One of the arguments climate change deniers use is the belief global temperatures the warming of the planet’s surface slowed at the turn of the century. A new study released by the National Oceanic and Atmospheric Administration throws a big spanner into that argument.
The new report states that Earth’s global average surface temperature had climbed 0.2 of a degree Fahrenheit each decade since 1950, without interruption, due to the heat-trapping effects of greenhouse gases. Researchers based their measurements on from thousands of land stations, ships and buoys at sea going back to 1880.
The report has been received mixed reception; “It’s always good to go back and look at the data as carefully as possible and make sure it’s calibrated correctly,” said William Patzert, a climatologist at NASA’s Jet Propulsion Laboratory in La Cañada Flintridge. “But the hiatus is history and it was real.”
The NOAA stands by its results; the researchers argue that long-standing problems with the way temperatures are measured have masked years of sea surface warming. Once those problems are corrected for, “this hiatus or slowdown simply vanishes,” said lead study author Thomas Karl, director of NOAA’s National Climatic Data Center.
Karl said he had been challenged frequently by fellow scientists but stood by the study’s conclusion. He said he was often asked whether he was denying the cooling effects of volcanic aerosols, a cyclical dip in solar energy or the heat-absorbing effects of the ocean.
“All of those factors are real,” Karl said. “If those factors had not occurred, the warming rate would have been even greater. … If anything we may still be underestimating the trend.”
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