demonstrate transformational change)
o Insurance mechanisms (e.g. buffer accounts or pooled reserve)
Address non-permanence, such as:
o Requirements for monitoring for long periods
o Liability for reversal
Many programs include requirements related to program design, i.e. demonstration that the underlying
project or program that is generating emission reductions or removals has been designed to ensure long
term storage of C stocks. For example, the Forest Carbon Partnership Facility’s Carbon Fund requires
countries to demonstrate “how effective Emission Reduction Program design and implementation will
mitigate significant risks of reversals … and will address the sustainability of Emission Reductions.” The
Verified Carbon Standard also requires such ‘sustainable’ program design through the required
application of a “non-permanence risk tool” which scores a program based on a range of risk types and
does not allow high risk projects to proceed. In addition, the ratio of units required to be placed in the
buffer pool (see paragraph below) is determined by the project’s scoring on permanence risk, which
incentivizes the mitigation of reversal risks through good project design.
Most crediting or payment mechanisms (e.g. the Verified Carbon Standard, Forest Carbon Partnership
Facility’s Carbon Fund, California’s cap-and-trade system) require projects or programs seeking to issue
emission reductions (or credits) to establish a reserve of accounted units to be used to offset any
reversal. These are often pooled into a ‘buffer’ reserve or account which may then be used in the
instance of a reversal. Some accounting frameworks only allow the buffer to be used in the case of a
natural disturbance, or force majeure, event (while placing liability for ‘intentional’ reversals on the
project proponent or land owner). The number of units required to be placed in the reserve is estimated
based on an analysis of the likelihood of a reversal. For example, a risk analysis may be based on: lack of
broad and sustained stakeholder support, lack of institutional capacities and/or ineffective vertical/cross
sectorial coordination, lack of long-term effectiveness in addressing underlying drivers, the lack of
unambiguous assignment of carbon rights, the exposure and vulnerability to natural disturbances
(although the latter is not a cause of non-permanence so far as the disturbed forest is allowed to grow
again till its pre-disturbance status). Finally, a reserve account reduces the risk of reversals, but only
ensures permanence of units equivalent to the quantity of reserved units it contains since all reversals
exceeding such amount would not be offset—although such risks can be mitigated through a pool of
credits drawn from a diversified set of projects.
A few systems have more stringent rules to address permanence, through legal liabilities placed on
project proponents and/or land owners. California’s cap-and-trade system defines permanence as lasting
for 100 years. A forest carbon project must monitor, verify, and report offset project data for 100 years
following any year a credit is generated and issued. For example, if a credit is issued in year 25 of a
project, monitoring and verification would have to last for a total of at least 125 years. Furthermore,
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there is a regulatory obligation
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for all intentional reversals (e.g. from land conversion, over-harvesting or
other negligence) to be compensated through retirement of other compliance instruments
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. Similarly,
the Australian Emissions Reduction Fund requires any carbon uptake underlying issued credits to be
stored for at least 100 years—or 25 years with a 20% discount on credits. A land owner may choose to
cancel a project at any time but, in doing so, is required to relinquish all credits as well as use credits from
another project or purchase an equivalent amount at market price, to replace any credits already sold. In
both instances (California and Australia), these provisions are in addition to participating in a buffer pool,
i.e. projects are also required to place a percentage of emission reductions achieved into a reserve, which
is used only for ‘unintentional reversals’, primarily natural disturbances, while the project proponent or
land owner is fully liable for any intentional reversal.
Summary: Addressing the risk of non-permanence under other accounting frameworks
Other accounting frameworks have developed systems and tools to manage the risk of reversals:
Requiring projects or program to contribute to a buffer reserve account (a kind of pooled
insurance mechanism), particularly for use in ‘unintended reversals’ (force majeure events, e.g.
natural disturbances); such a mechanism only ensures permanence up to the number of units
in the reserve;
Requiring specific elements to be included in the project/program activity and/or design that
minimize the risk for reversals;
Or to address non-permanence:
Monitoring and verification for a long-term period considered to ensure permanence, e.g. up
to 100 years;
Providing clear liability for ‘replacement’ of accounted units for any instance in which a
reversal occurs.
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Regulation for the California Cap on Greenhouse Gas Emissions and Market-Based Compliance Mechanisms
https://www.arb.ca.gov/cc/capandtrade/capandtrade/unofficial_ct_100217.pdf
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If the forest owner does not provide offset credits for retirement equal to the reversal amount, then California’s Air Resources Board retires
the difference and the forest owner is considered in Violation of the regulation and subject to enforcement action.
