Amazon rainforest could reach ‘tipping point’ by
2050, scientists warn
Authors of study call for action to prevent possible
collapse of region’s ecosystems and climate impacts that would result
PA Media
Wed 14 Feb
2024 16.00 GMT
Swathes of
the Amazon face pressures that could lead to a “tipping point” by 2050,
prompting large-scale collapse of the key forest systems, scientists have
warned.
A study
published in the journal Nature found that by the middle of the century, 10% to
47% of Amazonian forests will be threatened by a combination of impacts
including global warming, changing rainfall, longer dry seasons, deforestation
and fires.
That could
trigger the collapse of forest ecosystems, potentially driving further climate
change, causing irreversible loss of wildlife, affecting rainfall across the
region and South America, and hitting lives, cultures and livelihoods, the
paper said.
The Amazon
rainforest holds more than 10% of Earth’s land-based wildlife, stores an amount
of carbon equivalent to 15 to 20 years of global emissions from human activity,
and has a cooling effect that helps stabilise the climate.
But the
resilience of the region’s forests has been decreasing since the early 2000s,
the study warned.
The
research, by scientists in Brazil and around the world, looked at causes of
water stress in the Amazon that is putting pressure on the forests, using
natural records from across 65 million years, climate models and data such as
satellite images of forest fire spread and deforestation since the 1980s.
The Amazon
is threatened by rising temperatures, an increase in the number of consecutive
dry days, and changes to rainfall patterns that are making some areas much
drier and others wetter, it said.
As much as
38% of the remaining Amazon forest has been degraded by logging, fires under
the canopy, and repeated extreme drought, while road networks are pushing the
damage throughout the core of the ecosystem, the study said.
By 2050,
10% to 47% of the area will be exposed to a combination of threats that may
trigger a shift from natural forest to different landscapes such as savannah
and degraded forests or other areas with low tree cover.
This could
threaten the Amazon‘s role as a carbon store or sink, make local climate change
impacts worse, and affect the 40 million people who live there, including
indigenous people and local communities, the study said.
Potsdam
Institute for Climate Impact Research (PIK) scientist Boris Sakschewski, one of
the authors of the study, said: “The south-eastern Amazon has already shifted
from a carbon sink to a source – meaning that the current amount of human
pressure is too high for the region to maintain its status as a rainforest over
the long term.
“But the
problem doesn’t stop there. Since rainforests enrich the air with a lot of
moisture which forms the basis of precipitation in the west and south of the
continent, losing forest in one place can lead to losing forest in another in a
self-propelling feedback loop or simply ‘tipping’.”
The
researchers suggested safe boundaries for each of the critical drivers behind
the threats – for example, calling for global warming to be limited to 1.5C
above pre-industrial levels in line with international agreements.
They also
said deforestation should be limited to 10% of the original Amazon forest
cover, which requires ending large-scale deforestation and restoring at least
5% of the region, which has already lost as much as 15% of its forests.
Co-author
Niklas Boers, from PIK and professor of Earth system modelling at the Technical
University of Munich, said: “To maintain the Amazon forest within safe
boundaries, local and global efforts must be combined.
“Deforestation
and forest degradation have to end and restoration has to expand. Moreover,
much more needs to be done to stop greenhouse gas emissions worldwide.”
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