New evidence for global warming

摘要

Since 1979, average temperature measurements taken at Earth's surface have shown a warming trend for the planet of 0.13℃ per decade, a figure in line with most global climate models. But satellite data for the lowest level of the troposphere (at about 3.5 km) have shown a cooling trend of 0.05℃ per decade. Now, findings by Frank J. Wentz and Matthias Schabel of Remote Sensing Systems in Santa Rosa, Calif., show that the apparent cooling trend in the lower troposphere is an artifact caused by previously neglected orbital decay effects on the satellites [Nature, 394, 661 (1998)]. When they take orbital decay into account, they find that the lower troposphere has warmed 0.07℃ per decade.