The Future Climate of Amazonia Scientific Assessment Report Antonio Donato Nobre ARA Articulación Regional Amazônica The Future Climate of Amazonia Scientific Assessment Report 1st edition Antonio Donato Nobre Sao Jose dos Campos – SP Edition ARA, CCST-INPE e INPA 2014 The Future Climate of Amazonia Scientific Assessment Report Author: Antonio Donato Nobre, PhD* Researcher at CCST** MCTi/INPE Researcher at MCTi/INPA Patronage: Articulación Regional Amazónica (ARA) Institutional Sponsorship: Earth System Science Center (CCST) National Institute of Space Research (INPE) National Institute of Amazonian Research (INPA) Strategic Partnership: Avina and Avina Americas Fundo Vale Fundação Skoll Support: Instituto Socioambiental Flying Rivers Project WWF N669f Nobre, Antonio Donato The future climate of Amazonia: scientific assessment report / Antonio Donato Nobre; translation Ameri- can Journal Experts, Margi Moss –São José dos Campos, SP: ARA: CCST-INPE: INPA, 2014. e-book : il. Translation of: O futuro climático da Amazônia: relatório de avaliação científica. ISBN: 978-85-17-00074-4 1. Climatology. 2. Amazon (Region). 3. Environment. I. Title. CDU: 551.58 Cite the report as: Nobre AD, 2014, The Future Climate of Amazonia, Scientific Assessment Report. Sponsored by CCST-INPE, INPA and ARA. São José dos Campos, Brazil, 42p. Available online at: http://www.ccst.inpe.br/wp-content/uploads/2014/11/ The_Future_Climate_of_Amazonia_Report.pdf This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/. * Antonio Donato Nobre (curriculum Lattes) studies the Earth system through an interdisciplinary approach and works to popularize science. He has been a senior researcher at the National Institute of Amazonian Research (INPA) since 1985 and has worked since 2003 at the National Institute of Space Research (Instituto Nacional de Pesquisas Espaciais). ** The Earth System Science Center (Centro de Ciência do Sistema Terrestre) is a new department at INPE for interdisciplinary research on the Earth as a System. This assessment of the future of the Amazon’s climate 2 It goes on to describe the capabilities of the rainfor- consists of a concise review and synthesis of the scien- est in its virgin state: the Amazon forest -the green- tific literature combined with an analytic interpretation ocean1- and its relationship with the atmosphere -the of the key issues on the subject. gaseous-ocean-, with which it exchanges gases, water and energy, and with the Atlantic -the blue-ocean-, While focusing on the science, the report is couched in the primary source and final repository of the water accessible language and adopts a holistic perspective, that irrigates the continent. Ever since the studies of seeking to put numerous sources and expert analyses Humboldt2, modern science and traditional indige- into a single coherent picture of the Amazon ecosystem. nous knowledge have clarified important mysteries regarding the powers of the great rainforest over The report seeks to trace the climatic potential of the the elements that make up the Earth’s climate. We world’s greatest remaining rainforest, its functions crit- explore five discoveries important to Amazonian ical to human society and its destruction through de- ecohydrology. forestation and fire. It further discusses what needs to Executive summary be done to stop the runaway train that the climate has Unraveling the mysteries of the Amazon become since human occupation in forest areas. The first mystery involves the humidity that the Since the subject is vast, it needs to be examined in rainforest maintains in moving air, and which brings chronological sequence. rain to mainland areas that are located far from the oceans. This occurs due to the innate ability of trees 1 The text begins with an overview of the key fac- to transfer large volumes of water from the soil to tor in geological history: the network of Amazonian the atmosphere through transpiration. biodiversity, which developed its current functional capacities over tens of millions of years. Life process- The second mystery concerns the formation of es that operate in rainforests have developed an abundant rainfall in clean air. Amazonian trees emit almost incomprehensible complexity, with an as- volatile substances that act as precursors of con- tronomical number of organisms working together densation nuclei for water vapor. The efficiency of like gears linked into a phenomenal environmental these particles in cloud nucleation results in benign regulation machine. and bountiful rainfall. 1 The term green-ocean describes the ocean-like characteristics of this continental expanse covered by dense forests. The importance of this novel concept lies in its suggestion of a forest surface, stretched out below the atmosphere, where vastness, wetness and exposure to wind closely resemble characteristics akin to the actual oceans. 2 Alexander von Humboldt, influential German scientist-naturalist, who explored the Americas at the turn of the 18th century to the 19th century, considered the father of sciences such as geography, physics, meteo- rology and ecology. The Future Climate of Amazonia • Executive summary 4 The third mystery is related to the rainforest’s ca- by lateral transport from over the ocean deprives affecting climate that emerges from this analysis is pacity to survive climatic cataclysms and its formi- the storms of their food (water vapor) in the oceanic the severe cumulative extent of deforestation, an dable powers to sustain a beneficial hydrological regions adjacent to big forests. area measured up to 2013 in the Brazilian Amazon at cycle, even under unfavorable external conditions. nearly 763,000 km2 (the combined area of two Ger- According to the biotic pump theory3, profuse tree All these effects combine together to make the ma- manys or two Japans). This surface measurement, transpiration, combined with very strong conden- jestic Amazon rainforest the very best and most furthermore, needs to be added to the impacted area sation in the formation of clouds and rainfall – a valued partner for all human activities that require of the little studied and seldom-mentioned extent of condensation far greater than that which occurs measured amounts of rain, a mild climate, and pro- forest degradation (estimated to exceed 1.2 million over adjacent oceans – leads to a reduction in at- tection against extreme events. km2) that is likely to be a factor influencing climate. mospheric pressure over the forest which, in turn, draws moist air over the oceans inland, maintaining 3 The report continues with a description of the ef- 4 The report continues by relating the green-ocean rainfall levels under most circumstances. fects of deforestation and fire on climate: the dev- rainforest and deforestation in the context of lon- astation of the Amazon rainforest generates a dra- ger periods of time: vegetation-climate equilibrium The fourth mystery explains why the southern por- matically inhospitable climate. Over 20 years ago, teetering on the brink of the abyss. Climate models tion of South America on the eastern side of the An- climate models predicted various harmful effects of that are interactively linked to vegetation models des is not a desert, as is the case with other areas deforestation on the climate, and these have been can be used to explore which surface-areas of dif- at the same latitudes both west of the Andes and confirmed by observations. Among these effects ferent types of vegetation and what climate condi- on other continents. The Amazon rainforest not only are drastic, widespread decreases in forest transpi- tions are capable of generating stable climate-veg- keeps the air moist for its own purposes, but also ex- ration, changes in the dynamics of clouds and rain, etation equilibria. ports water vapor via aerial rivers, which carry the and the extended duration of the dry season. Oth- water that will produce the abundant rainfall that ir- er side-effects that had not been predicted, such For Amazonia, current models project the possibil- rigates distant regions during the summer months. as the damaging effects of smoke and soot on rain ity of two equilibrium points: one that favors the processes, have also been observed, even over un- forest (humid, the current and historical state of the The fifth mystery provides the reason why the Am- disturbed green-ocean rainforest areas. Amazon basin) and another that favors the savanna azon and the oceans nearby do not allow certain (drier, the current conditions in the cerrado4 -- a po- atmospheric phenomena, such as hurricanes and The damage inflicted on the Amazon climate by de- tentially bleak future for the Amazon basin). extreme weather events, to propagate. Evenly dis- forestation, fire, smoke and soot is already glaringly tributed condensation over the wrinkled forest can- apparent in both scientific field measurements and A point of concern behind these modeling exercises opy precludes the concentration of wind power in in leading climate-modelling scenarios. Analysis is the clear indication that a reduction of approxi- damaging vortices like hurricanes or tornadoes on based on updated climate models and on new phys- mately 40% of the rainforest may trigger a large- land, while the depletion of atmospheric moisture ical theory predicts a worse future. The major factor scale transition to a savanna equilibrium, in time 3 (Makarieva & Gorshkov, 2007) Biotic pump of atmospheric moisture as driver of the hydrological cycle on land. 4 N. of T. The “cerrado” is a type of savanna found in the Brazilian territory The Future Climate of Amazonia • Executive summary 5 eliminating even forests that have not been felled. Second, it is necessary to stop the bleeding and de- Current clear cutting deforestation in the Brazilian struction of the forest, i.e., to halt deforestation, for- Amazon corresponds to approximately 20% of the est degradation and fire immediately using any and original forest cover, and forest degradation is es- all possible and ethical means.