Impacto das queimadas em área de floresta no sul da Amazônia: uma reflexão ensaística sobre a precificação de carbono

Abstract

Tropical forests are important global climate regulators. They store notable amounts of carbon in their living biomass and maintain a delicate biosphere-atmosphere relationship. Exogenous and endogenous factors need to be in perfect harmony for this relationship to work properly. Carbon cycling in the Amazon has been extensively studied due to changes in CO2 concentrations globally, in soil, water, and mainly in the atmosphere. This research aims to contribute by identifying anthropogenic disturbances (burning of forest biomass) and their influence on the net exchange of CO2 in a semi-deciduous forest area south of the Amazon basin. In situ micrometeorological measurements, located 50 km NE of Sinop-MT, are used to estimate the CO2 absorption potential under polluted (AOD ≫ 0.10) and unpolluted (AOD ≤ 0.10). Limitations, uncertainties, weaknesses, and physiological optima are determined and used as key subsidies for approaches concerning carbon pricing in Brazil. Remote orbital data from the MODIS sensor (AODm) and surface data from the AERONET 2.0 system (AODa) given a regional view of the impacts of the fires on the flow of solar radiation. We have used a long series of AODa measurements between 1997 and 2017 in determining a clear-sky solar irradiance model. Here, we’ve observed reductions and increases in %NEE for given pollution loads (AOD), relative irradiance f, and solar zenith angle (SZA). The results show a 40 % in f consistent with a significant increase in pollution loads (AODa) from 0.10 to 5.0 nos at 500 nm. We also observed an average increase of 35-70 % in NEE flux for AODa pollution levels above 1.25. We’ve attributed these increases to the increase of 40-60 % in the diffuse fraction of solar radiation (P AR(D)f ) about the direct fraction (SWi) due to the impact of Aerosols Organic emitted during biomass burning (BBOA). A statistically significant reduction and increase in biophysical variables was also observed, such as leaf canopy temperature (LCT ) and Vapor Pressure Deficit (V PD), respectively. An average increase of ∼ 3.0 ◦C and 10-15 % reduction in LCT and Tair was found under densely smoky sky conditions (AOD a ≫ 0.10). These results are useful in obtaining new calibration coefficients and new physical parameterizations of processes poorly represented in current numerical systems, such as the photosynthetic responses of semi-deciduous forests to regional carbon cycling in the Amazon. These findings also guide public policies for preserving the Cerrado-Amazon Forest ecotone and other pantropical ecosystems. We have prepared an essay highlighting the weaknesses and unfeasibility of political actions aimed at pricing carbon and ecosystem services, such as the sequestration of CO2. To this end, law 2,187/2009 (National Climate Change Policy) and PL-528A/2021 (Regulation of the Brazilian Emissions Reduction Market) are analyzed. As a result, it indicates the failures of the law above and refutation. It discusses unfeasibility, pointing out feasible solutions for new forms of exploitation, contrary to this mercantile logic that neglects the peculiarities and resilience of Amazonian ecosystems, supported by the idea of exploiting natural resources as a means unique for economic development and progress, thus hiding the current ecological crisis in which we live.