ENN Twitter
<!–
–>
In research meant to highlight how the destruction of
the Amazon rainforest could affect climate elsewhere, Princeton University-led
researchers report that the total deforestation of the Amazon may significantly
reduce rain and snowfall in the western United States, resulting in water and
food shortages, and a greater risk of forest fires.
ADVERTISEMENT
The
researchers report that an Amazon stripped bare could mean 20 percent less rain
for the coastal Northwest and a 50 percent reduction in the Sierra Nevada
snowpack, a crucial source of water for cities and farms in California.
Previous research has shown that deforestation will likely produce dry air over
the Amazon. Using high-resolution climate simulations, the researchers are the
first to find that the atmosphere’s normal weather-moving mechanics would
create a ripple effect that would move that dry air directly over the western
United States from December to February.
Specifically, a denuded Amazon would develop a weather
cycle consisting of abnormally dry air in the sun-scorched northern Amazon
around the equator weighted by wetter air in the cooler south. Research has
speculated that this pattern would be similar to the warm-water climate pattern
El Niño, which during the winter months brings heavy precipitation to southern
California and the Sierra Nevada region while drying out the Pacific Northwest.
The Princeton-led researchers found that the Amazon pattern
would be subject to the same meandering high-altitude winds known as Rossby
waves that distribute the El Niño system worldwide from its source over the
Pacific Ocean. Rossby waves are instrumental forces in Earth’s weather that
move east or west across the planet, often capturing the weather of one region
— such as chill Arctic air — and transporting it to another. Because the Amazon
pattern forms several thousand miles to the southeast from El Niño, the researchers
report, the Rossby waves that put the rainy side of El Niño over southern
California would instead subject that region to the dry end of the Amazon
pattern. The pattern’s rainy portion would be over the Pacific Ocean south of
Mexico.
First author David Medvigy,
an assistant professor of geosciences
at Princeton, explained that the findings stand as one possible outcome of
Amazon deforestation in regions outside of South America — consequences that
scientists are working to understand. The rainforest influences various aspects
of the surrounding climate, including cloud coverage, heat absorption and
rainfall.
Read more at Princeton
University.
Brazilian
Rainforest image and Death
Valley image via Shutterstock, combined by Robin Blackstone.
Terms of Use | Privacy Policy
2013©. Copyright Environmental News Network