Whether you're concerned about Earth's environment or the likelihood of
another booby showing up on Protection Island, here's pertinent
information, just forwarded by Bill Tweit. Isn't this instantaneous flow of
information fantastic? Anyone feel overloaded yet?

> URL: http://www.eurekalert.org/releases/um-ewsflh.html
> Title: Study Shows Earth Warming Since 1500, Most In Last 100 Years
> ----------------------------------------------
> >>> Embargoed For Release: 10 December 1997 at 18:00:00 ET US
> >>>
> >>> Contact: Sally Pobojewski
> >>> pobo at umich.edu
> >>> (313) 647-1844
> >>> University of Michigan
> >>>
> >>> Study Shows Earth Warming Since 1500, Most In Last 100 Years
> >>>
> >>> SAN FRANCISCO---A new 300-site survey of borehole temperatures spanning
> >>> four continents and five centuries has confirmed what most scientists
> >>> already believe---the Earth is getting warmer and the rate of warming has
> >>> been accelerating rapidly since 1900.
> >>>
> >>> "In terms of climate change, the 20th century has not been just another
> >>> century," said Henry N. Pollack, University of Michigan professor of
> >>> geological sciences. "Subsurface rock temperatures confirm that the
> >>> average global surface temperature has increased about 1 degree C. (1.8
> >>> degrees F.) over the last five centuries with one-half of that warming
> >>> taking place in the last 100 years. The 20th century is the warmest and
> >>> has experienced the fastest rate of warming of any of the five centuries
> >>> in our study."
> >>>
> >>> Pollack presented temperature readings from 300 underground boreholes in
> >>> Europe, North America, Australia and South Africa at the American
> >>> Geophysical Union meeting held here this week.
> >>>
> >>> Pollack is one of several geologists who take the Earth's temperature by
> >>> lowering sensitive thermometers into boreholes drilled from the surface.
> >>> Because subsurface rocks preserve a record of actual surface temperature
> >>> changes over time, boreholes are an important data source for scientists
> >>> studying global climate change. Short-term changes, such as seasonal
> >>> variations, penetrate only a few meters underground. Long-term changes on
> >>> scales of hundreds of years are preserved at greater depths. Since
> >>> meteorological data has been recorded globally only for the last 100 years
> >>> or so, borehole temperatures are especially important in determining
> >>> surface temperature for previous centuries.
> >>>
> >>> Individual borehole temperatures can be skewed by local topography or
> >>> climate conditions, so Pollack and Shaopeng Huang, U-M assistant research
> >>> scientist, merged the readings into continental data ensembles to balance
> >>> out local effects and let regional trends come through. They then combined
> >>> all four regions to get a global average. Because meteorologists track
> >>> long-term climate changes in 100-year intervals, Pollack and Huang also
> >>> looked for century-long trends in borehole data.
> >>>
> >>> When they compared the average worldwide borehole temperature change with
> >>> global meteorological records over the last century, they found both
> >>> recorded a 0.5 degree C. average global temperature increase since 1900.
> >>> "The ground says the same thing the air says," Pollack explained.
> >>>
> >>> According to Pollack, 80 percent of the total 1 degree C. warming recorded
> >>> in borehole readings from 1500 to the present occurred after 1750 when
> >>> people began large-scale burning of coal, wood and other fossil fuels
> >>> during the Industrial Revolution. Since most warming has taken place after
> >>> 1750, Pollack believes it is likely a direct result of human activity,
> >>> rather than a natural climate fluctuation.
> >>>
> >>> "If the upward trend of greenhouse gas emissions continues, we can expect
> >>> another 1 degree C. increase in average global temperature by 2050,"
> >>> Pollack said. "This estimate is not based on model computations, but a
> >>> projection of actual data. Our results agree with the estimates of global
> >>> climate warming issued by the United Nations' Intergovernmental Panel on
> >>> Climate Change (IPCC) and are fully consistent with the conclusion of the
> >>> IPCC's scientific panel that human activity is a significant driving force
> >>> behind global warming."
> >>>
> >>> Pollack's study has been funded by the National Science Foundation and the
> >>> Czech-USA Cooperative Science Program.

Dennis Paulson, Director phone 253-756-3798
Slater Museum of Natural History fax 253-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416
http://www.ups.edu/biology/museum/museum.html