North County Times, CA
10-10-07
CSD scientist: 20 years wasted on climate debate
By: DAVE DOWNEY - Staff Writer
LA JOLLA -- For UC San Diego scientist and historian Naomi Oreskes, global
warming is old news.
As early as 1979, Oreskes said, there was broad consensus among scientists
that the growing concentration of greenhouse gases in the atmosphere from
fossil fuel burning was heating up the planet, Oreskes said.
The nation's leaders could have -- and should have -- started doing something
about it then, she said in a lecture Monday night sponsored by UC San Diego's
Scripps Institution of Oceanography.
"In my view, we have wasted 20 years," Oreskes said.
The view that man-made greenhouse gases such as carbon dioxide are to blame
for climate change is widely held by the scientific community. But some scientists
remain uncertain that the planet is on a track toward accelerated warming and
have doubts about the role such gases are likely to play.
Bill Sheehan of San Diego, a product manager for a cell phone company, said
Oreskes made a compelling argument that climate change is indeed occurring
and that scientists have known about it a long time.
"OK, yes there's global warming. OK, man caused it. But isn't it too late to do
anything about it?" Sheehan asked Oreskes after the lecture, as attendees
crowded around to talk to her.
Her answer? No.
Oreskes said there is still time to slow the buildup of carbon dioxide and other
gases and slow the warming before it triggers widespread melting of continental
ice sheets. Melting on a large scale could flood low-lying coastal regions, reduce
California's crucial mountain snowpack and cause widespread famine in Third
World countries, scientists say.
Greenhouse gases act like a blanket over the planet, capturing a portion of the
sun's heat that otherwise would escape into space.
"If there were no greenhouse gases in the atmosphere, we would be much, much
colder," Oreskes said. "We would be like the moon or Mars."
The problem is, the greenhouse blanket is thickening. Scripps scientists say
carbon dioxide levels have increased from 280 parts per million at the dawn of
the industrial age to about 380 parts per million, and are on track to soar higher.
Titled "The American Denial of Global Warming," the hourlong talk was held at
the Birch Aquarium and attended by 330 people. Oreskes is the author of a
widely cited 2004 essay, "The Scientific Consensus on Climate Change."
Not everyone in the scientific community agrees with Oreskes' assessment.
Bill Gray, a Colorado State University climate scientist who specializes in
hurricanes, said in a telephone interview Tuesday there was no consensus in
1979. And he said support for the theory that human activities are the only or
primary cause of recently observed warming is hardly unanimous today.
"The trouble is, this has become a religion with people," Gray said, referring to
those such as Oreskes who say greenhouse gases are fueling a wholesale
change in the climate. "And you just can't argue with religion. Facts don't matter."
Gray said he personally believes the buildup of greenhouse gases will fuel a rise
in temperature, but not nearly to the degree that many predict.
He said the factors that contribute to the planet's temperature are complex, and it
is his opinion that ocean currents exert much more influence than man-made
carbon dioxide. Gray maintains the Earth, spurred on by changing currents,
actually will begin to cool several years from now.
Amy Kaleita, a professor of agricultural and biosystems engineering at
Iowa State University who last month wrote a paper on environmental
"alarmism" for the Pacific Research Institute, a conservative San Francisco think
tank that gets its funding from large corporations and foundations. said the public
is confused about the matter because the term consensus is misused.
"We agree generally that there is a link between elevated atmospheric levels of
greenhouse gases and rising global temperatures," Kaleita said.
But, she said, opinions vary as to how much of an effect elevated carbon levels
will have, how much temperatures will rise and precisely what environmental
problems will result.
Oreskes, the Scripps scientist, said that on the contrary the public is confused
because over the last two decades industry advocates have sought
systematically to sow seeds of doubt about global warming.
"They have confused the public and they have delayed political action on one of
the most critical issues of our time," she said.
Oreskes said the truth is the scientific community began to suspect greenhouse
gases would boost the planet's temperature as early as the 1930s, when the
theory was advanced by physicist E.O. Hulburt.
After a hiatus from the issue during World War II, research continued in the
1950s and 1960s. And in 1979, Oreskes said, the National Academy of Sciences
concluded that a "plethora of studies" had shown the burning of fossil fuels would
significantly change the climate.
Not only that, she said, at that time scientists predicted warming would occur
faster near the poles, something that already has occurred. Oreskes said
weather records show that the average global temperature rose 0.53 degrees
Centigrade (1 degree Fahrenheit) while Alaska's rose 2.1 degrees Centigrade (4
degrees Fahrenheit) from just after the middle of last century to this decade.
"So, if someone tells you that no one could have predicted this, not only could
they have, but they did," she said.
-- Contact staff writer Dave Downey at (760) 745-6611, Ext. 2623, or
ddowney@nctimes.com.