201 © Springer International Publishing AG, part of Springer Nature 2019 C. A. Nobre et al. (eds.), Climate Change Risks in Brazil, https://doi.org/10.1007/978-3-319-92881-4_8 Chapter 8 Assessing the Possible Impacts of a 4 °C or Higher Warming in Amazonia Gilvan Sampaio, Laura S. Borma, Manoel Cardoso, Lincoln Muniz Alves, Celso von Randow, Daniel Andrés Rodriguez, Carlos A. Nobre, and Felipe Ferreira Alexandre 8.1 Introduction The Amazon region occupies the largest contiguous forest area on the planet and is responsible for numerous environmental services, among which are: habitat of about 10 to 15% of land biodiversity (Hubbell et al., 2008; Lewinshohn and Prado, 2002; Nobre et al., 2016) climate regulation (Li et al., 2015) and freshwater produc- tion, contributing with around 15% - 20% of all freshwater discharged into oceans annually (Barthem et al., 2004; Molinier, Guyot, De Oliveira, & Guimarães, 1996). From the point of view of climate regulation, the Amazon operates on several scales. At the global scale, it is responsible for the storage of about 150–200 Pg of carbon in living biomass and soils (Feldpausch et al., 2012), which could otherwise be released into the atmosphere with strong impacts on the global climate (e.g., Ballantyne, Alden, Miller, Tans, & White, 2012; Le Quéré et al., 2013; Pan et al., 2011; Phillips et al., 2009). On the local and regional scales, Amazon forest exerts control on rainfall and temperature through evapotranspiration (ET), in a process known as ‘moisture recycling’. A number of studies attempted to quantify the water G. Sampaio () Center for Weather Forecasting and Climate Studies/National Institute for Space Research (CPTEC/INPE), São Paulo, Brazil e-mail: gilvan.sampaio@cptec.inpe.br L. S. Borma · M. Cardoso · C. von Randow · F. F. Alexandre Earth System Science Center/National Institute for Space Research (CCST/INPE), São Paulo, Brazil L. M. Alves National Institute for Space Research (INPE), São Paulo, Brazil D. A. Rodriguez Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil C. A. Nobre Institute for Advanced Studies, University of São Paulo, São Paulo, Brazil jose.marengo@cemaden.gov.br