Deforestation impact on the Amazon Carbon Balance 2010-2022 and on climate change

Amazonia is the world’s largest rainforest and has proved to be an important carbon sink in the recent past. This carbon sink is decreasing, mainly due to increase tree mortality. The Amazon Forest contains about 90 PgC in aboveground and belowground vegetation biomass, which can be quickly released. The relationships between forest ecosystem, water cycles, and climate are complex. Estimates indicate that forest evapotranspiration is responsible for up to 50% of water recirculation. Hydrologically, Amazonia is one of the three main air upwelling regions in the tropics and the whole basin precipitation is about 2,200 mm per year. Over 13 years we carried out 893 aircraft vertical profiles and here we will present not only Amazon Carbon Balance for this period, but what we learned about the factors that affect its balance and the forest function, and why Amazon has become a carbon source. We studied 4 Amazon vertical profiles sites that represents the regions: northeast (SAN: 2.9°S, 55.0°W), southeast (ALF: 8.8°S, 56.8°W), southwest (RBA: 9.4°S, 67.6°W) and northwest (TAB 2010-12: 6.0°S, 70.1°W; TEF 2013-21: 3.4°S, 65.6°W; CZS 2022: 7.0°S, 72.5°W). Separating Amazonia into eastern regions (SAN and ALF) and western regions (RBA and TAB_TEF_CZS) we observed notable differences. The eastern region, approximately 30% deforested, presented 30% losses in precipitation during dry season in the last 4 decades, and an increase of 2.5°C in temperature, and carbon emission 8 times greater than western region, which is approximately 10% deforested. The loss of forest through deforestation, fires and forest degradation is impacting the Amazon carbon emission, and climate in the region itself, reducing rainfall and increasing temperatures, especially during the dry season. This process affects the remaining forest, promoting climate stress and thus reducing carbon removal from the atmosphere.