Indian monsoons worsen as climate changes -study
UNITED STATES: India's monsoon rains have intensified over the
last half-century as average temperatures have risen, and more severe
weather could be in store if global warming continues, scientists
reported on Thursday.
Heavy rains come more frequently and are more severe now than they
were in 1951, the researchers wrote in the journal Science. At the same
time, moderate rains the kind that are more easily absorbed decreased,
leaving the mean rainfall record about the same as it was five decades
ago.
"The extreme events are so damaging because they pour in a large
amount of rainfall over a small area in a very short time, leading to
flash floods and landslides," B.N. Goswami of the Indian Institute of
Tropical Meteorology wrote in answer to e-mailed questions.
"On the other hand weak and moderate events do not cause such damage
and help recharge the ground water," Goswami wrote.
If this trend continues, the number of extreme rain events could
reach 100 per year, more than double the 45 or so such events common in
the 1950s in central India, he wrote.
The researchers defined an extreme rain event as one where at least
3.9 inches (100 mm) of rain fell.
The average temperature increase in India between 1950 and 2000 is
about .9 degree Fahrenheit (0.5 degree Celsius), Goswami said. That
corresponds with the global rise in temperature.
Most scientists believe global warming is caused by the release of
greenhouse gases, including carbon dioxide emitted by motor vehicles and
some factories. These gases trap heat near Earth's surface like the
glass walls of a greenhouse.
WASHINGTON, Friday, Reuters |