[Vision2020] Climate Panel Cites Near Certainty on Warming

Art Deco art.deco.studios at gmail.com
Tue Aug 20 06:28:33 PDT 2013

  [image: The New York Times] <http://www.nytimes.com/>

August 19, 2013
Climate Panel Cites Near Certainty on Warming By JUSTIN

An international panel of scientists has found with near certainty that
human activity is the cause of most of the temperature increases of recent
decades, and warns that sea levels could conceivably rise by more than
three feet by the end of the century if emissions continue at a runaway

The scientists, whose findings are reported in a draft summary of the next
big United Nations climate report, largely dismiss a recent slowdown in the
pace of warming, which is often cited by climate change doubters,
attributing it most likely to short-term factors.

The report emphasizes that the basic facts about future climate change are
more established than ever, justifying the rise in global concern. It also
reiterates that the consequences of escalating emissions are likely to be

“It is extremely likely that human influence on climate caused more than
half of the observed increase in global average surface temperature from
1951 to 2010,” the draft report says. “There is high confidence that this
has warmed the ocean, melted snow and ice, raised global mean sea level and
changed some climate extremes in the second half of the 20th century.”

The draft comes from the Intergovernmental Panel on Climate
a body of several hundred scientists that won the Nobel Peace Prize in
2007, along with Al Gore. Its summaries, published every five or six years,
are considered the definitive assessment of the risks of climate change,
and they influence the actions of governments around the world. Hundreds of
billions of dollars are being spent on efforts to reduce greenhouse
emissions, for instance, largely on the basis of the group’s findings.

The coming report will be the fifth major assessment from the group,
created in 1988. Each report has found greater certainty that the planet is
warming and greater likelihood that humans are the primary cause.

The 2007 report found “unequivocal” evidence of warming, but hedged a
little on responsibility, saying the chances were at least 90 percent that
human activities were the cause. The language in the new draft is stronger,
saying the odds are at least 95 percent that humans are the principal

On sea level, which is one of the biggest single worries about climate
change, the new report goes well beyond the assessment published in 2007,
which largely sidestepped the question of how much the ocean could rise
this century.

The new report also reiterates a core difficulty that has plagued climate
science for decades: While averages for such measures as temperature can be
predicted with some confidence on a global scale, the coming changes still
cannot be forecast reliably on a local scale. That leaves governments and
businesses fumbling in the dark as they try to plan ahead.

On another closely watched issue, the scientists retreated slightly from
their 2007 position.

Regarding the question of how much the planet could warm if carbon dioxide
levels in the atmosphere doubled, the previous report largely ruled out any
number below 3.6 degrees Fahrenheit. The new draft says the rise could be
as low as 2.7 degrees, essentially restoring a scientific consensus that
prevailed from 1979 to 2007.

But the draft says only that the low number is possible, not that it is
likely. Many climate scientists see only a remote chance that the warming
will be that low, with the published evidence suggesting that an increase
above 5 degrees Fahrenheit is more likely if carbon dioxide doubles.

The level of carbon dioxide, the main greenhouse gas, is up 41 percent
since the Industrial Revolution, and if present trends continue it could
double in a matter of decades.

Warming the entire planet by 5 degrees Fahrenheit would add a stupendous
amount of energy to the climate system. Scientists say the increase would
be greater over land and might exceed 10 degrees at the poles.

They add that such an increase would lead to widespread melting of land
ice, extreme heat waves, difficulty growing food and massive changes in
plant and animal life, probably including a wave of extinctions.

The new document is not final and will not become so until an intensive,
closed-door negotiating session among scientists and government leaders in
Stockholm in late September. But if the past is any guide, most of the core
findings of the document will survive that final review.

The document was leaked over the weekend after it was sent to a large group
of people who had signed up to review it. It was first reported on in
detail by the Reuters news agency, and The New York Times obtained a copy
independently to verify its contents.

The Intergovernmental Panel on Climate Change does no original research,
but instead periodically assesses and summarizes the published scientific
literature on climate change.

The draft document “is likely to change in response to comments from
governments received in recent weeks and will also be considered by
governments and scientists at a four-day approval session at the end of
September,” the panel’s spokesman, Jonathan Lynn, said in a statement
Monday. “It is therefore premature and could be misleading to attempt to
draw conclusions from it.”

After winning the Nobel Peace Prize six years ago, the group became a
political target for climate doubters, who helped identify minor errors in
the 2007 report. This time, the panel adopted rigorous procedures in the
hope of preventing such mistakes.

Some climate doubters challenge the idea that the earth is warming at all;
others concede that it is, but deny human responsibility; still others
acknowledge a human role, but assert that the warming is likely to be
limited and the impacts manageable. Every major scientific academy in the
world has warned that global warming is a serious problem.

The panel shifted to a wider range for the potential warming, dropping the
plausible low end to 2.7 degrees, after a wave of recent studies saying
higher estimates were unlikely. But those studies are contested, and
scientists at Stockholm are likely to debate whether to stick with that

Michael E. Mann, a climate scientist at Pennsylvania State University, said
he feared the intergovernmental panel, in writing its draft, had been
influenced by criticism from climate doubters, who advocate even lower
numbers. “I think the I.P.C.C. on this point has once again erred on the
side of understating the degree of the likely changes,” Dr. Mann said.

However, Christopher B. Field, a researcher at the Carnegie Institution for
Science <http://carnegiescience.edu/> who serves on the panel but was not
directly involved in the new draft, said the group had to reflect the full
range of plausible scientific views.

“I think that the I.P.C.C. has a tradition of being very conservative,” Dr.
Field said. “They really want the story to be right.”

Regarding the likely rise in sea level over the coming century, the new
report lays out several possibilities. In the most optimistic, the world’s
governments would prove far more successful at getting emissions under
control than they have been in the recent past, helping to limit the total

In that circumstance, sea level could be expected to rise as little as 10
inches by the end of the century, the report found. That is a bit more than
the eight-inch increase in the 20th century, which proved manageable even
though it caused severe erosion along the world’s shorelines.

At the other extreme, the report considers a chain of events in which
emissions continue to increase at a swift pace. Under those conditions, sea
level could be expected to rise at least 21 inches by 2100 and might
increase a bit more than three feet, the draft report said.

Hundreds of millions of people live near sea level, and either figure would
represent a challenge for humanity, scientists say. But a three-foot rise
in particular would endanger many of the world’s great cities — among them
New York; London; Shanghai; Venice; Sydney, Australia; Miami; and New

Art Deco (Wayne A. Fox)
art.deco.studios at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.fsr.com/pipermail/vision2020/attachments/20130820/6a4c0b02/attachment-0001.html>

More information about the Vision2020 mailing list