USING WHAT WE KNOW
                Extreme weather events make the news. They bring to mind similar weather experiences from our past and we hear old-timers and newscasters tell of times farther back than we can remember. Observing local weather, although related, is different from understanding changes in global climate.
                “As with any field of scientific study, there are uncertainties associated with the science of climate change… Some aspects of the science are known with virtual certainty because they are based on well-known physical laws and documented trends.”  Virtual certainty conveys a greater than 99% chance that a result is true.
                Scientists know that 1) human activities are changing the composition of Earth’s atmosphere; 2) human activities, such as burning fossil fuel, have resulted in the buildup of greenhouse gases in the atmosphere; 3) Warming about 1.0 to 1.7 degrees F. has occurred from 1906-2005 in both the Northern and Southern Hemisphere; 4) major greenhouse gasses emitted by human activities remain in the atmosphere for periods ranging from decades to centuries and will rise over the next few decades; 5) increasing greenhouse gases tend to warm the planet.
                “A growing number of scientific analyses indicate, but cannot prove, that rising levels of greenhouse gases in the atmosphere are contributing to climate change…Scientists anticipate (with a greater than 90% chance that the results are true) that as atmospheric concentrations of greenhouse gases continue to rise, average global temperatures and sea levels will continue to rise as a result and precipitation patterns will change.” (www.epa.gov/climatechange)
                Important scientific questions remain about how much warming will occur, how fast it will occur, and how the warming will affect the rest of the climate system including precipitation patterns and storms. Scientific knowledge is always in transition being informed by more accurate data and new understandings.
                To address the uncertainties of climate change, thirteen government agencies are participating in the U.S. Global Change Research Program (USGCRP). “In 2011 a decadal strategic planning process has begun that will restructure the program to improve research for decision making and to better meet the needs of the Nation…“The new USGCRP will not only provide the basic knowledge of climate and global change, but it will strive to support and effectively communicate with societal decision makers.” The planning process included input from listening sessions that were held around the country in 2009. A public comment period was held from May through September 2011. The final plan is to be released in December 2011. (www.globalchange.gov)
                To adjust to the changing seasons with which we are familiar, we depend on the short and long range weather forecasts of meteorologists. For understanding climate, changes in weather patterns around the earth, and making adjustments to adapt to consequences of these changes, we must depend on climatologists to inform us. Stay tuned.

Della Moen, Earth Team Volunteer, NRCS/Stephenson Soil and Water Conservation District, an equal opportunity provider and employer, 09/14/11/11 (for publication on 09/17/11 in the Journal Standard, Freeport, Illinois.  Della can be reached at info@stephensonswcd.org