2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 6
Presentation Time: 11:00 AM

EXAGGERATION OF HUMAN-INDUCED GLOBAL WARMING PREDICATIONS


GRAY, William M., Atmospheric Science, Colorado State University, Fort Collins, CO 80523, gray@atmos.colostate.edu

The role of anthropogenic CO2 as a causal mechanism of the observed global warming over the past 30 years and last century has been exaggerated. Most of this warming is due to natural climatic cycles driven by changes in the mean rate of the ocean's meridional overturning circulation (MOC). The numerical GCM simulations of the influence of human-induced greenhouse gases are flawed due to their inability to realistically model upper-level water vapor. Most GCM's are programmed to cause increases in upper-level water vapor as global precipitation increases. However, observations over the last 40-50 years indicate that there has been a small decrease in upper-level water vapor associated with increased precipitation and global warming. Evidence will be presented to show that global atmospheric temperature warming over the last 30 years (and the last century) is primarily due to natural changes in salinity-driven deep ocean circulation. Atmospheric and oceanic proxies for the mean rate of meridional ocean circulation (MOC) will be presented that link variations in the mean rate of MOC (with a multi-year lag) to periods of global warming and cooling.

A discussion of the Atlantic and global variations of tropical cyclone activities over the last 50 years will also be presented. Evidence does not support an anthropogenic component.