Thunderstorms Caused by Climate Change Will Most Likely Increase the Number of Large Windthrow Events in the Amazon

Tropical forests are critical for absorbing CO2 from the atmosphere. They are, however, vulnerable to severe storms, which can result in "windthrow," or the uprooting or breaking of trees.

As these downed trees decompose, they have the potential to transform a forest from a carbon sink to a carbon source.

Climate change likely to uproot more Amazon trees

(Photo : Ivars Utināns/Unsplash)

According to a new study, more extreme thunderstorms caused by climate change will likely result in an increase in the number of large windthrow events in the Amazon rainforest, as per ScienceDaily.

This is one of the few ways researchers have established a link between storm conditions in the atmosphere and forest mortality on land, filling a significant gap in models.

"Building this link between atmospheric dynamics and damage at the surface is very important across the board," said Jeff Chambers, a senior faculty scientist at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the project director of the Next Generation Ecosystem Experiments (NGEE)-Tropics.

"It's not just for the tropics; it's also for high-latitude, low-latitude, and temperate-latitude areas in the United States."

Researchers discovered that by the end of the century, the Amazon will likely see 43% more large blowdown events (of 25,000 square meters or more).

The area of the Amazon that is likely to experience extreme storms with large windthrows will also increase by about 50%.

On January 6, the study was published in the journal Nature Communications.

Researchers compared a map of over 1,000 large windthrows with atmospheric data to discover the link between air and land.

They discovered that a metric known as CAPE, or "convective available potential energy," was an accurate predictor of major blowdowns.

CAPE is a measure of the amount of energy available to move parcels of air vertically, and a high CAPE value frequently results in thunderstorms.

Extreme storms can bring strong vertical winds, heavy rains or hail, and lightning, all of which interact with trees from the canopy to the soil.

"Storms account for more than half of forest mortality in the Amazon," said Yanlei Feng, the paper's first author.

Climate change has a significant impact on Amazon forests, but much of the research focus has been on drought and fire, so we hope our research brings more attention to extreme storms and improves our models to work in a changing environment due to climate change.

While this study focused on a future with high carbon emissions (SSP-585), scientists could use projected CAPE data to investigate windthrow impacts in various emissions scenarios.

The new forest-storm relationship is now being integrated into Earth system models by researchers.

Better models will allow scientists to investigate how forests will respond to a warmer future, and whether they will continue to remove carbon from the atmosphere or become a contributor.

Also Read: Dams Induce Widespread Species Extinction in the Amazon Forest, Research Says

A changing Amazon?

As habitat destruction trends interact with climate change, the Amazon is at risk of becoming entangled in a series of "feedback loops" that could dramatically accelerate the rate of forest loss and degradation, bringing the Amazon Biome to a point of no return, as per the WWF.

This threshold, also known as a tipping point, may occur when Amazonian forests die and are gradually replaced by fire-prone brush and savanna (ecological tipping point), and regional rainfall is inhibited (climatic tipping point).

The Amazon forests' "die back" has been dubbed after the climate and deforestation-driven conversion of forests to savanna-like and semiarid vegetation.

While scientists are still debating this concept, some climate-simulation vegetation models predict that such a die-back could occur by the end of the century.

According to some scientists, this timeframe is too optimistic because these models do not account for land-use change or the synergistic effects of deforestation and regional climate change.

If these factors are considered, we may face a dire scenario in which current trends in livestock, agriculture, logging expansion, fire, and drought destroy or severely damage 55% of the Amazon rainforest by 2030.

Related article: Brazil Records Big Increase in Amazon Forest Fires