Climate Change Science: What We Know

Author(s): Lydia Olander, Rob Jackson, Gabi Hegerl, and Nicole St.Clair

Published: March 2007

download: policy brief (.pdf) >

What We Know 1. Scientists first described how accumulating carbon dioxide levels would raise Earth’s temperatures, in the early 1800s.  2. The Earth is warming.  3. It is very likely current warming is due to human activity.  4. The main uncertainty in predicting future climate change comes from uncertainty in projecting future demography and economics.  5. In addition to warming, there are numerous other impacts of climate change already being observed.  6. We can reduce future warming and its impacts through our actions.