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Acta Amazonica

Print version ISSN 0044-5967

Acta Amaz. vol.39 no.4 Manaus  2009

doi: 10.1590/S0044-59672009000400030

Global warming
in Amazonia: Impacts and Mitigation

Aquecimento
Global na Amazônia: Impactos e Mitigação

Philip Martin
Fearnside

Instituto Nacional
de Pesquisas da Amazônia - INPAC. P. 478. CEP 69.011-970 Manaus-Amazonas.
E-mail: [email-masked]

ABSTRACT

Global warming has
potentially catastrophic impacts in Amazonia, while at the same time maintenance
of the Amazon forest offers one of the most valuable and cost-effective options
for mitigating climate change. We know that the El Niño phenomenon, caused by
temperature oscillations of surface water in the Pacific, has serious impacts in
Amazonia, causing droughts and forest fires (as in 1997-1998). Temperature
oscillations in the Atlantic also provoke severe droughts (as in 2005). We also
know that Amazonian trees die both from fires and from water stress under hot,
dry conditions. In addition, water recycled through the forest provides rainfall
that maintains climatic conditions appropriate for tropical forest, especially
in the dry season. What we need to know quickly, through intensified research,
includes progress in representing El Niño and the Atlantic oscillations in
climatic models, representation of biotic feedbacks in models used for
decision-making about global warming, and narrowing the range of estimating
climate sensitivity to reduce uncertainty about the probability of very severe
impacts. Items that need to be negotiated include the definition of "dangerous"
climate change, with the corresponding maximum levels of greenhouse gases in the
atmosphere. Mitigation of global warming must include maintaining the Amazon
forest, which has benefits for combating global warming from two separate roles:
cutting the flow the emissions of carbon each year from the rapid pace of
deforestation, and avoiding emission of the stock of carbon in the
remaining forest that can be released by various ways, including climate change
itself. Barriers to rewarding forest maintenance include the need for financial
rewards for both of these roles. Other needs are for continued reduction of
uncertainty regarding emissions and deforestation processes, as well as
agreement on the basis of carbon accounting. As one of the countries most
subject to impacts of climate change, Brazil must assume the leadership in
fighting global warming.

Keywords:
Carbon, Climate change, Deforestation, Environmental services, Global warming,
Greenhouse effect

RESUMO

O aquecimento
global tem impactos potencialmente catastróficos na Amazônia, e, ao mesmo tempo,
a manutenção da floresta amazônica oferece uma das opções mais valiosas e
baratas para mitigar as mudanças climáticas. Nós sabemos que o fenômeno de El
Niño, causado por uma oscilação da temperatura da superfície da água no
Pacífico, tem impactos sérios na Amazônia, causando secas e incêndios
florestais, como aconteceram em 1997-1998. Oscilações de temperatura no
Atlântico também provocam secas severas, como em 2005. Nós também sabemos que
árvores amazônicas morrem, tanto do fogo como do estresse hídrico sob condições
quentes e secas. Além disso, a água reciclada pela floresta fornece chuva que
mantém as condições climáticas apropriadas para floresta tropical, especialmente
durante a estação seca. O que nós precisamos saber com urgência, por meio de
pesquisa intensificada, inclui como representar melhor o El Niño e as oscilações
no Atlântico, nos modelos climáticos, como representar as retroalimentações
bióticas nos modelos usados para tomada de decisão sobre o efeito estufa, e um
estreitamento da gama das estimativas da sensitividade climática (para reduzir a
incerteza sobre a probabilidade de impactos muito severos). Assuntos que
precisam ser negociados incluem a definição de mudança de clima "perigosa", com
os correspondentes níveis máximos das concentrações de gases de estufa na
atmosfera. Mitigação do efeito estufa tem que incluir a manutenção da floresta
amazônica, o que traz benefícios para o combate ao efeito estufa por meio de
dois papéis separados: diminuir o fluxo de emissões de carbono que
acontece em cada ano devido ao ritmo rápido do desmatamento, e evitar a emissão
do estoque de carbono na floresta restante que pode ser liberada de
várias maneiras, inclusive por causa da própria mudança climática. Barreiras
impedindo a recompensação da manutenção de floresta incluem a necessidade por
recompensas financeiras para ambos estes papéis. Outras necessidades são
continuar a redução da incerteza relativo às emissões e ao processo de
desmatamento, assim como também um acordo sobre a base da contabilidade do
carbono. Por ser um dos países mais sujeito aos impactos da mudança climática, o
Brasil tem que assumir a liderança na luta contra o aquecimento global.

Palavras-chave: Aquecimento
global, Carbono, Desmatamento, Efeito estufa, Mudança climática, Serviços
Ambientais

I.) THE ROLE OF
AMAZON FOREST IN GLOBAL WARMING

Climate change is a
threat to the Amazon forest and loss of the forest is a threat to the climate.
Land-use change in Amazonia produces globally significant emissions of
greenhouse gases such as carbon dioxide, methane and nitrous oxide (Fearnside,
2007a, 2008a, 2008b). Because each hectare of deforestation has a significant
net emission, reducing deforestation rates represents an avoided impact. The
potential value of this avoided impact is much larger than the value that can be
earned through traditional land uses such as the sale of timber and cattle,
which are based on destruction of the forest. Avoided deforestation is a means
of transforming the value of the forest's environmental services into a cash
flow that can be used to maintain both the forest and the human population that
defends it. Avoiding emissions of greenhouse gases represents the environmental
service that it is closest to becoming a significant source of income in
Amazonia, while maintaining biodiversity and water cycling are potential sources
of value over the long term (Fearnside, 2008c). Use of the value of the forest's
role in maintaining the global carbon balance depends on a reliable
quantification of the emissions caused by deforestation.

Global warming is a
grave threat to the world as a whole, and Brazil, including Amazonia, is one of
the places expected to suffer the most severe impacts if emissions of greenhouse
gases continue unchecked. It is therefore necessary to reduce the total global
emission from all sources, whether or not the sources count as "direct
human-induced emissions" that are the responsibility of any particular country
(Allen et al., 2009; Meinshausen et al., 2009).

II.) IMPACTS OF
GLOBAL WARMING IN AMAZONIA

A.) WHAT WE
KNOW

1.) El Niño impacts
in Amazonia

The key question
for Amazonia is the future of El Niño. The recent Fourth Assessment Report of
the Intergovernmental Panel on Climate Change (IPCC) finds agreement among
models on an increase in "El Niño-like conditions" with continued global warming
(Meehl et al., 2007, pp. 779-780). This refers to warm water in the
Pacific Ocean, which triggers El Niño. However, the report finds no agreement
among the models on El Niño itself, meaning the droughts and floods at different
locations around the world. El Niño is very difficult to model and should
obviously be a top priority. It is hard to get all the symptoms happening
simultaneously in a model, with rain on the coast of Peru, drought in Amazonia,
floods in southern Brazil, drought in Ethiopia and Borneo, etc. Our problem in
Amazonia is that we know from direct experience that whenever there is warm
water in the Pacific we have droughts and forest fires in Amazonia. If a climate
model shows the Pacific warming up and nothing happening in Amazonia, it means
that there is something missing from the model, not that we are safer here. The
link between warm water in the Pacific Ocean and droughts and forest fires in
Amazonia is demonstrated by the complete coincidence of these events in Amazonia
with past "El Niño-like conditions," for example in 2003, 1997 and 1982. El Niño
occurrence and impact is therefore an anchor in reality - it derives from direct
observation and does not depend on the results of climate models.

2.) Atlantic
oscillation

A previously
unappreciated climatic threat became apparent in 2005 when a devastating drought
struck Amazonia. Streamflows in tributaries on the south side of the Amazon
River were so low that boats could not navigate the rivers and riverside
communities were isolated from hospitals and other essential services. Forest
fires burned in Acre and in neighboring parts of the state of Amazonas, an
unprecedented event (Brown et al., 2006; Vasconcelos and Brown, 2007).
The forest lost biomass through stunted growth and increased tree mortality
(Phillips et al., 2009). The year 2005 was not an El Niño year; rather
than warm water in the Pacific there was warm water in the southern part of the
North Atlantic and colder-than-usual water in the northern part of the South
Atlantic. The warm water in the North Atlantic gave energy to Hurricane Katrina
that struck New Orleans that year. It also contributed to the Amazon drought by
causing more air to rise when the Intertropical Convergence Zone (ITCZ) reached
the area of warm water. The air at the ITCZ rises to an altitude of
approximately 1800 m, divides into northward and southward flows, and then moves
towards the poles by approximately 30º of latitude before descending to ground
level and returning towards the equator at low altitude, thus forming the Hadley
cell. When the air rises, its moisture content condenses and falls as rain, and
when the air later descends to ground level it is dry and desiccates the area
where it comes to earth. With more hot, humid air rising at the ITCZ in 2005,
there was also more cold, dry air coming down 30º farther south. With the
temperature gradient between warm water in the North Atlantic and cold in the
South Atlantic, the ITCZ was drawn further north than usual, and at the time of
year when the seasonal movement of the ITCZ was near its northern extreme, dry
air was descending over the headwaters of the Amazon tributaries on the southern
side of the basin (e.g,, Fearnside, 2006a; Marengo et al., 2008).

The warm water in
the North Atlantic in 2005 was the combined result of several factors. One was
the Atlantic Multi-decadal Oscillation (AMO), which produces warmer-than-average
water in this area at approximately 40-year intervals. However, this oscillation
explains no more than 11% of the anomalous temperature in 2005, whereas 50% of
the temperature increase could be directly attributed to global warming
(Trenberth and Shea, 2006). There was also a 22% indirect contribution from
global warming from the remains of an El Niño period in the preceding years. In
addition, the reduction of industrial air pollution in Europe and North America
resulted in less shielding of this area of ocean by aerosols (Cox et al.,
2008).

The north-south
temperature gradient in the Atlantic is significantly correlated with rainfall
in the southwestern portion of Amazonia, and in 2005 both the Atlantic gradient
and drought in southwestern Amazonia were at extreme levels (Cox et al.,
2008). Results from the Hadley Centre model indicate a tremendous increase in
the magnitude of the Atlantic temperature gradient and associated Amazon
droughts if greenhouse-gas emissions continue their current path (Cox et
al., 2008). The simulation results indicate that the probability of a
drought as severe as that of 2005 was 5% (1 year in 20) in 2005, but this would
rise to 50% (1 year in 2) by 2025 and 90% (9 years in 10) by 2060. The
probability of these droughts explodes if atmospheric CO2 exceeds 400
ppmv, a level only slightly higher than the 2009 level of 387 ppmv. Atmospheric
CO2 concentrations are rising at approximately 2.6
ppmv/year.

3.) Forest
dieback

The Amazon forest
is quite vulnerable to climate changes in the direction predicted to result from
continued global warming: higher temperatures combined with less rainfall,
including longer dry seasons. When temperatures are higher, trees need more
water just to survive. Trees in standing forest can be killed due to climate
variability in today's climate, as occurred in the 1997-1998 El Niño drought
(caused by warm water in the Pacific Ocean) and in the severe drought in 2005
(caused by warm water in the Atlantic). In addition to trees essentially dying
of thirst during droughts, the greater chance of forest fires starting and
spreading greatly increases the risk to the forest were the climate to change as
projected (Nepstad et al., 1999, 2001). Tropical forests are more
susceptible to fire than are other vegetation types because forest fires have
been so rare over the last millennia that the tropical-forest trees did not need
to evolve defenses against fire. Amazonian trees have thin bark, and when fires
occur the cambium is heated under the bark at the base of the trunk, and the
trees die. Trees in other biomes, such as the cerrado, have thick bark
and resist fire.

Various lines of
evidence indicate that Amazonian forest can succumb to these changes. In the
INPA/STRI Biological Dynamics of Forest Fragments Project north of Manaus, over
65,000 trees have been tagged and monitored; the study shows clearly that trees
die with much greater frequency near forest edges, where microclimatic
conditions are hotter and drier than in the interior of a continuous forest
(Nascimento and Laurance, 2004; Laurance et al., 2006). The same result
has been confirmed near Santarém by the "Seca Floresta" Project, which is a part
of the Large-Scale Atmosphere Biosphere Experiment in Amazonia (LBA). Plastic
sheeting was installed to intercept 60% of the throughfall in the forest over a
one-hectare plot, and tree mortality greatly increased (Nepstad et al.,
2007). Both studies found that large trees are the first to die, thus both
increasing the release of carbon and allowing canopy opening to further dry the
forest microclimate.

Unfortunately,
Brazil's official positions in this area have been to deny the problem: when the
IPCC released its report on impacts in April 2007, the Folha de São Paulo
reported that "Yesterday [5 April 2007] the Folha de São Paulo
[newspaper] found that the Brazilian delegation [to the Intergovernmental Panel
on Climate Change meeting in Brussels] objected to the final text of the summary
mentioning savannization of Amazonia caused by global warming" (Folha de São
Paulo, 2007). However, no less than four chapters of the IPCC report
highlight the danger of savannization in Amazonia and the summary for policy
makers was approved with the statement that "By mid century, increases in
temperature and associated decreases in soil water are projected to lead to
gradual replacement of tropical forest by savanna in eastern Amazonia" (IPCC,
2007a). The Brazilian delegation's position is symptomatic. Just as US President
George W. Bush denied the very existence of global warming, thereby freeing
himself of any onus to do something about the problem, the Brazilian
delegation's efforts to avert official recognition of the danger of
savannization in Amazonia has the effect of forestalling the need for the
Brazilian government to confront the problem, including containing deforestation
and reducing greenhouse-gas emissions.

4.)
Evapotranspiration and rainfall

Simulations
indicate that if over 40% of the original forest in Amazonia were cut and
converted to cattle pasture or soybeans, the rainfall in eastern Amazonia would
decline precipitously, especially during the dry season (Sampaio et al.,
2007). These changes in precipitation could lead to degradation of the remainder
of the forest in this area. Whether or not 40% deforestation is the "tipping
point," or threshold, the existence of such a threshold has long been suspected
and constitutes a strong argument for stopping deforestation (Fearnside, 1985,
1997). As of 2008 a total of 18% of the originally forested area in the Legal
Amazon region had been cleared (Brazil, INPE, 2009). However, no safe level of
deforestation exists below which there is no risk. Rather than a single "tipping
point," every tree that falls increases slightly the probability that
irreversible feedbacks will be set in motion and destroy the remaining forest.
This is a risk that Brazil and the world can ill afford.

B.) WHAT WE NEED TO
KNOW

1.) Modeling El
Niño

Although our
knowledge contains various gaps, it is important to emphasize that this fact
does not represent a valid reason for any delay in actions to fight global
warming. On the contrary, the existence of uncertainties means that we should be
reducing emissions of greenhouse gases even more in order to insure that the
worst-case scenarios do not become reality. This is the well-known
"precautionary principle," which should be applied to policies on global warming
but obviously isn't.

There are several
things we need to know fast. The various global climate models show widely
different results for some parts of the world, especially Amazonia. The Hadley
Centre model, from the UK Meteorological Office, shows a complete catastrophe,
with the Amazon forest being essentially wiped out by the year 2080 as a result
of heat and drought (Cox et al., 2000, 2004). Several other models show a
more modest but still serious drying in the Amazon, including the National
Center for Atmospheric Research (NCAR) model from the USA and the Max Planck
Institute model from Germany. Some others show little change, and one (the
Geophysical Fluid Dynamics Laboratory model from the USA) even showed (as of the
time of the 2007 IPCC report) an increase in Amazon rainfall (Kundzewicz et
al., 2007, p. 183), but subsequent improvements in the model have eliminated
this unrealistic behavior (Stephen M. Griffies, personal communication, 2009).
Given the importance of the question of what happens to the Amazon rainforest,
it is amazing that discrepancies of the magnitude still existing among models
have not been resolved. The Hadley Centre results were first published in 2000,
and subsequent refinements of their model have only reinforced the catastrophic
conclusion for Amazonia. Of the 21 models submitted to Phase 2 of the Coupled
Model Intercomparison Project (CMIP2) (http://www.pcmdi.llnl.gov/CMIP); Covey et al. (2003)
the HadCM3LC Hadley Centre model produced the best representation of the link
between "El Niño-like conditions" and Amazon droughts (see Cox et al.,
2004, p. 153). The Hadley Centre model is not perfect: it produces a present-day
climate in Amazonia that is hotter (Cândido et al., 2007) and dryer
(Huntingford et al., 2004) than the real climate. Establishment of a
"permanent El Niño" indicated by the Hadley model is the key feature leading to
the catastrophic result in Amazonia. However, the danger of savannization does
not depend on the Hadley Centre model proving to be the best representation of
future climate: an average of the results of 15 models indicates savannization
of eastern Amazonia as a consequence of continued global warming (Salazar et
al., 2007).

Linking El Niño to
global warming has tremendous moral and political implications, in addition to
the scientific ones. When El Niño killed 200,000 people in Ethiopia in 1982
there was an enormous outpouring of charity and sympathy, with rock stars
singing "We are the World" to attract donations for the victims. But the drought
was presented as an act of God that was nobody's fault in particular. It wasn't
your car or your deforestation that caused that disaster. But if the frequency
of El Niño is linked to global warming, then everything changes because
greenhouse-gas emissions have identifiable culprits. Contributions to global
warming can be quantified and allotted to countries and individuals.

2.) Biotic
feedbacks

There are several
important features that were left out of the models used by the IPCC that need
to be analyzed and included. One is the "biotic feedbacks," especially the
carbon that would be released from the biomass and from the soil if the Amazon
forest were to die and be replaced by grassland with scattered trees or,
alternatively, by a low-biomass woody second growth. Only half a dozen of the
over 20 models analyzed by the IPCC had the capability of simulating the biotic
feedbacks, but these features were switched off in order to make the simulations
of all models comparable. If these feedbacks are included the temperature in
2100 is 38% higher (Cox et al., 2004, p. 138). Amazonia is an important
part of this effect.

Biotic feedbacks
involve not only the carbon stock in forest biomass but also the stock in the
soil under the forest. When forest is replaced by grass, whether through
deforestation or climate-induced mortality, much of this soil stock is released
(Fearnside and Barbosa, 1998). In fact, even without loss of the forest cover
the increase in soil temperature from global warming has the potential to
release massive amounts of carbon to the atmosphere, forming an additional
positive feedback relationship with climate change (Fearnside,
2009a).

3.) Climate
sensitivity

Another important
topic is the matter of "climate sensitivity." This is the amount by which the
average global temperature at equilibrium would increase over the pre-industrial
average with the concentration of atmospheric CO2 at double the
pre-industrial level, a benchmark that would be crossed in approximately 2050
without mitigation. The "most probable" value for this is approximately 2.8ºC
and the assumption of climate sensitivity close to this value is the basis of
all of the model runs that generated the graphs and maps in the IPCC report's
summary for policy makers. The problem is that this "most probable" value for
climate sensitivity implies that there is a 50% chance that the real value is
higher than this, and it could be a lot higher. The point at which there is 95%
assurance that the real value is included is now believed to be about 6.2ºC
according to a reassessment in 2006, down from a previous assessment that was
substantially higher (Hegerl et al., 2006). There needs to be much more
scientific work on constraining the estimates of climate sensitivity, and much
more policy work on the implications of changes at the high end of the
range.

The relevance of
the more devastating results at the high end of the climate-sensitivity range
can be visualized by an example. In 1998 the Palace II apartment building in Rio
de Janeiro collapsed. For someone living in a building, the possibility that it
might collapse represents a catastrophe. If someone who lives in an apartment
building were to ask an engineer if the building will collapse and were to
receive the answer that "it is most likely that the building will stay
standing," would the apartment dweller be satisfied? This means that there may
be a 51% chance that the building will stay standing, but there could be a 49%
chance that it will collapse like the Palace II. The apartment dweller will
therefore not be satisfied with a 50% probability of the building remaining
standing, and will want an assurance of 99% or more. The same applies to the
climate change scenarios based on a climate sensitivity value that represents
the "most likely" outcome.

C.) WHAT WE NEED TO
NEGOTIATE

The United Nations
Framework Convention on Climate Change (UN-FCCC), better known as the "climate
convention," specifies the purpose of the Convention as preventing the
atmospheric concentrations of greenhouse gases from reaching levels that cause
"dangerous interference with the global climate system" (UN-FCCC, 1992, Article
2). Negotiation of the definition of "dangerous interference" is currently
underway.

The significance of
defining a maximum increase in global temperature, and the corresponding
permissible concentrations of greenhouse gases, is that the nations of the world
must achieve this global target, and it no longer matters where the emissions
are coming from. This gives Amazonia a substantial additional role in mitigating
climate change. Not only does the forest have a role from the large annual
emission provoked by deforestation, but the stock of carbon in the remaining
forest has a value beyond its potential for future deforestation. The stock of
carbon in the remaining forest could be released by climate change itself, and
not only global climate change from the greenhouse effect but also partly from
regional climate change resulting from loss of evapotranspiration as
deforestation proceeds.

Due to the
importance of the Amazonian forest to Brazil, it is very important that the
country use its diplomatic weight to press for a very low value as the
definition of this number. The definition of dangerous climatic change should be
at the most 2Â°C above the pre-industrial level. This is the value chosen by the
European Union as their definition of "dangerous" and is now endorsed by over
100 countries. Substantial uncertainty surrounds the equilibrium CO2
concentration to which this amount of warming corresponds, but it is in
the neighborhood of 400 ppmv of CO2 equivalent, including the effects
of the trace gases such as methane and nitrous oxide. Since the concentration of
CO2 alone is already at 387 ppmv as of 2009, and the trace gases
elevate the total effect to over 400 ppmv, the cuts in the global emissions will
have to be very large and fast (Hare and Meinshausen, 2006). Therefore, all
mitigation options need to be used, including both reduction in burning fossil
fuels and decrease in deforestation.

The forest is
already vulnerable, especially in the dryer areas near the eastern and southern
edges of the forest (Hutyra et al., 2005; Salazar et al., 2007).
Any further change in the direction expected from global warming increases the
risk of savannization. Because of delays within the climate system, warming
would continue for 20-30 years even if anthropogenic emissions were to halt
immediately. After that period, however, the difference in simulated global
temperatures is very great depending on what course emissions take over the
coming years (e.g., IPCC, 2007b). The course of future emissions depends
on international negotiations currently underway to define "dangerous
interference with the global climate system."

The delays in the
climate system mean that actions must be taken well before critical thresholds
are passed. Because of the tremendous mass of the oceans (and because water
vapor that evaporates is a greenhouse gas) the water continues to warm and
affect climate even after emissions are reduced: the result of a kind "inertia."
Controlling climate change is analogous to steering a large ship, which can take
kilometers to change course after the helm is turned. In the case of the
Titanic, the crew saw the iceberg before the ship hit it, but they couldn't get
the ship to turn fast enough. In the case of climate, we may foresee a
catastrophe occurring in model results after 2050, with the Amazon forest
drying, but if we wait until the last minute to reduce emissions it will be too
late.

III.) MITIGATION
BY AMAZON FOREST MAINTENANCE

A.) WAYS TO FIGHT
GLOBAL WARMING IN AMAZONIA

A wide variety of
mitigation options has been proposed in Amazonia, including plantation
silviculture (including charcoal production), agroforestry, forest management
for timber, reduced-impact logging, soil carbon enhancement (including charcoal
additions, no-till agriculture and pasture fertilization), and, most recently,
biofuels (including oil palm). However, tapping the native forest's role in
mitigation is by far the best both in terms of carbon benefits (Fearnside, 1995)
and social and environmental concerns (Fearnside, 1996, 2006b). This discussion
will be limited to the maintenance of standing forest.

Deforestation can
be reduced by a variety of means, including command-and-control programs using
inspections and fines, creation of protected areas of a variety of types
(including "sustainable use" areas), various kinds of integrated development
projects aimed at channeling labor and capital resources to sustainable land
uses in deforested areas instead of clearing forest, direct payment for
environmental services, and policy measures affecting infrastructure
construction, agricultural credit, land-tenure and taxation. Environmental
agencies such as the Brazilian Institute for the Environment and Renewable
Natural Resources (IBAMA) only have access to some of these options, such as
command-and-control measures, reserve creation and payment for environmental
services.

It cannot be
overemphasized that infrastructure decisions must be an integral part of efforts
to control deforestation, rather than being separate as at present. Today major
highways and other developments are, in practice, decided by decree based on
political considerations, and the role of environmental agencies is restricted
(in practice) to legalizing the construction process and suggesting small
changes to minimize impacts. This must change such that a full evaluation of
impacts, including resulting deforestation and climate impacts, are considered
before decisions are made on building the infrastructure (e.g.,
Fearnside and Graça, 2006; Fearnside, 2007b). In order for the deforestation and
emissions impacts of individual infrastructure decisions to be quantified (and,
conversely, the benefits of the "no project" option), one must have
deforestation models with realistic provisions for the stimulation effect of
roads on deforestation and the percentage of "leakage" when deforestation is
inhibited by reserves and other measures. "Leakage" refers to effects a
mitigation project provokes outside of its boundaries that cancel out all or
part of the climatic benefits of the project itself, for example if people who
would have deforested in a protected areas simply move somewhere else in the
forest and continue clearing. Existing models for regional deforestation
(e.g., Soares-Filho et al., 2006) do not yet have this capability,
but progress has been made towards enhancing these models to simulate the
effects of individual decisions (Fearnside et al., 2009). This opens the
possibility of much more effective proposals for capturing carbon credit through
avoided deforestation, as well as providing a tool for improved decision-making
on infrastructure.

B.) BARRIERS TO
REWARDING FOREST MAINTENANCE

If keeping
Amazonian forest standing is to assume a role in strategies to mitigate global
warming one must look at what has so far prevented this from happening and then
address these issues. The forest really has two separate roles with respect to
global warming: the flow of carbon to the atmosphere represented by
annual emissions from clearing (which can be reduced through avoided
deforestation), and the stock of carbon in the standing forest.
Deforestation activity in Amazonia is spatially highly concentrated, over 80% of
it occurring in the "arc of deforestation" along the eastern and southern edges
of the forest. In this area a system of rewarding avoided deforestation could be
established where emissions are compared to a baseline (presumably based on the
recent history of clearing). This is what is implied by the Kyoto Protocol under
what is commonly known as "additionality," or what is additional as compared to
what would have happened in the absence of a mitigation project. In parts of the
region where little or no deforestation has taken place, a different system of
rewarding environmental services is needed based on stocks. Clearly the role of
the forest in mitigating global warming will only be tapped if the way that the
reward is calculated for each location results in a reasonable
return.

Brazil's diplomatic
community has traditionally resisted the idea of rewarding the Amazon forest's
climatic role under the UN-FCCC (e.g., CFR Independent Task Force. 2001;
Fearnside, 2001). This has its root in a lack of confidence that Brazil's
government is capable of controlling deforestation, the implication being that
were Brazil to agree to reduce emissions by a given amount and then find that
deforestation could not be reduced as promised, the country would (in the view
of these people) be exposed to pressures that would interfere with Brazil's
sovereignty in Amazonia. The solution to this is an unambiguous demonstration
that the government can control deforestation if it is serious about doing so.
Several lines of evidence indicate that the government has this ability
(Fearnside, 2003; Fearnside and Barbosa, 2003).

A different set of
concerns has been raised by various national governments and other entities that
are committed to designing a system of mitigating global warming that is
sufficiently reliable to be used as credit against emissions from fossil fuels.
These include the level of uncertainty associated with each hectare of
deforestation that is avoided and uncertainty as to how many hectares have been
avoided (see Fearnside, 2000). Both require improvements of data and of
monitoring capabilities. Much has improved in both respects. We at INPA have
made significant progress in better quantifying the carbon stocks in the forests
being cleared, in accounting for the emissions and uptakes that occur after
clearing, and in modeling the process and distribution of deforestation. In
addition, the large amounts of emission that can be avoided at relatively low
cost mean that uncertainty can always be more than compensated for by granting
less credit than the amount of physical emission believed to be avoided. In
addition to these concerns over the data used in carbon accounting, there are
also disagreements over the theoretical basis of the accounting itself,
particularly with regard to "permanence" (the time the carbon remains out of the
atmosphere), or more generally the value attributed to time (Fearnside, 2002a,
2002b; Fearnside et al., 2000) and leakage (Fearnside, 2009b). Several
proposals exist to address these problems, including proposals generated at
INPA. Lastly, negotiations for rewarding environmental services must address the
question of what is to be done with the money such that it ensures attainment of
both objectives: maintaining the forest with its environmental services and
maintaining the wellbeing of the human population in the Amazonian
interior.

C.) BRAZIL MUST
ASSUME LEADERSHIP

Brazil is one of
the countries of the world with the greatest expected impacts from global
warming (Dias et al., 2007; Fearnside, 2008d; Magrin et al.,
2007). In addition to massive mortality of the Amazonian forest, other parts of
the country would also be affected. In the Northeast global warming would cause
drying in an area that already suffers constantly from lack of rain. In the
South it would increase torrential rain events and typhoons. Sea-level rise
affects the entire coast where much of the country's population lives.

Brazil must make a
quantitative commitment to reduce deforestation. It is important that this be
under the climate convention, as opposed to internal commitments that might be
rewarded through voluntary funds outside of the Kyoto process, as proposed by
Brazil at the conferences of the parties in Nairobi, Bali and Poznan in 2006,
2007 and 2008 (e.g., Brazil, 2006; Brazil, Comitê Interministerial sobre
Mudança do Clima, 2008). If the industrialized countries decide to fight global
warming in a serious way, agreeing in large cuts in their emissions under the
climate convention, all of their resources will be used to meet their negotiated
targets and nothing will remain for voluntary funds.

At the United
Nations meeting on climate change, held in Vienna in August 2007, the Brazilian
representative repeated the country's position since the 1992 "Earth Summit"
(ECO-92) of avoiding any quantitative commitment regarding emissions (O
Estado de São Paulo, 2007). Undoubtedly, Brazil can choose to continue to
resist taking on a commitment for a few more years, but sooner or later it will
be forced to make a commitment if global warming is to be controlled. It is in
Brazil's national interest that such a change of position be made now rather
than later. Brazil must assume the leadership in the fight against global
warming.

ACKNOWLEDGEMENTS

The Conselho
Nacional do Desenvolvimento Científico e Tecnológico (CNPq: Proc. 306031/2004-3,
557152/2005-4, 420199/2005-5, 474548/2006-6), Rede GEOMA and Instituto Nacional
de Pesquisas da Amazônia (INPA: PRJ05.57) contributed financial support. The
portion of this text on mitigation was presented as a discussion paper for
INPA's Grupo de Estudos Estratégicos Amazônicos (GEEA).

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Recebido em
26/11/2007
Aceito em 16/06/2009

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