Hottest year on record, 1998 part of accelerating
trend, experts say
By Seth Borenstein
Copyright 1999 Houston Chronicle
January 12, 1999
WASHINGTON - Two federal agencies announced on Monday that 1998
was the hottest
year on record, but the pattern is even more extensive than that,
experts say.
The 1990s will go down as the hottest decade on record, a
Knight Ridder
statistical analysis of 119 years of global
temperatures indicates.
NASA, then the National Oceanic and Atmospheric
Administration announced Monday
that 1998 was the hottest year ever at 58.1 degrees - 1.2 degrees
hotter than
normal.
But the real story is the rapid acceleration of the warming
since 1976, which
has resulted in the hottest decade ever, Tom Karl, director of the
National
Climatic Data Center, said Monday.
The long heat wave has scientists working to assess how
much of it is caused by
increases in man-made greenhouse gasses and how much is natural,
produced by a
spate of El Nino warmings of the Pacific Ocean.
"This is a signature that the
global warming we expected is rearing its
head," said Kevin Trenberth, climate analysis chief at the
National Center for
Atmospheric Research, a Colorado institution funded by the National
Science
Foundation.
Tim Barnett, a leading
climate change researcher at the Scripps Institution for
Oceanography at the University of
California, San Diego, called the decade record
"the canary in the mine, so to speak."
But others see a different picture.
William Gray, a Colorado State University atmospheric
scientist who made his
reputation the past 20 years predicting how strong hurricane
seasons would be, theorizes that the world has been warming up
naturally, not
artificially.
"Climate change has always been with us. You can't
deny
climate change," Gray said.
"Whether humans are affecting it much, we don't know."
Simon Mason, another Scripps research scientist, noted:
"The debate is really not about whether the globe is
warming up. It would be really foolish to argue that fact. The
debate is: What
is causing the warming? Is it a case of us polluting the
atmosphere, or is it a
case of natural variability?"
The first nine years of the 1990s have been so hot that
1999 would have to
average at least 2 degrees colder than normal to keep the
decade from being a record, according to the analysis of historical
temperature
data.
And that is pretty much impossible, experts said, because
the temperature
doesn't change that rapidly.
National Climatic Data Center records show that when global
land and sea
temperatures are averaged out monthly, they didn't vary much -
until
recently. From 1880, when record keeping started, to 1980, yearly
averages
varied at most about half a degree from normal. But that changed in
the 1980s
and 1990s.
The 1990s as a decade, so far, is seven-tenths of a degree
warmer than the
global average for the last
119 years. That's not only hotter than normal, it's much hotter
than normal.
The previous hottest decade, the 1980s, was only
four-tenths of a degree hotter
than normal and before that the hottest decade, the 1940s, was less
than
two-tenths of a degree above normal.
And on a yearly
basis, the change is even more pronounced. Not including December,
1998 was 1.2
degrees hotter than the 11-month normal, and 1997 as a year was
nearly a degree
above normal. Also, 1990 and 1995 were nearly eight-tenths of a
degree above
normal - extremes unheard of until
recently.
The normal average yearly temperature for the world is 56.9
degrees, according
to U.S. statistics, gathered from land and sea stations around the
world.
"The thing to bear in mind is that the warming has
been very large and quite
rapid," said Mason, the Scripps research scientist.
David Easterling, a scientist
at the National Climatic Data Center, said:
"When you start looking at some of the unprecedented events
that have occurred,
16 months in a row that set a record, the evidence is really
starting to mount
that something is happening."
Most leading meteorologists are convinced the warming is
caused by human
pollution -
carbon dioxide causing a runaway greenhouse effect. Others say this
is
perfectly natural. That issue is being debated at the American
Meteorological
Society's 10th symposium on global climate studies in Dallas this
week.
Gray, the Colorado State scientist, said his studies show
that the
climate
changes roughly every 30 years and that change correlates to
changes in ocean salinity
in the north Atlantic Ocean.
This is the great Atlantic conveyor belt theory, in which
the water in the
world's oceans churns from the cold bottom to the warmer surface at
different
rates in different
decades. The slower the conveyor belt moves, the warmer the surface
water is.
The warmer the surface water is in the Pacific, as in El Nino, the
warmer the
rest of the world.
But the conveyor belt, which had been slow for 30 years,
started speeding up
four years ago, and we will soon feel the
effects of a natural climate shift, Gray said.
"I'm predicting in the next 20 to 25 years, the globe
is going to slowly cool," he added.
"If it doesn't happen, I'll jump off a Colorado
mountain."
Comments on this posting?
Click here to
post a public comment on the Trash Talk
Bulletin Board.
Click here to send a private
comment to the Junkman.
Material presented on this home page constitutes opinion of
Steven J. Milloy.
Copyright © 1998 Citizens for the Integrity of
Science. All rights reserved on original material. Material
copyrighted by others is used either with permission or under a
claim of "fair
use." Site developed and hosted by WestLake
Solutions, Inc.