Methane emissions from 2010 to 2022 in Amazon

CH₄ is the second most important Greenhouse gas, behind CO₂, but it has a greater warming potential, around 86 times per unit mass, than CO₂ on a 20-year time scale. Anthropogenic sources such as fossil fuels, agriculture and waste are responsible for a large part of global CH₄ emissions. From 1999 to 2006, the atmospheric CH₄ concentrations showed stability, but since 2007 it has been increasing rapidly and the causes of this increase are still unknown. With aquatic ecosystems extending over approximately 20% of its territory, the Amazon is responsible for a large part of CH₄ emissions from tropical regions. Over the last 40/50 years, anthropogenic activities in the Amazon have caused a considerable impact, resulting in a 17% loss of primary forest cover. In this context, it is important to understand the Amazon participation in the variations of the global atmospheric CH₄ growth rates. To elucidate the Amazon's participation in the global atmospheric methane balance, we used data involving a long time series of more than a decade (from 2010 to 2022) of vertical CH₄ concentrations profiles, obtained at four locations that represent the southeast (ALF), northeast (SAN), northwest (TAB/TEF/CZS) and southwest sectors of the Amazon (RBA). The preliminary results of this study shows that the concentration for the Amazon have the same growth rates as the global atmospheric CH₄. The northeast region has higher CH₄ concentrations than the others. The monthly fluxes calculated for the four regions studied show seasonal variation, while a preliminary analysis of the annual fluxes shows a large variability in Amazon CH₄ balance. The possible causes of these annual variability could be linked with climatic variations, but the cause still being discussed.