The University of Arizona

Weathering Climate

April 15, 2011
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I’ve been hearing about a couple of prickly mountain lions spotted in Sabino Canyon near Tucson, more frequent observations of birds with talons in cities, and increased javelina sightings near dwellings. All are telltale signs of mounting drought impacts on the ecosystem. Not since November, 2007, have drought conditions been as severe as they are currently in parts of Arizona.

The culprit of the drought conditions is not the whims of the weather (although they play a role) but rather the cooler-than-average sea-surface temperatures in the eastern Tropical Pacific Ocean that have been parked in the region since about last July: the La Niña event. In other words, the drought has more to do with climate changes. The connection between climate and weather is often misunderstood, with serious ramifications. Slowing and reversing warming and adapting to changes will be built on proper understanding of climate’s role in year-to-year weather.

If effective action requires popular support, trends in perception about climate change are going the wrong way. According to an article in Nature Climate Change, Gallup found that only 52 percent of people polled in 2010 believe global warming is occurring, down from 65% in 2008. Other studies report similar results (see here). This is in sharp contrast to the beliefs of earth scientists: Peter Doran and Maggie Zimmerman present Gallup survey results in Eos, Transactions, American Geophysical Union (2009) that state more than 95% of climate scientists actively publishing in the field believe that human activity is a significant contributing factor in changing global temperatures.  

The reason for declining trends in public perception is no doubt complicated. Climate change likely takes a back seat to more immediate problems such as the economic crisis and armed conflicts. Part of the explanation also has to do with how well-informed the public is, and there is a lot more work to be done on this front.  This became evident to me after reading the Nature Climate Change article, which implies many people conflate weather and climate, the distinction of which is a fundamental earth science concept. The difference between weather and climate is time. While weather pertains to the atmospheric conditions over a short period of time, climate relates to how the atmospheric conditions change over relatively long periods. The average June temperature calculated over 30 years, for example, is a measure of climate. So is the average number of summer days with temperatures over 100 degree F. Yesterday’s maximum temperature or total precipitation, on the other hand, is a measure of weather. This may sound like a simple distinction, but it is confusing to many in part because the exact time duration at which “weather” becomes “climate”—one week? Twenty days? Thirty days?—is nebulous.”.

Recent research suggests that people are more likely to believe in and feel concern about global warming during days that feel warmer than usual, while cold-feeling days elicit the opposite response (see here). This basically implies that many people living on the East Coast and in Western Europe, which were slammed with frigid Arctic air in the past two winters, are not concerned that our current fossil-fuel-burning path has consequences. Nor do they likely understand that those same cold snaps seem to be related in part to the strength of the Arctic Oscillation, which is a climate phenomenon (see here and here). I have also experienced this misunderstanding first hand. People have emphatically cited the cold winters in the East as evidence against global warming during a few of my public climate presentations.

With drought conditions on the march, there may be a silver lining to the expanding drought conditions. People focus their attention during dire situations, which may create a brief window to discuss and educate people about weather and climate. And since most people find climate change psychologically distant, and something that will affect other people in other places and times, grounding our conversations in current events is imperative. Using the capering cats or dive-bombing eagles as examples of the impacts of climate on the landscape will go a long way to developing a better informed citizenry.