More Evidence that "Extreme" Weather Events Will Become the New "Normal"

NY Times
August 11, 2012

Hundred-Year Forecast: Drought
Christopher R. Schwalm, Christopher A. Williams and Kevin Schaefer

These authors deny that climate change should be perceived as a “threat” that will manifest itself sometime in the future; rather, they state that “it is increasingly clear that we already live in the era of human-induced climate change, with a growing frequency of weather and climate extremes like heat waves, droughts, floods and fires.” According to the Fifth Assessment of the Intergovernmental Panel on Climate Change (IPCC), droughts of the length and severity currently being experienced in the United States will be commonplace through the end of the century unless human-induced carbon emissions are significantly reduced. This article reports that the Northern Hemisphere has just recorded its 327th consecutive month in which the temperature exceeded the 20th-century average. This year had the fourth-warmest winter on record, with record-shattering high temperatures in March. And 2012 has already seen huge wildfires in Colorado and other Western states. More than 3,200 heat records were broken in June alone. These authors conclude, along with many others, that:

“[T]his extreme event could become the new normal: climate models point to a warmer planet, largely because of greenhouse gas emissions. Planetary warming, in turn, 
is expected to create drier conditions across western North America, because of the way global-wind and atmospheric-pressure patterns shift in response.”

The problem will be particularly acute in the American West, where the allocation of water resources is a serious and contentious issue. As stated in this article, “[v]irtually every drop of water flowing in the American West is legally claimed, sometimes by several users, and the demand is expected to increase as the population grows.”