Climate Will Not Increase Dramatically, Study Indicates
January 15, 2002--
Some global warming scenarios envision temperatures rising
over the next 100 years to the point that plants will produce less
and seas will rise dramatically, swamping coastal cities.
scenarios suggest only slight global temperature increases with
coastal zones remaining high and dry and plant production actually
less dramatic one, the one that "looks more like the same world
as today," is right, says Virginia State Climatologist Patrick
Michaels. He has published a paper in the current issue of the journal
Climate Research that calls into question the high end of the temperature
ranges projected by the United Nations’ Intergovernmental
Panel on Climate Change (IPCC), of which Michaels is a member.
rate of warming will not be much different than it was over the
last 30 years," said Michaels, a professor of environmental
sciences at the University of Virginia.
most climate models produce a constant rate of future warming, that
rate varies dramatically. Michaels’ research was designed
to determine which of these rates are more likely than others.
uses nature itself as his model, comparing past real temperature
rates to those predicted in computer models.
has been integrating the response to greenhouse effect changes for
nearly a half-century, while models have been producing diverse
projections,” Michaels notes.
years ago the IPCC produced its third assessment report, which indicated
a global rise in temperatures of 1.4 to 5.8 degrees Celsius for
1990 to 2100.
new independent study indicates the most likely value is around
1.6 degrees Celsius, near the low end of the IPCC range He used
an assortment of data to produce a range of possible temperatures
for the period, and all were substantially less broad than the IPCC’s
one scenario, he used data from recent studies that closely examine
the assumptions made about climate behavior in the U.N. report and
found a range of warming of 1.1 to 2.8 degrees Celsius.
using data of actual climate change rates during the past 25 years
of greenhouse warming, and projecting it out to the year 2100, he
found a range of 1.5 to 2.6 degrees Celsius.
all models produce a constant rate of warming,” Michaels said.
"So why not let nature choose that rate?”
he factored both aspects of his study together, he found a range
of 1.0-1.6 degrees Celsius.
by adjusting the averages of a range of climate models to reflect
actual observed changes in temperature in nature, he found a warming
range of 1.3-3.0 degrees Celsius, with a central value of 1.9 degrees
consistency of these somewhat independent results encourages us
to conclude that 21st century warming will be modest and near the
low end of the IPCC's third assessment report projections,"
says that much of the data in the panel's report is based on older,
less accurate studies that take into account neither what has actually
occurred in nature during the past century nor the more refined
and accurate independent findings of more recent studies.
paper looks at what should have been examined in the IPCC report,"
he said. "We should be listening to nature talking."
also said society is producing more fuel-efficient machinery and
will continue to do so throughout this century, further reducing
the likelihood of dramatic warming.
is why we shouldn't rush policy decisions before we have strong
and clear evidence that our projections are sound," Michaels
said. "In this study we demonstrate that the IPCC's evidence
for intense warming projections is weak, but the evidence for the
low end of their range is very strong”.
full article can be accessed at:
Fariss Samarrai, (434) 924-3778