Many citizens and policymakers are confused about whether climate change should be taken seriously, largely reflecting debate occurring within the media. However, the science is clear: This is one of the most important issues confronting humanity in the 21st century. The Intergovernmental Panel on Climate Change, comprising hundreds of the top scientists studying climate change, recently concluded, "There has been a discernible human influence on global climate". The IPCC assessment also supports the conclusion that there is a high probability of significant global climate change (including global warming) over the coming decades.

Human activities are increasing the concentration of carbon dioxide and several other greenhouse gases, raising concerns that the Earth may warm, on average, by 2-11 F over the next century without significant policy actions to reduce greenhouse gas emissions. Increases in average global temperature over the last decade already appear to be outside the normal range of temperature changes for the last thousand years. Scientists are also documenting changes in alpine glaciers, sea ice, seasonal snow cover, and the length of the growing season that strengthen the evidence that the climate is warming. There also appear to be larger than normal changes in precipitation, cloudiness, temperature, and rainfall.

Studies have shown that human health, ecological systems, coastal systems, and socioeconomic sectors such as hydrology and water resources and food and fiber production are sensitive to changes in climate as well as to changes in climate variability. The changes in climate projected for this century could have significant impacts in all these areas. Meanwhile, the nations on our planet struggle with how to develop policy to prevent the large changes in climate being projected. It is clear that we cannot prevent all of the changes in climate, but will need to adapt to some degree to a warmer Earth.

In this talk, I will discuss the current understanding of climate change and associated issues, the potential impacts, particularly on the Midwest, and some of the questions needing to be addressed towards developing meaningful policy to slow down the rate of climate change.

ANL Physics Division Colloquium Schedule