Impact of Global Warming on
Utah's Climate and Weather

by
R. Clayton Brough and David R. James
September 1, 2003

According to the American Meteorological Society (AMS), "There is now clear evidence" that the mean annual temperature of the Earth's surface has been increasing during the past 200 years, during which time greenhouse gases have also increased dramatically-largely due to human activity. Atmospheric scientists generally agree that if greenhouse gases continue to "increase in their concentration" it "will lead to global warming." Various climate models suggest that such warming could amount to "1.4 C to 5.8 C in the next 100 years." This kind of warming would undoubtedly impact local, regional and global climate patterns.

However, what is still "uncertain"--and controversial--is "the magnitude, timing, and regional distribution" of such "anticipated" climate "changes." Also, according to the AMS, while the "rise" in the Earth's "surface air temperatures and subsurface ocean temperatures…over the last several decades"--and especially "the past 50 years"-are "likely mostly due to human activities," scientists "cannot rule out that some significant part of these changes is also a reflection of natural variability" (i.e.: natural climatic fluctuations or cycles). To read more about the AMS statement on global warming and its possible future climatic changes visit the AMS website on Climate Change Research.

The impact of Global Warming on Utah's climate and weather is currently being investigated by several atmospheric scientists. While long-term temperature data indicates that a number of Utah cities have experienced a gradual increase in their mean annual temperatures over the past 100 years (or more), these temperature increases are probably due more to local urbanization and "heat island" effects than to regional climatic changes caused by global warming. However, one cannot ignore the fact that many--if not most--daily and monthly high-temperature records have been set for a number of urban and rural areas of Utah since the 1960's.

How do we feel about Global Warming and the above possibilities outlined by the AMS? Well, as pragmatists and scientists we support reasonable efforts to reduce greenhouse gases while encouraging research that reveals past climatic changes and extremes and their possible future reoccurrences. In fact, we feel Utah's citizens and politicians should "plan for the past"--which could happen again in our future. For example, according to dendroclimatology (or tree-ring studies), portions of Utah and the southwestern United States experienced a fourteen-year drought from 1870 to 1883; and according to weather records these areas experienced an eight-year drought from 1897 to 1904. Could these types of prolonged droughts happen again? We think so. But precisely how long these droughts could last and when they might occur is not yet predictable. Therefore, we feel it's very important that Utah--and other states and regions across the southwestern U.S.--increase water conservation efforts and improve and maintain water storage facilities, because sometime in our future Mother Nature could treat us to a repeat performance of her past climatic changes and extremes.

Click here for more information on Utah's Droughts of the Past 500 Years.