Climate Change Record in Subsurface Temperatures: A Global Perspective
Henry N. Pollack,
*
Shaopeng Huang,
Po-Yu Shen
Analyses of underground temperature measurements from 358 boreholes
in eastern North America, central Europe, southern Africa, and
Australia indicate that, in the 20th century, the average surface
temperature of Earth has increased by about 0.5°C and that the 20th
century has been the warmest of the past five centuries. The subsurface
temperatures also indicate that Earth's mean surface temperature has
increased by about 1.0°C over the past five centuries. The geothermal
data offer an independent confirmation of the unusual character of
20th-century climate that has emerged from recent multiproxy studies.
H. N. Pollack and S. Huang, Department of Geological
Sciences, University of Michigan, Ann Arbor, MI 48109-1063, USA.
P.-Y. Shen, Department of Earth Sciences, University of Western
Ontario, London, Ontario N6A 5B7, Canada.
*
To whom correspondence should be addressed.