Climate Research
Saturn's moon Titan as seen by the visual and infrared mapping spectrometer after closest approach on a July 22, 2006 flyby."The ironic thing on Titan is that although it's much colder than Earth, it actually acts like a super-hot Earth rather than a snowball Earth, because at Titan temperatures, methane is more volatile than water vapor is at Earth temperatures," says Ray Pierrehumbert. Pierrehumbert and former graduate student Jonathan Mitchell go so far as to call Titan's climate "tropical," even though it sounds odd for a moon that orbits Saturn more than nine times farther from the sun than Earth.
Of the 7 Gton C/yr that mankind is releasing to the atmosphere today, 4 Gton C/yr is going away as quickly as we release it. This leads to a simple but powerful conclusion: if we want atmospheric CO2 to stop going up, tomorrow, we have to reduce our CO2 emissions from 7 Gton C/yr down to 4 Gton C/yr, say a reduction of total carbon emission by 40%. Then the CO2 concentration in the atmosphere would stop rising, but remain at its current level of 365 ppm. This could continue until the terrestrial biosphere and the ocean equilibrated at this new level, "filled up" with the new higher CO2. No one has any idea how long it would take for the terrestrial biosphere to saturate or fill up, but the ocean would take several centuries. If emissions were stopped after that, the atmospheric CO2 concentration would remain at 365 ppm for thousands of years.
- David Archer, Understanding the Forecast
Using microwave observations to assess large-scale control of free tropospheric water vapor in the mid-latitudes.
Radiative impacts of atmospheric methane and CO2 concentrations.
Iceberg research station being installed on the Ross Ice Shelf's nascent iceberg in order to study how Earth's ice sheets respond to warming temperatures.
Human diet has a profound influence on the release of greenhouse gasses (CO2) into the atmosphere. A red meat diet is has the most per capita impact on the atmospheric load of greenhouse gasses.
The study of Earth and planetary climates occupies a long-standing research interest in the department. Since the founding of the University of Chicago, faculty and students have been engaged in developing an understanding of Earth's past climates. Some of the seminal research on ice-age climate cycles was done during the first half of the 20th century at the University, for example.
Research into past, present and future climate has been pursued with greater vigor now that it is apparent that humankind has become an agent of climate change. It is now widely recognized that changes in the global environment are occuring at rates which greatly exceed those which have occured in the geologic past. For example, atmospheric concentrations of greenhouse gases such as carbon dioxide and methane are steadily rising, stratospheric ozone depletion is occuring in both polar regions (the Ozone hole) and at midlatitudes, and there is now evidence for widespread pollution of the lower atmosphere. The potantial effects of these changes on the global climate system and biosphere make this field of global change science one of the most vibrant and exciting disciplines within earth science.
By its nature, the field is highly interdisciplinary. In particular, in order to fully understand the coupled nature of the earth-atmosphere-biosphere system requires that aspects of geophysical fluid dynamics, oceanic and atmospheric chemistry, cloud physics and radiative properties, and glaciology be well understood.
Current Research
Current topics of research in the department involve the effort to understand origin and the influence of radiatively active trace gasses (i.e., the greenhouse gasses) in the atmospheres of Earth and Mars. Research on the ocean's carbon budget, for example, gives insight into the timescales associated with the fate of anthropogenic CO2 in the atmosphere. Research on surface melting of the Greenland Ice Sheet, for example, gives insight into the likely impact of global warming over the next century.
Faculty:
• David Archer, Chemical Oceanography• Bruce Buffett, Geodynamics
• Albert Colman
• John E. Frederick, Radiative Transfer
• Douglas R. MacAyeal, Glaciology
• Pamela Martin, Paleoceanography
• Elisabeth J. Moyer, Atmospheric Chemistry
• Noboru Nakamura, Atmospheric Dynamics
• Raymond T. Pierrehumbert, Atmospheric Dynamics
• Ramesh C. Srivastava, Cloud Physics
Research Scientists:
• Jeremy Bassis
• Robert Jacob
Research Centers in Climate Dynamics
The Fast Ocean Atmosphere Model Development Group
