Climate model predicts heatedly hot decade
Pastor Dale Morgan
Climate model predicts heatedly hot decade
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The blistering summer sun sets over Islamabad, Pakistan, in July. Global
warming has contributed to about a one-degree rise in average worldwide
temperatures over the past century.
By Dan Vergano, USA TODAY
The next decade will be a hot one, according to scientists unveiling the
first 10-year projection of global warming.
The climate projection, published today in the journal Science, suggests
that a natural cooling trend in eastern and southern Pacific ocean
waters has kept a lid on warming in recent years.
And it will continue to do so, scientists say, but not for long.
The projection spans 2006 to 2015. "At least half of the years after
2009 are predicted to be warmer than 1998, the warmest year currently on
record," the researchers say in their report.
Globally, that means a typical year will be about half a degree warmer
than in the previous 10 years, a projection in line with findings this
year by the Intergovernmental Panel on Climate Change. The panel's
report, the work of thousands of scientists, also predicts steadily
rising temperatures.
The decade covering 1996 to 2006 contained the warmest years ever
recorded, with temperatures peaking in 1998 and nearly reaching that
height in 2005.
The significance of the new study is that over the last century, global
warming has contributed to about a one-degree rise in average
temperatures. The new projection suggests that in a short time — just
one-tenth of that time span — the average temperature will be another
half a degree higher still.
The climate models used by scientists normally cover a century. One that
covers a decade is an innovation that will allow more precision, says
the study team led by Doug Smith of the United Kingdom's Hadley Centre
for Climate Prediction and Research.
Improved regional projections, including a prediction that there will be
a general warming over North America, have resulted from combining fresh
weather data with the state-of-the art climate model, Smith says.
"In the climate-modeling world, a short prediction is considerably
harder than a long one," says climate researcher John Drake of the
Energy Department's Oak Ridge (Tenn.) National Laboratory. That's
because natural variability in weather has a stronger effect in the
short term than when averaged out over 100 years.
But the ability to produce accurate, 10-year predictions will be
important for world leaders charged with making climate-related
decisions, Drake says.
Global warming is an increase in atmospheric temperatures tied to
industrial activities, particularly the burning of fossil fuels like
coal that release such heat-trapping "greenhouse" gases as carbon dioxide.
The creators of older climate models are most confident about their
projections for the years around 2040, making a new decade projection
especially important to politicians and other decision-makers, agrees
Gavin Schmidt of NASA's Goddard Institute for Space Studies in New York.
"If this works, it is a good step forward," he says, but cautions that
ocean temperature measurements vital to the decadal model are limited.
Such measures are now fairly low tech, usually involving boats and
thermometers.
Improved ocean measurements should soon improve the reliability of the
decadal forecast, Smith says. And he adds one caveat the model can't
account for. "Any major volcanic eruptions would cool the climate
compared with our forecast."
Climate models have critics, such as renowned Princeton physicist
Freeman Dyson. But the Hadley Centre projections have been run
backwards, so-called "hindcasts" that closely reproduce climate in past
decades to check accuracy.