Professor O. Brian Toon
February 7, 2012
7:30-8:30, Kane Hall, Room 210
Dr. Owen Brian Toon
Professor, Department of Atmospheric and Oceanic Sciences, University of Colorado
Lecture: "The Anti-Greenhouse Effect Along the Spiral of Geologic Time"
This event is past.
Microscopic particles in the atmosphere including desert dust, sea salt, volcanic debris, air pollution and bio-particles are found everywhere on Earth. The particles nearly counterbalance the climate changes from greenhouse gases, sometimes shut down airports, and create a substantial health risk when breathed. More severe effects have occurred in the past.
For the first half of its history, Earth may have been enveloped in an organic haze, blocking the view of the surface from space, providing a UV shield and food for the biosphere. Earth nearly froze over several times, possibly triggering the origins of complex life about 600 million years ago, perhaps due to our passage through an interstellar dust cloud. About 65 million years ago particles generated from an asteroid collision in the Yucatan Peninsula broiled the dinosaurs alive, burned most of the extant land biota then froze the rest, and so diminished sunlight reaching the surface that the food chain in the oceans collapsed. In the past 100,000 years particles from giant volcanic eruptions may have nearly eliminated our species, and more recently caused migrations and stock market collapses. The future will see more events like these and possibly worse. The smoke generated in a nuclear war could kill the majority of the people on Earth. In the near future we may be forced to moderate the climate using particles to offset rising temperatures and sea levels due to greenhouse gases. If this geo-engineering to rescue our planet isn’t needed now, it eventually will be tens or hundreds of millions of years from now as the sun swells, brightens and threatens to turn our planet into an uninhabitable cinder.
Did Earth look like Titan
for half of Geologic time?
Could we all starve after a nuclear war?
About the Speaker
Dr. Toon is a director and professor in the Department of Atmospheric and Oceanic Sciences and a fellow at the Laboratory for Atmospheric and Space Physics at the University of Colorado. Currently, Dr. Toon is active in the following research areas: theoretical studies of stratospheric volcanic clouds and aerosols and of polar stratospheric clouds; theoretical studies of cirrus, stratus and cumulus clouds, and of direct and indirect effects of aerosols on climate; experimental investigations of stratospheric ozone loss, cirrus, stratus and stratospheric clouds, indirect effects of aerosols on clouds; and theoretical investigations of planetary atmospheres, with the goal of understanding the clouds and climates of the terrestrial planets. His research on the asteroid impact that killed the dinosaurs led to the discovery of nuclear winter due to the major decrease in temperature. He is a fellow of the American Meteorological Society and the American Geophysical Union.
Professor Peter V. Hobbs
Hobbs Endowed Lectures
Description of Lectureship
The purpose of the Peter V. Hobbs Memorial Endowed Lectureship in Experimental Meteorology shall be to sponsor open lectures in the field of experimental meteorology. Peter Hobbs felt strongly that the furthering of science must be nurtured through the open exchange of ideas amongst scientists. To that end, he planned to fund an Endowed Lectureship in Experimental Meteorology for the Atmospheric Sciences Department at the University of Washington where he had worked for 42 years.
Peter Hobbs was deeply involved all his working life in the field of experimental meteorology which ranges from the microscale, through the mesoscale, up to the global scale, and includes both the physics and chemistry of the atmosphere. The common threads in this field are the ubiquitous roles played by aerosols, clouds and precipitation in the atmosphere.
The gift to establish this endowed lectureship was made in loving memory of Peter by his wife and three sons.
The CARG's Convair-580 research
aircraft in Pietersburg, South Africa,
during the SAFARI-2000 Field Project.
Photo: NASA Dryden Flight Research Center
Hobbs Career Information
Professor Peter V. Hobbs was a faculty member of Atmospheric Sciences at the University of Washington from 1963 to 2005. He received his B.Sc. and Ph.D. degrees in Physics from the Imperial College of Science and Technology, University of London, in 1960 and 1963, respectively. Director of the Cloud and Aerosol Research Group at the University of Washington from 1963 to 2005.
Principal research interests were cloud and precipitation physics, mesoscale meteorology, atmospheric chemistry and air pollution.
In addition to his steady stream of discoveries about all aspects of clouds—published in 340 papers—Hobbs advised more than 50 graduate students after arriving at the University of Washington, repopulating the field of atmospheric physics.
None of this would have been possible had Hobbs not had a talent for stringing together the funds for aircraft for 40 years, starting with a WWII vintage bomber previously owned by eccentric billionaire aviator Howard Hughes.