- Brazil is reporting its CO2 emissions within U.N. guidelines, but those rules ignore significant sources of national greenhouse gas emissions ¬by disregarding carbon emitting processes related to forests, say scientists. None of this underreporting is likely unique to Brazil, but it is perhaps more acute there than in other nations due to Brazil’s vast forests.
- The U.N. doesn’t require Brazil and other developing nations to count certain greenhouse gas emissions in detail, especially sources it classifies as non-anthropogenic. This, for example, includes CO2 released from wildfires. However, most fires in the Brazilian Amazon are set by people clearing land, so those CO2 emissions are largely human-caused.
- Forest degradation, methane emitted from reservoirs, and carbon released from soils where forests are converted to croplands or pastures go partly or totally untallied in emission reports, sometimes because data is lacking, or because the UN hasn’t included the source in its reporting criteria. Another problem: low-resolution satellite monitoring allows small-scale deforestation to go undetected, so is unreported.
- As a result, Brazil’s actual carbon emissions are almost certainly higher than the figures reported to the United Nations — how much higher is unknown. But, experts say, that if this missing carbon were added to Brazil’s reported emissions, the nation would likely not meet its 2025 Paris Climate Agreement goal.
Brazil is likely underestimating its actual emissions of carbon and other greenhouse gases in its reported United Nations statistics, say scientists interviewed by Mongabay. If this missing data were included in official reporting, they add, it would show Brazil unlikely to meet its Paris Climate Agreement carbon reduction commitments.
Low-resolution satellite forest surveys and overlooked sources of emissions, especially those due to forest degradation and wildfires, mean that Brazil’s reported national greenhouse gas emissions statistics may be too low.
Experts note that Brazil is likely meeting United Nations guidelines in its reporting. However, those U.N. rules ignore significant sources of national greenhouse gas emissions by disregarding carbon emitting processes related to forests. None of this underreporting is likely unique to Brazil, but it is perhaps more acute there than in other nations due to Brazil’s vast Amazonian forests.
The challenges of counting carbon emissions
As part of the 2015 Paris Climate Accord, now ratified by 175 countries, Brazil pledged to reduce its national greenhouse gas emissions by 37 percent by 2025, relative to 2005 levels. This means reaching annual total emissions of 1.3 gigatons of CO2 equivalent within seven years.
Official reports suggest the country is on track to meet these obligations – the national total reported for 2012 was 1.2 gigatons – but scientists say key sources of emissions are going unreported or underestimated.
The UN Environment Programme’s Emission Gap Report published in October 2017 stated that, “recent studies assessed suggest that Brazil… [is] likely to – or [is] roughly on track to – achieve [its] 2030 Nationally Determined Contribution (NDC) targets with currently implemented policies.”
However, the Climate Observatory, a national civil society network, using its Greenhouse Gas Emissions Estimates System, known as SEEG, contradicted the UN’s assertion. The Climate Observatory found that Brazil’s greenhouse gas emissions rose nearly 9 percent from 2015 to 2016, and have reached their highest level since 2008.
“Many informed scientists think that Brazil is seriously underestimating its annual carbon emissions,” says Bill Laurance, Director of the Centre for Tropical Environment and Sustainability Science at James Cook University in Queensland, Australia. The country is “grossly underestimating the impacts of forest degradation,” he says. Full disclosure: Laurance serves on the Mongabay board.
So even though Brazil may be meeting its official obligations under the UN’s carbon reporting framework, a variety of causes including deforestation, forest degradation, and wildfires are going partly untallied and adding significantly to atmospheric carbon, and to global warming. The Brazilian government did not immediately respond to requests for comment for this story.
Low resolution monitoring misses the mark
One of the primary drivers of Brazil’s greenhouse gas emissions is land-use change due to deforestation: major ongoing losses in forest cover caused by a national and global demand for timber, beef, soy, cotton, corn, and other agribusiness commodities, and to a smaller extent, due to subsistence slash-and-burn agriculture.
In 2016, according to the Climate Observatory, the lion’s share of Brazil’s carbon dioxide equivalent emissions (51 percent) came from land-use change — an increase of 23 percent over 2015. Another 22 percent of CO2 equivalent emissions arose from agribusiness itself.
As part of its Paris Climate Agreement commitment, Brazil has pledged to put an end to illegal deforestation by 2030 and restore 120,000 square kilometers (46,332 square miles) of forest. But will this be sufficient to offset the nation’s rising uncounted carbon emissions?
That’s a very hard question to answer because how one measures and what one measures, can result in substantially different totals. “Estimating emissions and absorption of greenhouse gases caused by land-use change is hugely complex for a country of continental dimensions such as Brazil,” explains Mercedes Bustamante, a plant ecologist at the University of Brasília.
Official Brazilian estimates of deforestation and the emissions associated with it – reported to the United Nations Framework Convention on Climate Change (UNFCC) in 2017 – were based on satellite data collected by the Programa de Cálculo do Desflorestamento da Amazônia (PRODES). When that system was implemented in 1988, Brazil was hailed as a pioneer in deforestation monitoring, and its multi-decade continuous dataset for the Amazon rainforest is a powerful benchmark against which to evaluate change.
However, there is a problem. PRODES calculations are based on data from Landsat 7 and other satellites that operate with a comparatively low resolution, and so are only able to detect deforested plots larger than 6.25 hectares (0.025 square miles). “Brazil deserves much credit for being a world leader in monitoring deforestation,” states Laurance, but “field research and newer remote-sensing methods are revealing that lots of additional carbon is being lost from forest degradation and small-scale forest loss.”
PRODES has another problem: it ignores the logging of Brazil’s forests beyond the Amazon rainforest, such as the remnant coastal Atlantic Forest or the Caatinga dry forest. It also doesn’t measure any loss of secondary forest when estimating the scale of Brazilian deforestation.
“[For] any given area of forest, the changes in carbon storage may be small. But scaling those changes across thousands of hectares results in large carbon fluxes,” explains Ted Feldpausch, a University of Exeter tropical forest ecologist.
This shortcoming has likely caused PRODES to significantly underestimate the true rate of deforestation in Brazil, say scientists consulted for this article. A 2016 study used estimates of forest loss based on high-resolution satellite data collected by the Global Forest Cover Change Project and NASA’s Fire Information for Resource Management System. The results: researchers found that PRODES missed 9,000 square kilometers (3,475 square miles) of deforested land in the Brazilian Amazon between 2008 and 2012.
But Brazil is unlikely to upgrade its deforestation monitoring system any time soon, partly due to an understandable desire for a continuous comparable dataset down to the present: “The value of Brazil’s deforestation monitoring, despite its flaws, is that it uses a consistent methodology that allows one to make comparisons of annual deforestation rates. They’ve been doing this since 1989 and it is a unique and tremendously valuable tool,” says Laurance.
What could be done, he adds, is to incorporate data from the Sentinel-1 satellite into Brazil’s computer models to produce a more accurate estimate of emissions resulting from current land-use change.
Forest degradation, another source of missing emissions
Brazil made major strides in reducing deforestation in the early 21st Century, though the latest estimates show that rates have begun to rise again. However, counting only deforestation as a carbon source misses a second significant emissions driver: forest fragmentation and degradation.
“Brazil is a global leader in monitoring of forests and its annual assessments of deforestation are very impressive,” says Tim Pearson, a carbon specialist at environmental NGO, Winrock International. But the country “has mostly focused just on deforestation which will miss significant numbers from sources of forest degradation.”
Forest degradation – a process much more difficult to track than wholesale deforestation – is a significant contributor to greenhouse gas emissions in nations harboring large reserves of tropical forest. “Emissions from degradation have been unreported by Brazil,” agrees Paulo Moutinho, co-founder of the Amazon Environmental Research Institute (IPAM) in Brazil.
Scientists note that every forest patch that is logged, and every logging road that is built, creates new forest edges – a fragmented and fundamentally different environment to that of the deep forest interior. As of 2007, more than 50,000 kilometers (31,000 miles) of new forest edge was being created in Brazil each year. This in turn causes changes in vegetation that often emits more carbon than forest interiors. The survivability of these “edge effects” are highly variable; A 2007 study by Laurance and colleagues found that the fate of forest edges depends on the incidence of droughts and windstorms. But edge expansion clearly has an additive effect on forest degradation, and on carbon emissions.
Likewise, selective logging is being carried out via legal reduced-impact logging schemes, or being conducted illegally to steal valuable tree species in conserved areas and elsewhere. Logging is particularly difficult to track via satellite, but the damage caused to surrounding forest habitat when individual trees are extracted can result in more carbon emissions than the timber removal itself.
“Some of the largest uncertainty comes from detecting and estimating changes in carbon storage in forests that are not fully deforested, but instead have had increased tree mortality or are degraded in some way,” says Feldpausch. According to one study, between 1999 and 2002, emissions from selective logging represented between 60 percent and 123 percent of the total reported emissions from deforestation in Brazil’s top five Amazon timber-producing states – Pará, Mato Grosso, Rondônia, Roraima, and Acre. These states account for 90 percent of all deforestation in the Brazilian Amazon.
“My gut sense is that Brazil’s estimates of Amazon carbon losses from deforestation and forest degradation are being underestimated by roughly 50 percent,” says Laurance.
Drought and fire: more uncounted emissions
Brazil’s national carbon statistics, while following official UN guidelines, also ignore other major emission sources. Drought, for example, has been increasing in frequency and severity across the nation, leading to increased tree death, which releases CO2 and which can temporarily turn the Amazon carbon sink into an emission source. Scientists believe this shift is being driven by a combination of lower precipitation in the Amazon basin due to climate change, along with large-scale deforestation, which has also been found to reduce rainfall.
Current official reporting does not tally carbon emissions caused by tree death due to drought, as it is not considered a direct human source of emissions by the United Nations.
Drought-killed vegetation makes perfect kindling in dry conditions, increasing the risk of forest fires, that in turn release huge quantities of carbon to the atmosphere. But dry wood isn’t enough to start a blaze: most wildfires in the Amazon have a human source of ignition, and are routinely set by local labor paid by wealthy elites to clear forest tracts to create new cattle pasture and cropland. Those initially controlled fires can easily spread to neighboring forests, sparking uncontrollable wildfires. Though many of these fires originate via human activity, the UN still classifies them as non-anthropogenic – non-human caused.
Brazilian forests are estimated to hold as much as 269 milligrams of carbon per hectare, much of which is released if a forest burns. Research recently published in Nature Communications by Luiz Aragão of the National Institute for Space Research (INPE) and his colleagues estimated that forest fires in the Brazilian Amazon currently contribute annual emissions of 454 megatonnes of carbon dioxide per year, based on data from 2003 to 2015, and represent roughly one third of the estimated emissions from deforestation.
However, the Brazilian government does not count or report carbon released from wildfires in its annual totals, nor is it required to do so by the United Nations. According to Moutinho: “The biggest unreported sources of GHG [greenhouse gas] emissions in Brazil is related to the forest fire, especially in the Amazon region.” The wildfire carbon contribution is “potentially huge, especially during El Niño years.”
The El Niño Southern Oscillation is a weather pattern that pushes warm water to the central Pacific Ocean and South American equatorial coast, occurring on average every four to seven years. El Niño tends to alter trade winds and reduce rainfall in the Amazon region, and the phenomenon was linked to large-scale droughts there in 2010 and 2015. As climate change induced droughts worsen, they dry out forests, making once nearly fire-proof rainforests increasingly susceptible to wildfires, which means more carbon released.
Neither Brazil’s 2005 baseline carbon calculations, nor its 2025 Paris carbon reductions goals, account for increased numbers of Amazon wildfires as the world grows warmer. What is clear, Aragão says, is that focusing alone on curbing deforestation won’t be enough to reduce emissions. “Wildfires driven by droughts are likely to be more common,” he suggests, citing the cumulative impacts of extreme drought, forest degradation, selective logging and the use of fire to manage pasture and croplands.
Accurate, up to date wildfire carbon emission data is absolutely key if policymakers are to execute realistic and effective emission reduction strategies. “Brazil needs urgently to focus on incorporating into estimates, CO2 losses associated with fires unrelated to the deforestation process,” Aragão says.
The scientist does, however, credit his country’s past efforts to cut emissions: “Brazil has started doing the homework by reducing deforestation rates by 76 percent over the past 13 years,” he emphasizes. However, “Policies in place to reduce deforestation are not favoring the reduction of forest fires and consequently not being fully efficient in mitigating carbon emissions from the Amazon.”
According to Aragao’s research, wildfires in the Brazilian Amazon release 1,000 megatonnes of carbon dioxide during drought years, more than twice the estimates for non-drought years. These releases need to be counted into Brazil’s official Paris pledge totals if those tallies are to become more accurate, say experts.
Other sources of carbon underreporting
Greenhouse gas emissions remain a problem even after forests burn or are cut. That’s because regenerating forests don’t always return to their former state, so don’t store as much carbon as original old growth. Also, wildfires can stimulate vegetation changes that alter an ecosystem’s carbon balance. “The effect of fire on ecosystem carbon loss is further increased by fire-stimulated biological invasions, such as bamboo,” explains Philip Fearnside from the National Institute for Research in the Amazon.
Similarly, human activities such as dam building can fundamentally alter plant communities and release more carbon dioxide and other greenhouse gases such as methane, but the UN has yet to release standardized guidelines for estimating the extent of these emissions; also reporting these types of emissions is voluntary.
“Brazil’s large and growing network of hydroelectric dams may be a significant unreported source of GHG emissions,” says Marcia Macedo from the Woods Hole Research Center in Massachusetts U.S. Although Brazil has historically considered hydroelectric projects as a green source of energy, “there is a growing body of evidence that these dams produce and release a significant amount of methane,” a greenhouse gas more than twenty times more powerful than carbon dioxide.
Much of that methane comes from decomposing plant matter submerged by reservoirs, and from bacteria living in the sediments, but there are other less obvious sources too. For instance, many tree species – storing large amounts of carbon – were unable to survive on hundreds of islands created in the Balbina mega-dam reservoir on the Uatumã River in Amazonas state. But liana vines, which hold considerably less carbon, thrived, resulting in a net release of carbon into the atmosphere. It seems likely similar processes may be occurring at dam sites across Brazil.
Another major source of emissions that experts say has been underestimated in national statistics are those coming straight from the ground itself due to escalating climate change.
Decomposition of organic matter in the soil releases carbon, but this process can be accelerated if the soil is warmed or disturbed, while in a well-managed environment soils can become a net carbon sink. “We’ve come a long way in quantifying net emissions from annual cropping and ranching cycles and instantaneous emissions from biomass burning during deforestation,” explains Macedo, but there remains “a great deal of uncertainty about the total below-ground carbon stocks of tropical soils and the timing of losses after land conversion.”
Increasingly, evidence suggests that there can be a lengthy delay between land-use change and consequent greenhouse gas emissions from soil – native vegetation converted into sugarcane plantations, for example, can take eight years to pay out the carbon to the atmosphere stored in slow decaying roots and woody branches.
Hyper-focus on the Brazilian Amazon’s role in emissions, has also resulted in neglect of emissions from other parts of the country, especially the Cerrado. This tropical savanna habitat found to the east and south of the Amazon includes trees, shrubs and grasses that devote a lot of energy to root production – meaning that these scrub and shrublands store large stocks of carbon below ground.
But the loss of these carbon stores as Cerrado habitat is deforested and degraded and turned to cropland has not been included in the country’s emission tallies in the past, and so has been historically underestimated in national inventories, something that has become more crucial as the region’s native vegetation has been rapidly converted by industrial agribusiness. More than half of the Cerrado’s 2 million square kilometers (772,204 square miles) has already been converted to croplands and pasture.
The Third National Communication of Brazil to the United Nations Framework Convention on Climate Change, published in 2016, did finally address this issue, says Macedo. “One big improvement [of the third report] over the last inventory is a much more careful treatment of variations in aboveground carbon stocks across different vegetation types, particularly in the Cerrado,” she says.
The urgent need for better carbon accounting
The scientists interviewed for this story all came to a similar conclusion: with so many unknowns, uncertainties and uncounted emissions, Brazil’s hopes of honestly meeting its 2025 commitment to the Paris Climate Agreement seem slim.
“I’m not very optimistic at this point, [especially] given the huge governmental problems going on in Brazil,” says Laurance. The country’s extremely unpopular Temer administration and the National Congress – both plagued by roiling corruption scandals – continue in their strenuous efforts to undermine environmental and indigenous protections that will only escalate Brazil’s carbon emissions. National elections scheduled for October add to unpredictability.
Some uncertainty is inevitable when calculating greenhouse gas emissions, but where more precise measuring techniques and datasets are available, these should be incorporated to make national estimates as accurate as possible, say experts. Also, the UN should consider revamping its greenhouse gas emission evaluation standards, widening those guidelines to include the myriad ways in which forests release carbon. Such a change would not only make Brazil’s emissions tallies more accurate, but also those of forested nations around the globe.
The bottom line: Brazil may be meeting all of the United Nation’s carbon counting guidelines. And using current reporting criteria, the nation may even meet its Paris pledge for 2025. But nature knows exactly how much greenhouse gas is being released to the atmosphere by Brazil – and by all of the world’s nations – and nature will respond accordingly.
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