Nasa satellite data was presented today in San Francisco at the American Geophysical Union conference showing that up to two trillion tons of land ice has melted away since 2003.
Primarily impacted are Alaska, Antarctica, the Arctic, and Greenland, which lost almost half of the total ice melt measured by NASA's Gravity Recovery and Climate Experiment (GRACE).
The ice tells us in a very real way how the climate is changing," said NASA geophysicist Scott Luthcke.
Luthcke's data concurs with NASA colleague Jay Zwally's research using different satellite technology that observes changing ice volume in Greenland, the Arctic, and Antarctica.
Zwally will present research at the American Geophysical Conference that shows in the past five years Greenland has lost between 150 and 160 gigatons of ice each year, enough to raise sea levels about .5mm annually.
In the 1990's, says Zwally, Greenland took in about as much snow and ice as it let out. Now, fifteen years later, sea levels are rising 50% faster.
The best estimates are that sea levels will rise about 18 to 36 inches by the end of the century, but because of what's going on and how fast things are changing, there's a lot of uncertainty," he said.
The accelerating ice loss leads to further warming as the diminishing reflective ice exposes more land and ocean surface that absorbs more heat, a principle aspect of the phenomenon known as "Arctic Amplification" .
We may be going through a tipping point [in climate change] right now." Zwally says, "Once the ice goes away, you're absorbing much more heat." The Arctic is showing two to three times the overall global rate of temperature increase.
Scientists at the National Snow and Ice Data Center in Colorado say that autumn temperatures in some Arctic locations this year were 9 to 10 degrees Fahrenheit higher than average.
Deniers: "Temperatures Are Cooling - Global Warming Ended in 1998"
That's the latest, most common meme from the denialist camp. Fueled, apparently, by the El Niño in 1998 (making it markedly warmer than average), a lack of understanding of running averages, and ignoring everything that has happened since then. The first decade of the 21st century will likely be 0.2º warmer than the 1990's. The 1990's were only 0.14º on average warmer than the 1980's, so the warming is increasing and the running average is up.
Yesterday the Hadley Meteorological Center and the World Meteorological Organization reported that 2008 will be the 10th warmest year on record - in spite of the cooling effects of La Niña. The ten warmest years on record have occurred since 1997.
For those deniers that are insistent on pushing their misinformation, Joseph Romm, editor of ClimateProgress.org and Senior Fellow at the Center for American Progress has offered a bet (at 2:1 odds) of $1000 that the decade from 2010 to 2019 will be warmer that the decade from 2000 to 2009. So if you insist, here's your chance to quit your bellyaching and put your money where your mouth is.
The rest of us are ready to get to work creating a sustainable future.
Chart courtesy the Hadley Center
Chart courtesy ClimateProgress.org