Is Global Warming responsible for weather extremes?
Scientists are trying to understand if the unusual weather in the Northern Hemisphere this winter — from record heat in Alaska to unprecedented flooding in Britain — is linked to climate change. One thing seems clear: Shifts in the jet stream play a key role and could become even more disruptive as the world warms. This winter's weather has been weird across much of the Northern
Hemisphere. Record storms in Europe; record drought in California;
record heat in parts of the Arctic, including Alaska and parts of
Scandinavia; but record freezes too, as polar air blew south over Canada
and the U.S., causing near-record ice cover on the Great Lakes, sending
the mercury as low as minus 50 degrees Celsius in Minnesota, and
bringing sharp chills to Texas. The polar jet stream may be driving a "hemispheric pattern of severe
weather." The story gets tangled because trying to identify long-term trends amid the noise of daily weather is hard. The U.K. Met Office, which keeps a global weather watch, said in a rush report put out in mid-February that we are experiencing a "hemispheric pattern of severe weather," and that the events are linked. The most extreme days of the U.S. cold event, for instance, coincided with some of the most intense storms over the U.K. And physically the connection is through the polar jet stream, which the report said showed a "persistent pattern of perturbations" — in other words, it ran wild. Jet Stream image via NASA Godard Space Flight Center Read more at Yale Environment360. 2014©. Copyright Environmental News Network |