APL Colloquium

January 18, 2008

Colloquium Topic: Global Warming and the Human Condition

Global warming is primarily the result of human-caused emissions of greenhouse gases. These emissions have increased rapidly since 2000 due to global economic growth, the world's economy becoming more carbon intense (more carbon being emitted to produce each dollar of wealth), and deterioration in the land and ocean's ability to absorb carbon from the atmosphere. This is causing an acceleration of the melting of Earth's ice and rising sea level, an increased frequency and duration of extreme weather events, deleterious affects on the world's oceans and much more. It now appears that the increased emissions will cause the atmospheric CO2 and temperature to reach dangerous levels (~450 ppm and ~2º C temperature anomaly) causing critical conditions in many parts of the world by mid-century. It will take extraordinary measures to lower the greenhouse gas emissions enough to prevent a catastrophic rise in atmospheric CO2 and temperature (~650 ppm and ~4º C temperature anomaly) by the end of the century. Currently we are on a carbon emission trajectory that, if maintained, will result in a greenhouse gas abundance of over 900 ppm and a temperature anomaly >6º C (Hot House conditions) by the end of the century. We may now be on the toe of a non-linear response of the climate system. This talk will also discuss other aspects of global warming including ways of mitigating the problem.

Colloquium Speaker: Robert Strom

Robert Strom is Professor Emeritus of planetary sciences in the Department of Planetary Sciences and the Lunar and Planetary Laboratory at the University of Arizona, Tucson, Arizona. He is the former Director of the Space Imagery Center; a NASA Regional Planetary Image Facility. His main fields of expertise are planetary geology and geophysics, and the planetary impact cratering record. Strom has been a visiting Senior Research Fellow at the University of London Observatory, and visiting professor at the Institute for Space Astrophysics in Rome, Italy, and at the Dept. of Science, University d'Annunzio, Pescara, Italy. Strom was a member of the Lunar Operations Working Group for the Apollo 8, 10 and 11 missions to the Moon, Deputy Team Leader of the Imaging Team for the Mariner 10 mission to Venus and Mercury, and a member of the Imaging Team for the Voyager missions to Jupiter, Saturn, Uranus, and Neptune. Currently he is a member of the Science Team on the MESSENGER mission. Strom has studied climate change on Earth for the past 15 years. He has just published a book on the subject of global warming and its consequences, titled Hot House: Global Climate Change and the Human Condition.