Unstoppable Global Warming: Every 1,500 Years
Recorded on March 13, 2007
Location: The Heritage Foundation's Lehrman Auditorium
The Earth currently is experiencing a warming trend, but there
is scientific evidence that this warming seems to be part of a
1,500-year cycle (plus or minus 500 years) of moderate temperature
swings. It has long been accepted that the Earth has
experienced climate cycles, most notably the 90,000-year Ice Age
cycles. But in the past 20 years or so, modern science has
discovered evidence that within those broad Ice Age cycles, the
Earth also experiences 1,500-year warming-cooling cycles.
Evidence of the global nature of the 1,500-year climate cycles
includes very long-term proxies for temperature change - ice cores,
seabed and lake sediments, and fossils of pollen grains and tiny
sea creatures. Shorter-term proxies include cave stalagmites,
tree rings from trees both living and buried, boreholes and a wide
variety of other temperature proxies.
So, is the Earth currently experiencing a warming trend?
Yes. Are human activities, including the burning of fossil
fuel and forest conversion, the primary - or even significant -
drivers of this current temperature trend? The scientifically
appropriate answer - cautious and conforming to the known facts -
is: probably not.
S. Fred Singer, an Adjunct Scholar with the National Center
for Policy Analysis, is Professor Emeritus of Environmental Science
at the University of Virginia, and President of the Science and
Environmental Policy Project. He was the first Director of
the U.S. Weather Satellite Service and served five years as Vice
Chairman of the National Advisory Committee on Oceans and
Atmospheres. He received the first Science Medal from the
British Interplanetary Society and won a NASA commendation in 1997
for his research on particle clouds.