From the Tropics to the Arctic, graphics tell the tale of global warming’s impact in 2010
As I’ve reported over the past few days, the global average temperature from January through August was the hottest in 131 years of record keeping. Satellite measurements of the temperature of the atmosphere show a similar picture.
Now, the global environment seems to be noticing.
In the tropical and sub-tropical oceans, for example, coral reefs are in trouble…
High ocean temperatures in many regions of the world have increased the potential for coral bleaching, in which corals lose the symbiotic algae responsible for their vibrant, distinctive colors. When bleaching becomes severe enough the corals are at high risk of dying. In the map above, “Alert Level 2″ indicates areas where the potential for bleaching is so high between now and December that mass coral mortality is a major risk.
The Caribbean and Gulf of Mexico are of particular concern. From the National Oceanic and Atmospheric Administration’s Coral Reef Watch:
. . . sea surface temperatures (SSTs) continue to remain above average throughout the wider Caribbean region. Large areas of the southeastern Caribbean Sea are experiencing thermal stress capable of causing coral bleaching. The western Gulf of Mexico and the southern portion of the Bahamas have also experienced significant bleaching thermal stress. The CRW Coral Bleaching Thermal Stress Outlook . . . indicates that the high stress should continue to develop in the southern and southeast Caribbean until mid-October. Bleaching stress in the western Gulf of Mexico and southern Bahamas should dissipate quickly in the next couple of weeks.
And in the Arctic, sea ice continues to disappear . . .
The National Snow and Ice Data Center officially announced today that with summer on the wane, Arctic sea ice appears to have reached its minimum extent, as the little uptick in the blue line in the graph above suggests. The 2010 minimum is the third-lowest recorded since 1979, according to NSIDC.
Perhaps an even better indication of the deteriorating condition of Arctic sea ice is its volume, as opposed to its simple geographic extent. That’s more difficult to determine.
Scientists at the University of Washington use a model, called the Pan-Arctic Ice Ocean Modeling and Assimilation System, or PIOMAS, to calculate Arctic Sea Ice Volume. PIOMAS incorporates observations of winds, temperature, sea ice concentration and other factors into its calculations. And the model is validated by comparing its output with observations from instruments on moorings and satellites, as well as by U.S. Navy submarines. And so far, the model seems to have stood up fairly well compared to reality.
This year, according to the PIOMAS model, Arctic sea ice volume reached a record low, as the graph above shows. According to the University of Washington’s Ron Lindsay, quoted in Science today, ice volume has decreased by about 17 percent per decade and is now almost 10,000 cubic kilometers less than the 30- year average.