New observations and research have increased our understanding of past, current, and future climate change. The 4th National Climate Assessment confirms prior assessments in concluding that the climate on our planet, including the United States, is changing, and changing rapidly. Observational evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans. Documented changes include surface, atmospheric, and oceanic temperatures; melting glaciers; disappearing snow cover; shrinking sea ice; and rising sea level. Many lines of evidence demonstrate that human activities have been the dominant cause of the observed warming since the mid-20th century. Changes in the characteristics of extreme events are particularly important for human safety, infrastructure, agriculture, water quality and quantity, and natural ecosystems. Some extremes have already become more frequent, intense, or of longer duration, and many extremes are expected to continue to increase or worsen, presenting substantial challenges. The Earth’s climate is projected to continue to change over this century and beyond. This presentation provides an overview of the science of climate change from the 4th National Climate Assessment, and discusses what this means for the U.S. and our planet.
Donald J. Wuebbles is the Harry E. Preble Professor of Atmospheric Science at the University of Illinois where he has been since 1994. He is also a Presidential Fellow at the University of Illinois, with the aim of helping the university system develop new initiatives in urban sustainability. From 2015 to early 2017, Dr. Wuebbles was Assistant Director with the Office of Science and Technology Policy at the Executive Office of the President in Washington DC. His other roles on campus have included Director of the Environmental Council and the School of Earth, Society, and Environment; he has led the Intergovernmental Panel on Climate Change (IPCC) through a variety of reports and initiatives, and is the
Lead author of the U.S. National Climate Assessment.
