WASHINGTON Climate-warming carbon dioxide
spewed by coal-fired power plants and fossil-fueled vehicles
has been causing hundreds of premature U.S. deaths each year
over the several decades, a new study reported.
The deaths were due to lung and heart ailments linked to
ozone and polluting particles in the air, which are spurred by
carbon dioxide that comes from human activities, according to
the study's author, Mark Jacobson of Stanford University.
As the planet warms due to carbon dioxide emissions, the
annual death rate is forecast to climb, with premature deaths
in the United States from human-generated carbon dioxide
expected to hit 1,000 a year when the global temperature has
risen by 1.8 degrees F (1 degree C).
When the planet gets that hot, which could happen this
century, the world annual death rate is estimated to rise to
21,600, Jacobson said on Friday in a telephone interview.
Earth has warmed about 1.4 degrees F (0.8 degrees C) in the
last 150 years, with most of that gain in the last three
decades. Jacobson said about 700 to 800 U.S. annual deaths in
the most recent years can be attributed to human-caused carbon
Greenhouse gas pollution has spurred the global warming
that is result in a damaging rise in the sea level, droughts
and possibly more severe storms this century. This is the first
time a scientist has specifically linked one human-generated
greenhouse gas to human mortality.
Carbon dioxide is one of several greenhouse gases blamed
for climate change, but it is the one humans have the most
ability to control through regulation of activities that burn
fossil fuels like coal and oil. It is also emitted by natural
IMPACT ON CALIFORNIA
Using a complex computer model and data on carbon emissions
from the U.S. Environmental Protection Agency, Jacobson found
the impact was worse in places that are populous and polluted.
"Of the additional ... deaths per year due to ozone and
particles ... about 30 percent of those occurred in California,
which has 12 percent of the (U.S.) population," he said, noting
that California has six of the 10 most polluted U.S. cities.
"So it was pretty clear ... that climate change was
affecting Californians' health disproportionately to its
population," Jacobson said.
What happens in California is important, since this
populous state has long been a testing ground for U.S.
Jacobson's study, to be published in Geophysical Research
Letters, was released soon after the U.S. Environmental
Protection Agency rejected a bid by California and 15 other
states to let them set higher standards for carbon emissions
from cars, trucks and SUVs than the federal government does.
Jacobson's research was not available before the EPA's
decision on December 19, but the EPA's rejection made points
that Jacobson said are addressed by his study.
In turning down the states' request, EPA argued that
California did not have a special circumstance warranting this
change, that there were no studies isolating carbon dioxide's
effects and none looking at health impacts.
"It's actually occurring right now, it's been occurring for
the past 20 to 30 years," Jacobson said of the deaths related
directly to human-generated carbon dioxide emissions.
He noted, however, that the deaths due to carbon dioxide
are only a small fraction of annual premature deaths caused by
air pollution overall: an estimated 50,000 to 100,000 in the
United States and between 1.5 million to 2 million worldwide.