Whatever happened to the hiatus in warming?
Global warming slowed in 1999 even though greenhouse gas emissions continued to rise. This “hiatus in warming” has not been explained by greenhouse warming models. Since the El Nino of 1998, the Pacific Ocean had been in a curiously extended la Nina state that kept the Pacific Ocean’s surface cool. California had its worst ever drought, and we Californians began to hope for another giant El Nino. The big one finally came in 2015, and California’s Sierra Nevada got record snowfall that winter. The drought seemed over. The hiatus seemed over too, since El Nino warming increased the global temperature. But the hiatus may be coming back. La Nina cooling has returned and 2017 has been one of California's driest years-with unusual wind patterns and huge wild fires. Clearly there is something somewhere we do not understand. New research emphasizes the extraordinary loss of Arctic sea ice that also began around 1999. Arctic Ocean warming may be setting up upper atmosphere winds that are changing the El Nino/La Nina cycle. If so, California is in for more surprises until the sea ice goes away altogether.
Seminar 1 of the 2018 Climate Change Seminar Series
Date: Thursday 18 January 2018
Venue: Plumb Auditorium, Christ's College, with a reception to follow (map)
Networking and drinks will follow.
Professor Charles Kennel, Director Emeritus of the Sripps Institution of Oceanography
For information on other seminars in this series, please click here.
(Banner image Harnessing Nature by Tommy Clark CC)