By Mark Fischetti, Scientific American. An article relevant to GSS
Climate Change chapter 8. Excerpt: If you’ve followed the U.S. news and
weather in the past 24 hours you have no doubt run across a journalist
or blogger explaining why it's difficult to say that climate change
could be causing big storms like Sandy. …The hedge expressed by
journalists is that many variables go into creating a big storm, so the
size of Hurricane Sandy, or any specific storm, cannot be attributed to
climate change. That’s true, and it’s based on good science. However,
that statement does not mean that we cannot say that climate change is
making storms bigger. It is doing just that—a statement also based on
good science, and one that the insurance industry is embracing, by the
way. … Hurricane Sandy got large because it wandered north along the
U.S. coast, where ocean water is still warm this time of year, pumping
energy into the swirling system. But it got even larger when a cold Jet
Stream made a sharp dip southward from Canada down into the eastern U.S.
…Here’s where climate change comes in. …Recent research by Charles
Greene at Cornell University and other climate scientists has shown that
as more Arctic sea ice melts in the summer—because of global
warming—the NAO [A climate phenomenon called the North Atlantic
Oscillation] … more likely … makes the Jet Stream … move in a big, wavy
pattern across the U.S., Canada and the Atlantic, causing the kind of
big southward dip that occurred during Sandy. Climate change amps up
other basic factors that contribute to big storms. For example, the
oceans have warmed, providing more energy for storms. And the Earth’s
atmosphere has warmed, so it retains more moisture, which is drawn into
storms and is then dumped on us. … if you’re a regular Scientific
American reader, you might recall that another well-regarded scientist
predicted behemoths such as Sandy in 2007. The article, by Kevin
Trenberth, a senior scientist at the National Center for Atmospheric
Research, was presciently titled, "Warmer Oceans, Stronger Hurricanes."
Trenberth’s extensive analysis concluded that although the number of
Atlantic hurricanes each year might not rise, the strength of them
would. … Munich Re, one of the world’s largest reinsurance firms, issued
a study titled "Severe Weather in North America.” …the report
identified global warming as one of the major culprits: “Climate change
particularly affects formation of heat-waves, droughts, intense
precipitation events, and in the long run most probably also tropical
cyclone intensity." Read the full article: http://blogs.scientificamerican.com/observations/2012/10/30/did-climate-change-cause-hurricane-sandy/ |
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