National Oceanic and Atmospheric Administration climate study puts 2012 among the 10 warmest years on record
Last year was among the 10 warmest years on record – ranking eighth or ninth depending on the data set, according to a report led by the National Oceanic and Atmospheric Administration (Noaa). The year 2012 also saw record greenhouse gas emissions, with concentrations of carbon dioxide and other warming gasses reaching a global average of 392.7 parts per million for the year.
"The findings are striking," Kathryn Sullivan, Noaa’s acting administrator, said on a conference call. "Our planet as a whole is becoming a warmer place."
The scientists were reluctant to point directly to the cause of the striking changes in the climate. But the annual reports are typically used by the federal government to prepare for the future, and in June president Barack Obama used his climate address to direct government agencies to begin planning for decades of warming atmosphere and rising seas.
The biggest changes in the climate in 2012 were in the Arctic and in Greenland, said the report, which is an annual exercise by a team of American and British scientists. The Arctic warmed at about twice the rate of lower latitudes, the report found. By June 2012, snow cover had fallen to its lowest levels since the record began. By September 2012, sea-ice cover had retreated to its lowest levels since the beginning of satellite records, falling to 1.32 million square miles.
Water from the world’s shrinking glaciers was responsible for almost a third of the rise in sea levels between 2003 and 2009, shows new research.
An international team of scientist compared data gleaned from two NASA satellites as well as traditional ground measurements from glaciers around the world.
Their work, published in the journal Science , is the most accurate estimation of how glaciers contribute to sea level rises to date.
"For the first time, we’ve been able to very precisely constrain how much these glaciers as a whole are contributing to sea rise," says lead author Assistant Professor Alex Gardner, assistant geography professor at Clark University in Worcester, Massachusetts.
"These smaller ice bodies are currently losing about as much mass as the ice sheets."
The most significant ice losses occurred in Arctic Canada, Alaska, coastal Greenland, the southern Andes and the Himalayas, the study found.
The glaciers outside of the Greenland and Antarctic sheets lost an average of roughly 260 billion metric tons of ice annually during the period, leading to a rise in ocean levels of about 0.7 millimeters per year.
By contrast the glaciers in Antarctica, smaller ice masses that are not connected to the ice sheet, made scarcely any contribution to sea-level rise over the study period.
Note that sea level rise is uneven, and effects coastlines with high degrees of variability. Some coast will experience more rise and erosion, some less.
I’m so surprised by the depth of research and overall usefulness of the How Stuff Works website. This post on the North Pole covers how to prepare for an Arctic Expedition. It included this nice nugget:
From the 15th through the 20th century, the Doctrine of Discovery was recognized by European and American explorers as the go-to guideline for ownership of territory. The doctrine uses a basic “first-come, first-served” rule — a region belongs to whatever country got there first. Remember how the United States “won” the race to the moon in 1969 by planting a flag on the lunar surface?
Today, the United Nations has taken control of the issue. According to the U.N. Convention on the Laws of the Sea, claims to the North Pole are based on a country’s continental shelf (undersea extensions of land).
In 2007, Russian mini-submarines — on a mission to explore natural gas and oil deposits under the North Pole — planted Russian flags below the Arctic ice. The Canadians were not pleased, mostly because they claim that the North Pole is theirs. So do Denmark (via Greenland), Norway and the United States.