Global fossil fuel consumption continues to rise; decline in deforestation of the Amazon reduces Brazilian emissions
André Kitagawa
Global greenhouse gas (GHG) emissions hit a record high in 2023, at 57.1 billion tons of carbon dioxide equivalent (CO2eq). The figure is 1.3% higher than in the previous year, according to a report released by the United Nations Environment Programme (UNEP) at the end of October. The growth rate was higher than in the previous decade (from 2010 to 2019), when, before the outbreak of COVID-19, emissions rose by an annual average of 0.8%. In 2020, at the height of the pandemic, the suspension of many activities worldwide caused a drop of almost 5% in total emissions, the largest recorded since the 1970s.
This year’s increase in global emissions occurred in four of the five major GHG-producing sectors: energy, industrial processes, agriculture, and waste treatment. Only the land use, land-use change, and forestry (LULUCF) category released less greenhouse gases in 2023 than in the previous year. The process that most influences this sector’s emissions total is the removal of vegetation, especially clearing forests, to make way for agriculture and livestock.
“The problem in Brazil is that the national inventory underestimates carbon dioxide emissions from forest fires and degradation of vegetation,” points out Luciana Gatti, head of the Greenhouse Gas Laboratory (LaGEE) at the Brazilian National Institute for Space Research (INPE). Apart from agriculture, through which carbon can be stored in the soil but the removal of which is not usually accounted for in carbon inventories, the LULUCF sector is the only one that in addition to emitting can also naturally remove carbon dioxide from the air (other sectors only emit GHGs).
Alexandre Affonso / Pesquisa FAPESP
Well-preserved green areas can remove more CO2 from the atmosphere via photosynthesis, storing it in their biomass, than they emit through respiration. Due to its dense tropical vegetation, the Amazon has always been considered an area of the planet that absorbed more carbon than it emitted. Recent studies, such as the research carried out by Gatti’s team, indicate that due to deforestation and progressive degradation, parts of the Amazon are losing the capacity to provide this ecosystem service that reduces global warming (see Pesquisa FAPESP issue nº 321).
Today, most analyses indicate that the global temperature is at least 1.2 degrees Celsius (ºC) higher than the reference values of the preindustrial era, in the second half of the nineteenth century. Various studies have shown that this level of warming has led to a deterioration in some of the planet’s vital signs, such as rising sea levels and intensification of extreme weather events. Since 2023, however, a global temperature increase of 1.5 ºC has been recorded several months in a row, although it is still considered a temporary rise, for now (see Pesquisa FAPESP issue nº 343).
According to the UNEP report, there has been an increase in the emission of four gases that contribute to global temperature rise: carbon dioxide (CO2), which alone causes three-quarters of global warming, driven primarily by the burning of fossil fuels (oil, gas, and coal); methane (CH4), released mainly through agriculture and leaks during natural gas exploration; nitrous oxide (N2O), present in agricultural fertilizers and animal waste; and hydrofluorocarbons (HFCs), which are used in refrigeration systems.
André Kitagawa
In the statistics, emissions of methane, nitrous oxide, and HFCs are commonly converted into their equivalent in CO2. The established conversion formula states that in one century, the production of one ton of methane or nitrous oxide heats the atmosphere to the same extent as 25 or 298 tons of CO2, respectively. For HFCs, which encompass a family of artificially produced gases, the conversion factor often exceeds one thousand.
If the current upward trend in GHG emissions is not reversed, there is zero chance of limiting global warming to 1.5 °C, the target established by the Paris Agreement in 2015, and the global temperature will rise by an estimated 2.5 °C to 3 °C by the end of the century. This level of warming would be catastrophic, coming at a huge cost to human lives and the global economy. “To get on a least-cost pathway toward [limiting global warming to] 1.5 °C, emissions must fall 42% by 2030 compared to 2019 levels,” Danish economist Inger Andersen, UNEP’s executive director, said in the document’s foreword. Another way would be to reduce emissions by 7.5% every year from now until 2035.
Brazil’s emissions drop Unlike most of the planet, Brazil significantly reduced GHG emissions last year. According to the Greenhouse Gas Emissions and Removals Estimation System (SEEG), managed by a network of nongovernmental organizations known as the Climate Observatory, the country emitted 2.6 billion gross tons (not including removal) of CO2eq into the atmosphere in 2023, 12% less than in 2022. It was the biggest drop in the last 15 years.
The sector that contributed most to the country’s emissions was changes in land use (46%), historically the leader in GHG production in Brazil. Next was agriculture (28%), energy (18%), waste management (4%), and industrial processes (4%). With regard to net emissions (the gross total minus the carbon removed from the atmosphere by photosynthesis of growing vegetation), the amount of GHGs released into the atmosphere by Brazil in 2023 was around 1.6 billion tons of CO2eq.
Alexandre Affonso / Pesquisa FAPESP
The data from SEEG is not official, but it closely follows the methodology recommended by the United Nations Intergovernmental Panel on Climate Change (IPCC). “By the end of this year, we will create a new inventory of net greenhouse gas emissions [taking account of removals by the LULUCF sector] up to the period of 2022,” says Márcio Rojas, head of climate science, and sustainability at the Brazilian Ministry of Science, Technology, and Innovation (MCTI). “Our numbers are usually very similar to the net emissions figures calculated by SEEG, which uses the national inventory as a reference.”
The most recent information from the ministry’s National Emissions Registration System (SIRENE) relates to 2020, the year the pandemic began. Brazil emitted 1.7 billion tons of CO2eq that year, of which 38% was from the LULUCF sector and 28.5% was from agriculture, according to SIRENE. The energy, industrial processes, and waste management sectors accounted for 23.2%, 6.1%, and 4.2% of total GHG emissions respectively.
Brazil’s reduction in emissions in 2023 is due to the particular nature of its economic model. The country’s total GHG output was lower last year thanks exclusively to a 24% decrease in emissions by the land-use change sector. In the other four sectors that release carbon into the atmosphere (energy, agriculture, industrial processes, and waste management), emissions grew in Brazil in 2023, according to SEEG. “In Brazil, land-use change has historically dictated the dominant trend in the production of greenhouse gases,” explains David Tsai, a chemical engineer from the Institute for Energy and the Environment (IEMA) and coordinator of SEEG. “It is a kind of modulator, a regulator of the intensity of total emissions.”
Alexandre Affonso / Pesquisa FAPESP
In the major countries and blocs that currently emit the most GHGs into the atmosphere, such as China (30% of the total), the USA (11%), India (8%), the European Union (6%), and Russia (5%), the sector that accounts for the most greenhouse gases is, by far, energy. Despite recent advances in the use of wind and solar energy, the energy mix in these countries still relies heavily on the consumption of oil, gas, and coal. Thus, in these places and globally, the burning of fossil fuels is still the major driver of global warming. The USA remains the country that has emitted the most GHGs since the mid-nineteenth century, with around 20% of the total since 1850.
Brazil has a cleaner energy mix than other countries. More than 80% of its electricity comes from renewable sources, such as hydroelectric, solar, and wind power plants, and a significant proportion of the country’s vehicles run on biofuel. Despite this fact, depending on the year and the source consulted, the country is still the fifth or sixth largest current emitter, accounting for 2% or 3% of total GHG emissions. As a global leader in crop and cattle farming, the country produces a huge volume of GHGs through agriculture. In Brazil, this sector plays a greater role in total emissions than in most other major economies.
Tsai notes that a significant change in a single parameter in the land-use change sector was responsible for the decrease in total GHG emissions in the country in 2023: a significant drop in deforestation of the Amazon, the largest tropical forest on the planet, 60% of which is located in Brazil. Approximately 4,500 square kilometers (km2) of the biome were deforested in Brazilian territory in 2023, 62% less than the previous year, according to a report by MapBiomas, another Climate Observatory initiative.
André Kitagawa
The official data used by the Brazilian government in international negotiations also points to a recent and significant decrease in deforestation in the “Legal Amazon,” a political and administrative concept that encompasses almost 60% of Brazil’s territory, including the entire Amazon biome, 20% of the Cerrado (a wooded savanna biome), and a small area of the Pantanal. According to information released in early November by the Brazilian Amazon Deforestation Satellite Monitoring Program (PRODES), a project managed by INPE, 6,288 km2 of the Legal Amazon was deforested in 2024, 31% less than in the previous year.
“Deforestation trends, especially in the Amazon, have a major impact on the profile and volume of greenhouse gas emissions,” agrees Rojas, from the MCTI. Data from MapBiomas and PRODES generally point to the same major trend with regard to deforestation in the Amazon, although they cannot be compared directly due to methodological differences (see Pesquisa FAPESP issue nº 334).
The cleaner energy mix and the heavy influence of deforestation and agriculture on total emissions make Brazil a unique country on the international landscape of greenhouse gas production. Roughly three-quarters of emissions in the world’s largest economies result from activities and processes that depend on the burning of fossil fuels. In China, the USA, and the European Union, the LULUCF sector (and even agriculture) generally has a lower influence on the total amount of carbon emitted into the atmosphere.
Alexandre Affonso / Pesquisa FAPESP
During the 2024 United Nations Climate Change Conference (COP29), held in Baku, Azerbaijan, between November 11 and 22, Brazil announced a new commitment to reduce emissions in the period of 2030 to 2035. Known as the country’s nationally determined contribution (NDC), Brazil’s target for 2035 is to reduce net greenhouse gas emissions (taking into account carbon removal through forest maintenance) to between 59% and 67% of 2005 levels. In numerical terms, this would cut Brazil’s emissions to between 850 million and 1.05 billion tons of CO2eq per year.
The new NDC, one of the commitments required from all 196 signatory countries of the Paris Climate Agreement as part of the effort to limit global warming to 1.5 ºC, was considered complacent by many environmentalists. This opinion is not shared by Roberto Schaeffer, an engineer from the Alberto Luiz Coimbra Institute for Engineering Research and Graduate Studies at the University of Rio de Janeiro (COPPE-UFRJ). “The goal is very ambitious,” says Schaeffer, a professor on UFRJ’s energy planning program, whose team carried out the studies (not yet published) that supported the new NDC target at the request of the Brazilian government. “If we eliminate deforestation, emissions from the LULUCF sector will plummet rapidly, as will the country’s total GHG emissions as a consequence. When this happens, Brazil’s emissions profile will become more similar to other countries. From then on, we will also have to try even harder to reduce emissions from sectors other than LULUCF alone, while at the same time encouraging GHG removal through the preservation and restoration of forests.”
Once this new hypothetical scenario is established, Brazil would have a smaller carbon footprint, but it would also find it more difficult to continue drastically cutting its emissions. The reason is that the four other major sectors that produce GHGs (energy, agriculture, industrial processes, and waste management) respond much more slowly to changes designed to reduce their emissions. “Methane production by cattle, for example, will not decrease radically overnight, even if it is possible to partly reduce emissions resulting from enteric fermentation in livestock,” explains Schaeffer.
André KitagawaIt is still too early to tally the global GHG emissions data for 2024. However, the Global Carbon Budget (GCB), published annually since 2006, was released in November (not yet published in a scientific journal), providing an estimate of the year’s emissions of CO2 alone, not including other GHGs. The figures outlined in the 2024 GCB, often used as a reference, are cause for concern. Total carbon dioxide emissions are expected to set a new record of 41.6 gigatons by the end of December, 2.4% more than in 2023.
The severe droughts caused by the El Niño climate phenomenon in 2023 and 2024, one of which is still impacting the Amazon, have exacerbated emissions from deforestation and forest fires that degrade vegetation. “The impacts of climate change are becoming increasingly dramatic. yet we still see no sign that burning of fossil fuels has peaked,” said Pierre Friedlingstein, from the University of Exeter, UK, in a press release.
In the Brazilian Amazon, deforestation continued to fall this year. However, the number of forest fires in several biomes was very high, especially in the first half of the year, a period when there are not normally many fires. Due to this situation in Brazil, in addition to the global trend of emissions continuously increasing at a time when countries should be reducing their carbon footprint—as promised in previous NDCs—optimism is currently low. But giving up is not an option. We only have one habitable planet.
The story above was published with the title “Global rise, national fall” in issue 346 of December/2024.
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