Computer models by Hansen and others suggest that by the middle of the next century, Earth’s average temperature may rise 4 to 9 degrees Fahrenheit, possibly altering storm patterns, triggering droughts, making crops fail and raising sea levels to flood low-lying coastal areas.
Analysis of warming since 1881 shows most of the increase in global temperature happened before 1919 — before the more recent sharp rise in the amount of carbon dioxide in the atmosphere, said Thomas Karl, of the National Oceanic and Atmospheric Administration’s Climatec Data Center in Asheville, N.C.
While global climate warmed overall since 1881, it actually cooled from 1921 to 1979, Karl said.
“In spite of all the well-publicized concern about global warming, you must understand that there is still considerable uncertainty among scientific experts about a number of critical factors which determine global warming,” NOAA administrator John Knauss said in a statement issued for the geophysics meeting.
Source: Santa Cruz Sentinel