Global Warming and Warm Weather: Connected?
Scientists Say Current Patterns Fit Into Overall Predictions
By BILL BLAKEMORE
Jan. 6, 2007 � It was expected to reach into the 70s today in New York
City. Cherry blossoms were blooming in Washington, D.C.
Is there a connection between the January heat wave that is sweeping
the East Coast and man-made global warming?
Scientists say yes � in this way: What they know for sure is the warm
winter fits the pattern, exactly, that has long been predicted for
manmade global warming of more and more frequent unseasonable warm
While there were freak weather events like this in the past, even
before the Industrial Age started pumping out more greenhouse gases,
they were rare.
But in recent decades they have increased.
There has been "a fairly rapid rise of globally average temperatures,
also temperatures in the United States, since about the mid-1970s,"
said David Easterling of the National Climate Data Center.
The records from the National Climate Data Center show that over the
last 55 years, especially the last 20, the number of unusually warm
days and warm nights has steadily increased.
The supercomputers that predicted all this decades ago have grown even
more powerful. What do they project for the years immediately ahead,
if greenhouse gas emissions are not drastically cut worldwide?
"Over the next two or three decades, we will see a trend of just more
frequent warm spells and less frequent cold snaps," said Jerry Meehl,
But these changes are not limited to just warm weather. Colorado's
third big snowfall in a month also fits a pattern long predicted for
The warmer the air, the more moisture it can hold, which leads to
heavier precipitation of rain or snow.
Scientists say there are always immediate causes contributing to warm
spells, such as the current warm El Nino patch that's appeared again
in the Pacific.
But El Nino, like everything in earth's climate, is influenced one way
or another by manmade global warming.
Climate scientists in the United Kingdom calculate that the current El
Nino, combined with the additional warming effect of the increasing
manmade greenhouse gases mean a better-than-even chance that 2007 will
be the hottest year on earth since records have been kept.
Already, the 10 hottest years on record have been in the past 11 years.