According to the report on the Amazonian climate future Futuro Climatico da Amazonia, produced by Antonio Donato Nobre of the Brazilian National Institute for Space Research (Inpe) and requested by Ara (Amazonian Regional Articulation), the Amazonian forest fulfils the role of regulating the climate, in particular through the trees’ capacity to transfer enormous quantities of water from the ground to the atmosphere, through transpiration. A good 20 billion tonnes of water each day are used in transpiration, the equivalent of 20 thousand billion litres: as a comparison the Amazon River feeds, each day, into the ocean about 17 billion tonnes. The trees work, in fact, as «woody geysers», transferring immense volumes of water into the atmosphere.
This extraordinary cycle between biosphere and atmosphere also allows for important processes of condensation, forming clouds and rain through the exchange and movement of warm, moist air from the ocean to the mainland, resulting in extremely important means of precipitation for the whole forest, a dynamically stable climate and a real protection from extreme meteorological events. Deforestation puts all this system at risk, drastically reducing the mechanisms of evapotranspiration, with a change in the formation of clouds, the dynamics of precipitation and prolonging of dry seasons with consequent drying up of various Amazonian areas.
The report calculates that from the non tribal human occupation of Amazonia, at least 42 billion trees, about 2000 trees a minute, have been destroyed continuously for at least 40 years. The Amazonian forest is essential in the delicate dynamic equilibrium of the climate system. This aspect is, in fact, dealt with in the Fifth Report on Climate Changes carried out by the IPCC (Intergovernmental Panel on Climate Change).