The “pause” in global warming is temporary. It is an illusion. It is caused by volcanoes…no, by the heat being buried in the Pacific Ocean…no wait, the Atlantic Ocean. The latest research now points to winds in the Pacific by way of explaining the pause in the rising rates of surface temperatures. According to Climate Central reports, they are apparently also responsible for drought in the western United States:
Strong trade winds have been forcing heat into ocean depths, contributing to a temporary slowdown in land surface warming over the past 15 to 20 years that some have called a warming hiatus, pause or false pause. New research published in the Journal of Climate has gone further — implicating those winds in stubborn droughts afflicting Western states. […]
Delworth and his colleagues looked at the role strong winds blowing out of the east have played in pushing warm water across the Pacific and eventually forcing it below the surface. Meanwhile, cooler-than-normal water has risen up to replace it in the eastern Pacific, a mechanism that has temporarily helped slow the rate of warming on land, despite continued global warming. (Globally, 2014 was the hottest year on record, and 13 of the hottest 15 years have been recorded since 2000.)
The ocean and atmosphere are intimately linked, so the story doesn’t just stop in the watery depth of the Pacific. Delworth’s analysis shows the precipitation deficit that has driven drought in the western U.S. since the early 2000s is due to these changes in the Pacific region. In particular, ocean conditions have helped set up a ridge pattern that deflects storms into Canada.
None of this makes us doubt the underlying science of climate change. It’s fairly easy to demonstrate that greenhouse gases raise surface temperatures, and that humanity has been emitting these gases at alarming rates of late. However, this warming slowdown (and the myriad attempts to explain it) does remind us that the study of complex systems like the human body or the earth’s climate is extremely difficult and that scientists develop, test, discard and contest many hypotheses on the way to truth.
We may never fully understand our climate; there are a mind-boggling number of variables and relationships that continue to defy even our best climate models. That doesn’t mean we should stop trying, nor does it mean that we shouldn’t craft policies based on what we do know. However, the green movement needs to understand that by selling global warming as “settled science,” it opens itself up to criticism when scientists fail to predict what comes next.