A third of the Amazon rainforest degraded by human activity – rts.ch

More than a third of the Amazon rainforest may have been degraded by human activity and drought, according to a study released Thursday in the journal Science. Calls for legislation to protect this vital ecosystem in danger have been launched.

The damage inflicted on the Amazon rainforest, which spans nine countries, is significantly greater than previously observed, said the research team, including members from Brazil’s Estadual de Campinas University.

During their studyresearchers have analyzed the consequences of fires, logging, drought and changes to habitats at the edge of the forest, what they call edge effects.

Excluding drought, these phenomena have degraded at least 5.5% of the rest of the forests that make up the Amazon ecosystem, or 364,748 square kilometers, between 2001 and 2018, according to the study.

>> An overview of the degradation processes of tropical forests in the Amazon (read caption):

Underlying drivers (a few of which are shown in gray at the bottom) stimulate disturbances – timber extraction, fire, edge effects and extreme drought – that cause forest degradation. A satellite illustrates attempts to estimate the spatial extent of degradation and associated carbon losses. Impacts (in red) are either local: causing biodiversity loss or affecting the livelihoods of forest dwellers; or distant: for example, smoke affecting the health of city dwellers or causing Andean glaciers to melt due to the deposition of black carbon. [Alex Argozino/Studio Argozino – Science]

Extreme drought more frequent

When the effects of drought are included, the deteriorated area then represents 2.5 million square kilometers, or 38% of the rest of the forests that make up the Amazon ecosystem. (read box).

>> Amazon deforestation is accelerating due to a combination of anthropogenic factors, including drier climatic conditions and policies favoring industrialized agriculture (read caption):

Top left: Map of the Amazon showing the location of wildfires, from 1985 to 2021. Right: Recently burned primary forest near Rurópolis, Pará state, Brazil, September 17, 2020. Bottom left: The rate of deforestation in the Brazilian Amazon is rapidly increasing under the environmental policies of the Bolsonaro administration. After millions of years of serving as a huge global carbon reservoir, the Amazon rainforest is becoming a net carbon source for the atmosphere. [Marizilda Cruppe/Amazonia Real – ESRI/Garmin-GEBCO/NOAA NGDC/Science]

“Extreme drought has become increasingly common in the Amazon due to changing land use patterns and human-induced climate change affecting tree mortality, the number of fires and emissions. of carbon in the atmosphere,” the scientists said.

“Forest fires have intensified during the drought years,” they added, warning of the dangers of “large fires” in the future.

>> Lire: Areas burned in Brazil almost doubled in November

Scientists at Lafayette University in the US state of Louisiana and other institutions are calling for action, in a study on the consequences of human activity on the Amazon ecosystem, also published in the journal Science.

“Changes are happening far too fast for Amazon species, people and ecosystems to adapt,” they argued. (read box). “The laws to avoid the worst consequences are known and must be enacted immediately.”

“To lose the Amazon is to lose the biosphere and not to act is at our peril,” the scientists concluded.

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