365 Days of Climate Awareness 339 – AR6 Vol. 2, Chap. 12: Central and South America

Not only are Central and South America exposed climatically to risks from global warming, but also societally due to unstable governments and extreme inequality, which make social upheaval a much larger and more ongoing threat. The physical narrowness of Central America—at maximum roughly 400 km/250 mi across, and at its narrowest 48 km/30 mi across—gives residents very little ability to avoid impacts of climate change, like droughts and increased storm activity. Meanwhile deforestation is threatening to destabilize the entire region’s climate, and along the west coast, the narrow strip of habitable land is subject to constant climatic disruption.

All images from the IPCC 6th Assessment Report, Vol. 2, Chap. 12. Central and South America, observed and projected hazards: key lower left for specific threat, color code lower right for increase, no change, or decrease.

The Amazon rain forest is under threat from deforestation and increasingly vulnerable to drought. The monsoonal seasons of northern South America are the product of evapotranspiration: the uptake of water and its later release as vapor by blooming plants. This entire climate system will fail, and the region will become arid like eastern Brazil, with enough tree removal. The effects will be disastrous not only for South and Central America, but will affect atmospheric dynamics throughout the Americas and beyond.

South America, main socioeconomic indicators.

Warming has influenced habitats and natural systems in the surrounding oceans and on the coasts as well as throughout the interior. Snowpacks and glaciers in the Andes are disappearing, by as much as 50% since the 80’s, reducing water access for millions. Coral reefs and their associated marine communities are being thinned out as repeated marine heat waves, overfishing, and increasing ocean acidity damage them more and more. Plankton communities—primary producers and consumers—are declining in number or moving poleward, disrupting food webs all along the coast.

Central America, predicted 21st century change in water availability. Left: present level of climate change; center: low emissions scenario; right: high emissions scenario.

Throughout the Andes, particularly on the windward western side, changing weather patterns are disrupting cities, towns and settlements. La Niña events lead to drought along the west coast of South America, causing water insecurity, especially as snowpacks and glaciers vanish. El Niño events lead to excess rainfall, causing floods and mudslides. Rising temperatures and tendency to drought along the coast and eastward have also increased the likelihood of wildfires, which have increased in recent years, and have reduced agricultural productivity, especially in the central and north part of South America.

Tomorrow: Europe.

Be brave, be steadfast, and be well.

IPCC 6th Assessment Report, Vol. 2 Chap. 12