The observational evidence that our Earth is warming is overwhelming and unmistakable. Earth scientists agree that in the past 200-plus years, human activity has been a significant contributing factor to the observed increase in mean global temperatures. Scientists cannot explain this increasing temperature trend without incorporating human impacts, primarily the burning fossil fuels.
Svante Arrhenius, a Swedish scientist, was probably the first scientist to propose that burning fossil fuels could modify our global temperatures. He recognized that carbon dioxide (CO2), a byproduct of burning carbon-based substances such as natural gas, gasoline and oil, is like a greenhouse gas and that increasing the quantity of CO2 in the atmosphere through human activities could lead to a warmer Earth. He made this estimate in 1896. So, we have been aware of the fundamental physics of global warming for over 100 years.
This observed warming impacts ecosystems across the globe, including those in Wisconsin and the Great Lakes region.
The warmer winters enable some invasive species to survive the normally harsh season. As our river and lake waters warm, they become a less favorable environment for native cold-water fish species.
The growing season has lengthened by about one to four days per decade during the past 40 years in the Northern Hemisphere, especially at higher latitudes. This can have some positive impacts on agriculture and home gardening.
The duration of ice cover on lakes has decreased by about two weeks over the 20th century in the mid and high latitudes of the Northern Hemisphere. This reduces the ice fishing time enjoyed by so many Wisconsin families. The reduced time the ground is frozen impacts wintertime harvesting of our forests.
Instead of debating a well-known and well-understood fact concerning our changing climate, it is time for a healthy debate regarding what actions we should take in response to this reality and the associated environmental and societal impacts.
President Abraham Lincoln, who founded the National Academy of Sciences the same year he so eloquently extolled the virtues of “government of the people, by the people, and for the people” at Gettysburg, would surely condemn the imposition of willful ignorance on an issue of public concern.
No government, local or national, should intentionally obfuscate a science issue on which so many hard-working scholars have rendered conclusions. The change to the Wisconsin Department of Natural Resources’ website in reference to climate science this week is shameful.