EGU2020-11182
https://doi.org/10.5194/egusphere-egu2020-11182
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Amazon Carbon Balance affected by human activities and Climate change

Luciana Vanni Gatti1, Luana Basso1, Lucas Domingues1, Henrique Cassol2, Luciano Marani1, John Miller3, Manuel Gloor4, Luiz Aragao2, Egidio Arai2, Graciela Tejada1, Liana Anderson5, Celso Von Randow1, Wouter Peters6, Alber Ipia Sanchez7, Caio Correia1, Stephane Crispim1, and Raiane Neves1
Luciana Vanni Gatti et al.
  • 1INPE National Institute for Space Research, CCST, São Jose dos Campos, Brazil (lvgatti@gmail.com)
  • 2INPE National Institute for Space Research, Remote Sensing Division, Sao Jose dos Campos, Brazil
  • 3NOAA, ESRL/GMD, Boulder, CO, United States
  • 4University of Leeds, School of Geography, Leeds, United Kingdom
  • 5National Center for Monitoring and Early Warning of Natural Disasters – Cemaden, São José dos Campos, Brazil
  • 6Wageningen University, Wageningen, Netherlands
  • 7INPE National Institute for Space Research, Sao Jose dos Campos, Brazil

Amazon is the major tropical land region, with critical processes, such as the carbon cycle, not yet fully understood. Only very few long-term greenhouse gas measurements regionally represented is available in the tropics. The Amazon accounts for 50% of Earth’s tropical rainforests hosting the largest carbon pool in vegetation and soils (~200 PgC). The net carbon exchange between tropical land and the atmosphere is critically important because the stability of carbon in forests and soils can be disrupted in short time-scales. The main processes releasing C to the atmosphere are deforestation, degradation, fires and changes in growing conditions due to increased temperatures and droughts. Such changes may thus cause feedbacks on global climate.

In the last 40 years, Amazon mean temperature increased by 1.1ºC. The length and intensity of the dry season is also increasing, causing a strong stress each year higher to the forest.

We observed a reduction of 17% in precipitation during dry season and the transition dry to wet season during this same period. This reduction in precipitation and the increase in temperature during the dry season exacerbate vegetation water stress, with consequences for carbon balance.

To understand the consequences of human-driven and climate changes on the C budget of Amazonia, we put in place the first program with regional representativeness, from 2010 onwards, aiming to quantify greenhouse gases based on extensive collection of vertical profiles of CO2 and CO. Regular vertical profiles from the ground up to 4.5 km height were performed at four sites along the main air-stream over the Amazon. Along this period from 2010 to 2018, we performed 669 vertical profiles, over four strategic regions that represent fluxes over the entire Amazon region.

The observed variability of carbon fluxes during these 9 years is correlated with climate variability (Temperature, precipitation, GRACE, EVI) and human-driven changes (Biomass Burning). The correlations were performed inside each influenced area for each studied site and show how high temperature and water stress during dry season are affecting the Amazon Carbon Balance. At Southeast of Amazon these extreme conditions are dominating the annual balance. Fire emission is the main source of carbon to the atmosphere, which is not compensate by the C removal from old-growth Amazon forest. The west Amazon almost compensate the east carbon source. During wet/normal years Amazon Carbon Balance is around neutral, but during dry years the uptake capacity is very compromised.

How to cite: Gatti, L. V., Basso, L., Domingues, L., Cassol, H., Marani, L., Miller, J., Gloor, M., Aragao, L., Arai, E., Tejada, G., Anderson, L., Von Randow, C., Peters, W., Ipia Sanchez, A., Correia, C., Crispim, S., and Neves, R.: Amazon Carbon Balance affected by human activities and Climate change, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11182, https://doi.org/10.5194/egusphere-egu2020-11182, 2020