Sacramento—Scientists have
said for years that global warming was “loading the dice” when it comes to
increasing the frequency of severe storms, and a new Environment California report
makes it clear that California is already experiencing extreme downpours much
more frequently. Specifically, the new
report found that storms with heavy rainfall are now 26 percent more frequent in
California
than they were 60 years ago.
“At the rate we’re going,
what was once the storm of the decade will soon seem like just another downpour,”
said Jason Barbose, Global Warming Advocate with Environment California.
Barbose pointed to the rainstorm
that hit southern California in January of 2005
as an illustration of what more extreme rainstorms could mean for California. That rainstorm, which dumped 30 inches of
rain on the Southland, led to millions of dollars of flood and storm-related
damage throughout southern California and
tragic loss of life, including 10 deaths attributed to a landslide into homes
in the small coastal community of La Conchita (Ventura County).
“More frequent downpours,
fueled by global warming, will leave California
even more vulnerable to dangerous flooding in years to come,” said Barbose.
The new Environment California report, When it Rains, It Pours: Global Warming and
the Rising Frequency of Extreme Precipitation in the United States, examines
trends in the frequency of large rain and snow events across the continental United
States from 1948 to 2006. Using data
from 3,000 weather stations and a methodology originally developed by
scientists at the National
Climatic Data
Center and the Illinois
State Water Survey, the report identifies storms with the greatest 24-hour
precipitation totals at each weather station, and analyzes when those storms
occurred.
Nationally, the report shows that
storms with extreme precipitation have increased in frequency by 24 percent
across the continental United
States since 1948. At the state level, 40 states show a
significant trend toward more frequent storms with extreme precipitation, while
only one state (Oregon)
shows a significant decline.
Key findings California and the
Pacific West include:
- Storms with extreme precipitation increased in
frequency by 18 percent in Pacific coast states from 1948 to 2006.
- California experienced a 26 percent increase in extreme
rainstorms during the period studied.
- In addition, the Los Angeles metropolitan area shows a
significant increase in the frequency of large storms with heavy
precipitation, roughly estimated to be a 58 percent increase over the
nearly 60-year period.
These findings are consistent
with the predicted impacts of global warming.
Scientists expect some parts of the United States to receive more
precipitation as a result of global warming, while other parts receive
less. But regardless of the trend in
total precipitation, scientists predict that the rain and snow that does fall
will be more likely to come in big downpours and heavy snowstorms.
Barbose was careful to note
that an increase in the frequency of extreme rainstorms does not mean more
water will be available. Scientists
expect that, as global warming intensifies, longer periods of relative dryness
will mark the periods between extreme rainstorms, increasing the risk of
drought. For example, the Intergovernmental
Panel on Climate Change (IPCC) predicts that, under a scenario of intense
warming, the percent of land enduring severe drought globally could be 30 times
greater by the end of the century than it is today.
“How serious this problem
gets is largely within our control – but only if our country acts boldly to
reduce the pollution that fuels global warming,” said Barbose.
According to the most recent
science, the United States
must reduce its total global warming emissions by at least 15 percent by 2020
and by at least 80 percent by 2050 in order to prevent the worst effects of
global warming.
“Steep reductions in global
warming pollution are challenging but achievable,” noted Barbose, “and we
already have the energy efficiency and renewable energy technologies we need to
get started.”
Tomorrow, the U.S. Senate
Environment & Public Works (EPW) Committee is expected to vote on
amendments to the “Lieberman-Warner Climate Security Act of 2007” (S. 2191), a
global warming bill introduced by Senators Lieberman (I-CT) and Warner
(R-VA). While recognizing the important
efforts of the bill’s supporters on this critical issue, Environment California
said that the legislation must be significantly strengthened to address the
challenge of global warming.
Specifically, the bill’s current pollution reduction targets fall short
of what the science says is necessary to avoid the worst effects of global
warming, and the bill gives away far too many subsidies to dirty and dangerous
energy sources.
“If we are going to solve the
problem of global warming, this bill must be substantially strengthened. Environment California urges Senator Boxer to vote to
strengthen the bill to require science-based pollution reduction targets, and
to limit giveaways to dirty and dangerous energy sources,” concluded Barbose.
