Study predicts a much hotter, drier California
- Fw: [fuelcell-energy]
---------- Forwarded Message ----------
Study predicts a much hotter, drier California
- Jane Kay, Chronicle Environment Writer
Tuesday, August 1, 2006
California will become significantly hotter and drier by the end of
the century, causing severe air pollution, a drop in the water
supply, melting of 90 percent of the Sierra snowpack and up to six
times more heat-related deaths in major urban centers, according to a
sweeping study compiled with help from respected scientists from
around the country.
The weather -- up to 10.5 degrees warmer by 2100 -- would make last
month's heat wave look average. If industrial and vehicle emissions
continue unabated, there could be up to 100 more days a year when
temperatures hit 90 degrees or above in Los Angeles and 95 degrees or
above in Sacramento. Both cities have about 20 days of such extreme
The good news: If emissions of carbon dioxide and other greenhouse
gases are significantly curtailed, according to the report released
Tuesday, the number of extremely hot days might only increase by half
The report, released by the California Environmental Protection
Agency, comes from the California Climate Change Center, established
three years ago by the California Energy Commission. Scripps
Institution of Oceanography and UC Berkeley are responsible for the
core research and about 75 scientists from universities, government
agencies and nonprofit groups contributed to the report, which has
been billed as a layperson's guide to technical documents prepared in
support of initiatives to address global warming by Gov.
Schwarzenegger and legislators.
"What we wanted to do with the document is summarize the scientific
reports, so regular citizens can understand the grave concerns that
we believe are facing California,'' said Claudia Chandler, assistant
executive director of the California Energy Commission.
Climate experts have faith in the reliability of global climate
models and their ability to forecast what will happen to the planet
as the heat-trapping greenhouse gases continue to build in the
atmosphere. However, some scientists have been reluctant to say how
global warming may affect specific regions, including areas the size
of California. That's because there's debate over whether models are
good enough to zoom in on possible local effects of planetary climate
But Chandler said the state was depending on the core of scientists
who prepared the report to use the best models available to help the
state prepare for possible problems looming in the not too distant
future. "We probably won't know until 10 years from now. But that
will be too late. We cannot turn our backs on trying to address this
very serious situation.''
Highlights of the report include:
-- Hotter weather would increase the risk of death from dehydration,
heat stroke, heart attacks, stroke and respiratory distress. Under
the most extreme scenario, heat-related deaths could increase four or
-- The snowpack, the state's top source of fresh drinking water,
could nearly disappear. That would pose a challenge to water agencies
that now rely on slowly melting snow to replenish reservoirs.
-- Power demand could up as much as 20 percent, but hydropower
supplies would drop.
-- Heat stresses dairy cows, which could produce up to 20 percent
less milk. Fruit and nut trees could produce smaller, inferior
quality crops. Wine grape quality could be severely impacted in all
but the coolest growing regions.
-- Sea levels would rise, possibly inundating the Sacramento-San
Joaquin Delta, a source of two-thirds of the state's drinking water.
"We looked at agriculture, one of the state's most important sectors,
and the increased potential of wildfires,'' said Chandler.
"We looked at public health from the standpoint of deteriorating air
quality, and the reduced water from the Sierra Nevada snowpack. We
looked at what rising sea levels would mean to the delta's water
pumps and levees and to the coastal cities of Los Angeles, San
Francisco, Oakland and San Diego.''
The study authors based their assessments on what would happen in
California under three different emissions scenarios. The amount of
emissions would determine the amount of temperature rise over the
century as greenhouse gases trapped excess heat that would otherwise
radiate into space. These scenarios -- which contain varying
assumptions on economic and population growth, use of new efficient
technologies and shifts away from the use of fossil fuels -- have
been adopted by the United Nations Intergovernmental Panel on Climate
Change, a collaboration of 2,000 scientists from 100 countries.
With continued higher emissions, temperature rises are projected
between 8 and 10.5-degrees compared to medium emissions with
temperature rises between 5.5 and 8-degrees Fahrenheit. With lower
emissions, the temperature is projected to rise between 3 and 5.5
Those varying scenarios could significantly impact how global warming
affects California, the report said. For example, if temperatures
rise as much as 5.5 degrees, there will be 75 to 85 percent more days
with weather conducive to production of unhealthful smog in Los
Angeles and the San Joaquin Valley than now, it said. The days could
be cut if emissions stayed at the lower scenario.
Sea levels have already risen about seven inches along the California
coast in the past century. If greenhouse gases continue and
temperatures rise into the upper range, the ocean is expected to rise
22 to 35 inches by the end of the century.
The mix of increasingly severe winter storms and high tides are
expected to cause more frequent and severe flooding, erosion and
damage to coastal structures, the report said.
The report concludes that California policy alone cannot
significantly affect the warming planet.
"California alone cannot stabilize the planet. However, the state's
actions can drive global progress," the report concludes. If other
states and nation's follow California's example of limiting emissions
of greenhouse gases "we would be on track to keep temperatures from
rising ... and thus avoid the most severe consequences of global
E-mail Jane Kay at jkay@....
SCENARIOS OF CLIMATE CHANGE IN CALIFORNIA: AN OVERVIEW
A Report From:
California Climate Change Center
Dan Cayan, Scripps Institution of
Oceanography, University of California, San
Amy Lynd Luers, Union of Concerned
Michael Hanemann, University of California
Guido Franco, California Energy Commission
Bart Croes, California Air Resources Board
Yahoo! Groups Links