Climate Destabilization Is Real
February 15, 2007
Earlier
this month, the Intergovernmental Panel on Climate Change released a
report that confirmed and refined what scientists already knew: The
recent global warming trend is real, it is caused
primarily by human activities, and we can expect further dangerous warming
of a few degrees if we don't reduce our emissions of greenhouse gases.
Despite the very
high level of confidence that the IPCC placed on this assertion, climate
skeptics refuse to allow themselves to be convinced by the facts. Global
warming deniers--desperate for any information that might contravene the
science--have latched onto this month's colder-than-normal
temperatures that have gripped much of the U.S., particularly the northeast and mid-Atlantic regions. In fact, the temperature
patterns we are currently experiencing are exactly what increasing
greenhouse gas emissions predicts: climate destabilization.
- Weather and climate are two distinct and
separate concepts. To understand why the current cold snap across
the U.S.
is occurring during a global warming trend, one must first understand the
distinction between climate and weather. Climate is the "composite or
generally prevailing weather conditions of a region, as temperature, air
pressure, humidity, precipitation, sunshine, cloudiness, and winds, throughout
the year, averaged
over a series of years." In other words, climate refers to recorded
history. Weather, on the hand, is current events; it refers to the "state
of the atmosphere at a
given time and place." Weather is a snapshot of the climate at any one
instant. Although the two are related, their relationship is indirect.
"The chaotic nature of weather means that no conclusion about climate can ever be drawn
from a single data point, hot or cold. The temperature of one place at one
time...says nothing about climate, much less climate change, much less global
climate change."
- The current trend of snowfall across the
country is consistent with the increased precipitation expected to occur with a
warming globe. Scientists have said "snowfall is often predicted
to increase
in many regions in response to anthropogenic [human-induced] climate change,
since warmer air, all other things being equal, holds more moisture, and
therefore, the potential for greater amounts of precipitation whatever form
that precipitation takes." Based on computer models, a recent study by the
National Center for Atmospheric Research
found, "As Earth gets warmer, large
regions will experience heavier rain and snowfall as weather becomes
generally more intense." The NCAR climate models have predicted that heavier
rains and/or snow would most likely affect regions where large masses of
air converge, including northwestern
and northeastern North America.
- Around the globe, the existence of a warming trend is clear. The long-trend trends present clear evidence that climate change is "real and serious." The IPCC report noted that the "the warmth of the last half century is unusual in at least the previous 1300 years." Of the 12 hottest years on record, 11 have occurred since 1995. The 2006 average annual temperature for the contiguous U.S. was the warmest on record and nearly identical to the record set in 1998, according to scientists at the National Oceanic & Atmospheric Administration's National Climatic Data Center. Residents of the Washington, D.C. metropolitan area have this week been hit by a "gusty wintry wallop" and are experiencing below-average temperatures for this month. Yet, the deviation below the average temperature for February is still less than the above-average deviation that D.C. residents experienced during the month of January. While the climate change trend is clear, the weather patterns at different moments in time will be hard to predict.
