WASHINGTON (AP) — The world sweltered with continued signs
of climate change in 2012, according to a new U.S. study.
Rising sea levels, snow melt, heat buildup in the oceans and
melting Arctic sea ice and Greenland ice sheets all broke or nearly broke
records, but temperatures only sneaked into the top 10.
The National Oceanic and Atmospheric Administration recently
issued a peer-reviewed, 260-page report which agency chief Kathryn Sullivan
calls its annual “checking on the pulse of the planet.” The report, written by
384 scientists around the world, compiles data already released, but it puts
them in context of what’s been happening to Earth over decades.
“It’s critically important to compile a big picture,” said
Tom Karl, National Climatic Data Center director. “The signs that we see are of
a warming world.”
Sullivan said that what is noticeable “are remarkable
changes in key climate indicators,” mentioning dramatic spikes in ocean heat
content, a record melt of Arctic sea ice in the summer and whopping temporary
melts of ice in most of Greenland last year. The data also shows a record-high
The most noticeable and startling changes seen were in the
Arctic, said report co-editor Deke Arndt, climate monitoring chief at the data
Breaking records in the Arctic is so common that it is
becoming the new normal, added study co-author Jackie Richter-Menge of the U. S.
Army Corps of Engineers’ Cold Regions Research and Engineering Laboratory.
Karl said that when looked at together, all the indicators
show a climate that is changing over the decades. Individually, however, the
story isn’t as simple.
Karl said surface temperatures haven’t risen in the last 10
years, but he noted that is only a blip in time due to natural variability.
When looking at more scientifically meaningful time frames
of 30 years, 50 years and more than 100 years, temperatures are rising quite a
bit, Karl said. Since records have been kept in 1880, all 10 of the warmest
years ever have been in the past 15 years, NOAA records show.
Depending on which of four independent analyses are used,
2012 ranked the eighth or ninth warmest year on record, the report said.
Last year was warmer than every year in the previous
century, except for 1998 when a record El Nino spiked temperatures globally.
NOAA ranks 2010 as the warmest year on record.
They don’t have to be records every year, Karl said.
Overall, the climate indicators “are all singing the same
song that we live in a warming world,” Arndt said. “Some indicators take a few
years off from their increase. The system is telling us in more than one place
we’re seeing rapid change.”
While the report purposely doesn’t address why the world is
warming, “the causes are primarily greenhouse gases, the burning of fossil
fuels,” Arndt said.
The study is being published in a special edition of the
Bulletin of the American Meteorological Society.
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