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
Colorado report makes it clear that Colorado and the Mountain West is already
experiencing extreme downpours and heavy snowstorms much more frequently.
Specifically, the new report found that storms with heavy rainfall or snow are
up 30 percent in Colorado and 25 percent across the Mountain
West compared to 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 Keith Hay, Energy
Advocate at Environment Colorado
Hay pointed to the rainstorm that hit Denver in March of 2003 as
an illustration of what more extreme rainstorms could mean for the region. That
storm dumped over 5 inches on the area. “More frequent downpours, fueled by
global warming, will hurt Colorado’s water quality and leave Colorado even more
vulnerable to dangerous flooding in years to come,” said Keith Hay.
The new Environment Colorado 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 for the Mountain West and Colorado
include:
- Storms with extreme precipitation increased in frequency
by 25 percent in Mountain West from 1948 to 2006.
- Colorado experienced a 30 percent increase in
extreme rainstorms during the period studied.
- In
addition, Grand
Junction shows a significant increase in the frequency of
large storms with heavy precipitation, roughly estimated to be a 53 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.
Hay 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 we act boldly to reduce the pollution that fuels global
warming,” said Hay
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 Hay, “and we already have the energy
efficiency and renewable energy technologies we need to get
started.”
Today, 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 Colorado
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.
“In addition to calling for a strengthening of the
“Lieberman-Warner Climate Security Act of 2007”, U.S. Senators Ken Salazar and
Wayne Allard should cosponsor the Global Warming Pollution Reduction Act – the
only legislation in Congress that would reduce pollution fast enough to protect
future generations from the worst effects of global warming,” concluded
Hay.
When-It-Rains-It-Pours---CO.pdf