Degradation of remaining forest can emit as much or more carbon than deforestation

Since the beginning of this century, the Amazon has lost around 30% of its capacity to retain carbon dioxide (CO2), one of the main greenhouse gases. If the current policy, which favors or even promotes deforestation and degradation of the remaining areas, is maintained, this capacity could reach zero by the end of the next decade, with the Amazon ceasing to be a sink and becoming a carbon emitter.

The alert was made by the researcher David Montenegro Lapola, from the Center for Meteorological and Climatic Research Applied to Agriculture at the State University of Campinas (Cepagri-Unicamp), in a webinar promoted by the Academy of Sciences of the State of São Paulo (Aciesp) to celebrate FAPESP's 60th anniversary.

In addition to deforestation, there is another impact factor, less known, which is the degradation of the remaining forest. “Considering degradation due to drought, degradation due to fire, degradation due to selective logging and degradation due to the so-called edge effect, 4% to 38% of the remaining forest is already degraded, with equivalent or even greater CO2 emissions. than in deforested areas,” said Lapola, emphasizing the need for a new development paradigm capable of reversing the course of destruction and saving the forest.

In March this year, at the 26th United Nations Conference on Climate Change (COP26), the Minister of the Environment, Joaquim Leite, declared that the Brazilian government had chosen to go beyond existing laws and policies and was committed to eliminating illegal deforestation of the Amazon by 2028. However, data released by the National Institute for Space Research (Inpe) indicates that, in the first half of 2022 alone, 3.971 square kilometers (km2) of the Legal Amazon were destroyed. Deforestation recorded in June this year was the highest for the month since the institute began monitoring in August 2015. Approximately 90% of this deforestation is illegal deforestation.

The most consistent studies show that containing global warming below 2 oC, preferably up to 1,5 oC, compared to pre-industrial levels, is the only way to avoid climate catastrophe. And this orientation was enshrined in the Paris Agreement, which came into force at the end of 2016. More than five years later, however, the data shows that we are heading towards an increase of 3 oC, with notable irresponsibility on the part of several governments and indifference of a large part of the population.

The implementation of the goals agreed in Paris depends on the Nationally Determined Contributions (NDCs, according to the initial letters of the expression in English) of each country signatory to the agreement. In the first version of the Brazilian NDC, still in 2015, the country assumed the goal of reducing its greenhouse gas (GHG) emissions by 37% by 2025 and by 43% by 2030, based on 2005 emissions. of the NDC, published at the end of 2020, these percentages were maintained, but the values ​​considered as a calculation basis were higher than those used in the original NDC. In other words, not only did the targets fail to improve, as would have been desirable, but a real increase in emissions was also embedded under the numbers presented. The promise made by the minister at COP26, to reduce GHG emissions by 50% by 2030, is therefore not supported by concrete measures.

The greatest threat in history

Entitled "Global climate change: its impacts and mitigation and adaptation strategies”, the webinar organized by Aciesp aimed to present and discuss the second chapter of the book FAPESP 60 Years: Science in national development.

The opening was made by Adriano Andricopulo, executive director of Aciesp, Luiz Eugenio Mello, scientific director of FAPESP, and Paulo Artaxo, member of the Intergovernmental Panel on Climate Change (IPCC), vice-president of Aciesp and member of the coordination of the FAPESP Research Program on Global Climate Change (PFPMCG).

In addition to Lapola, they participated as speakers Gabriela Marques Di Giulio, from the Faculty of Public Health of the University of São Paulo (FSP-USP); Pedro Leite da Silva Dias, from the Institute of Astronomy, Geophysics and Atmospheric Sciences (IAG) at USP; It is Mercedes Bustamante, from the Institute of Biological Sciences at the University of Brasília (ICB-UnB).

The human dimensions of climate change were the subject of Di Giulio's intervention, who addressed how societies should structure their public policies to respond to ongoing social risks. “There is a need for transformative changes in all dimensions – mainly for an urgent replacement of this predatory model of plundering nature with a model based on solidarity, respect for biological diversity and social justice”, stated the researcher, remembering that, currently , there are almost 35 million Brazilians without access to treated water and around 100 million without access to sewage collection.

“Another challenge is that of food security, at a time when Brazil is once again strongly present on the United Nations (UN) hunger map. There are more than 125 million Brazilians who are food insecure and more than 33 million who are hungry,” he said.

Silva Dias addressed the challenges of modeling given the extreme complexity of the climate system and anthropogenic influences. “There are two main ways to understand the mechanisms responsible for climate variability and the potential role of man: climate modeling of an extremely complex system and observational analysis of the period and past climate estimators, the paleoclimate. The two are complementary and must go together”, he said, highlighting that it is necessary to compare and select the best models, which are capable of reproducing the current climate well.

Bustamante associated two extremely important ongoing processes, climate change and the decline of biodiversity, highlighting that the increase of each fraction of a degree implies the intensification of extreme climatic events, with multiple risks, and that the impacts will be enormous if global warming exceeds 1,5 oC. “Global warming represents the greatest threat to biological diversity in human history,” he said.

The researcher recalled that Brazil has extraordinary environmental assets, which should be the opportunity for a new development agenda. Quite the opposite of what is being done.

The webinar “Global climate change: its impacts and mitigation and adaptation strategies” can be watched in full at: www.youtube.com/watch?v=0XEw7wATBWs.