The topic of climate change inspires a lot of debate. At NASA, it has also inspired a lot of science. NASA scientists examine the Earth's climate and how it is changing -- gaining knowledge through decades of satellite observations, powerful computer models and expert scientific analysis. This NASA Google+ Hangout on Mon., Sept. 30, at 12 p.m. EDT, caps a month-long campaign called Ask A Climate Scientist, #askclimate, designed to connect NASA climate scientists with the public to answer pressing questions about climate change. The Hangout takes place after the Sept. 27 release of the Summary for Policymakers report by the U.N.'s Intergovernmental Panel on Climate Change, #IPCC, a summary of the international science community's consensus view of climate change science. The #NASA scientists scheduled to take part in the Hangout contributed to the current and previous IPCC's Working Group 1, which is focused on the measurement and future projections of climate change. Ask your questions about climate science and the IPCC report in the comments section here on Google+ or in the YouTube comments section during the live broadcast of the Hangout or via Twitter using #askclimate. The scientists participating in the Hangout include: • Ralph Kahn, NASA's Goddard Space Flight Center, Greenbelt, Md., reviewer of Chapter 7: Aerosols, IPCC Working Group 1: Physical Science Basis • Eric Rignot, NASA's Jet Propulsion Laboratory, Pasadena, Calif.; and the University of California -- Irvine, lead author of Chapter 4: Observations: Cryosphere, and reviewer of Chapter 13: Sea Level Change • Drew Shindell, NASA's Goddard Institute for Space Studies, New York, N.Y., coordinating lead author of Chapter 8: Anthropogenic and Radiative Forcing, IPCC Working Group 1: Physical Science Basis; drafting author of IPCC Summary for Policymakers • Bruce Wielicki, NASA Langley Research Center, Hampton, Va., contributor to IPCC 2007