Purporting to correct comments made by Al Gore about the impact of global warming on the North polar ice cap, both Fox News' Glenn Beck and Andrew Breitbart's Breitbart.tv forwarded the false suggestion that, in the past two years, Arctic ice “has returned” and “is increasing.” In fact, 2008 and 2009 were the second and third lowest years on record for summertime Arctic sea ice and the National Snow and Ice Data Center (NSIDC) has stated that the data from the past two years are consistent with the long-term negative trend that will result in ice-free summers for the Arctic Ocean.
Attempting to correct Gore, Beck, Breitbart claim Arctic ice is increasing in size
Breitbart.tv: “Gore says arctic ice is disappearing while the scientific proof is that arctic ice is increasing.” A video posted on Breitbart.tv on December 14 asserted of Arctic sea ice: "[T]he minimum in 2008 was 700,000 square kilometers more than in 2007, and the minimum this year, which was reached earlier than normal on 12 September, 2009, (meaning it got cold earlier and arctic ice began increasing sooner) ... was 1 MILLION SQUARE KILOMETERS MORE THAN IN 2007, AND 300,000 SQUARE KILOMETERS MORE THAN IN 2008!!! Al Gore says arctic ice is disappearing while the scientific proof is that arctic ice is increasing."
Beck: "[N]early all of the ice has returned." Purporting to correct Gore's “lies,” Beck stated on his Fox News program, “In September of 2007, there was a 25 percent reduction in the usual minimum ice cover. This, my friend, is the truth: 25 percent. In the two years since, nearly all of the ice has returned. He must have some wrong and old data.”
NSIDC: 2007 low-point was 39 percent lower than long-term average. Contrary to Beck's claim that "[i]n September of 2007, there was a 25 percent reduction in the usual minimum ice cover," and that "[i]n the two years since, nearly all of the ice has returned," NSIDC stated that "[a]t the end of the melt season, September 2007 sea ice was 39 percent below the long-term average from 1979 to 2000." In 2008, the minimum sea ice extent was 33 percent below the long-term average. And in 2009, the minimum sea ice extent was 24 percent below the long-term average.
AP: Melting in 2008 and 2009 “ranked as the second- and third-greatest decreases on record.” The Associated Press reported on December 14 that "[i]n the summer of 2007, the Arctic ice cap dwindled to a record-low minimum extent of 4.3 million square kilometers (1.7 million square miles) in September. The melting in 2008 and 2009 was not as extensive, but still ranked as the second- and third-greatest decreases on record."
NSIDC director: "[T]here's no reason to think that we're headed back to conditions seen back in the 1970s." NSIDC director and senior scientist Mike Serreze stated of the 2009 ice data: “It's nice to see a little recovery over the past couple years, but there's no reason to think that we're headed back to conditions seen back in the 1970s. We still expect to see ice-free summers sometime in the next few decades.” NSIDC lead scientist Ted Scambos also said: “A lot of people are going to look at that graph of ice extent and think that we've turned the corner on climate change. But the underlying conditions are still very worrisome.” On September 17, NSIDC reported the 2009 minimum Arctic sea ice extent and stated, “While this year's minimum extent is above the record and near-record minimums of the last two years, it further reinforces the strong negative trend in summertime ice extent observed over the past thirty years.” According to NSIDC: "[I]ce extent has shown a dramatic overall decline over the past thirty years. During this time, ice extent has declined at a rate of 11.2 percent per decade during September (relative to the 1979 to 2000 average)."
From an October 6 NSDIC analysis:
NASA: Arctic sea ice “thinned dramatically” between 2004 and 2008. In July, scientists from NASA and the University of Washington in Seattle concluded that, based on a comprehensive survey of satellite data, “overall Arctic sea ice thinned about 0.17 meters (7 inches) a year, for a total of 0.68 meters (2.2 feet) over four winters. The total area covered by the thicker, older 'multi-year' ice that has survived one or more summers shrank by 42 percent.” NASA further stated, “In recent years, the amount of ice replaced in the winter has not been sufficient to offset summer ice losses. The result is more open water in summer, which then absorbs more heat, warming the ocean and further melting the ice. Between 2004 and 2008, multi-year ice cover shrank 1.54 million square kilometers (595,000 square miles) -- nearly the size of Alaska's land area.”
Submarine data also show trend of sea ice thinning. On October 19, the National Oceanographic and Atmospheric Administration (NOAA) stated, “The recent satellite estimates were compared with the longer historical record of declassified sonar measurements from US Navy submarines (Figure S4b). Within the submarine data release area (covering ~38% of the Arctic Ocean), the overall mean winter thickness of 3.6 m in 1980 can be compared to a 1.9 m mean during the last winter of the ICESat record -- a decrease of 1.7 m in thickness. This combined submarine and satellite record shows a long-term trend of sea ice thinning over submarine and ICESat records that span three decades.”
BBC: “Young, thin ice” worries scientists. On September 17, BBC reported that "[w]hat continues to have scientists worried is that a significant proportion of the cover consists of young, thin ice formed in a single winter. This is much more prone to melting than the older, thicker ice that dominated in years gone by." Indeed, in its October 6 analysis, NSIDC stated of the Arctic sea ice in 2009:
The ice cover remained thin, leaving the ice cover vulnerable to melt in coming summers. Scientists use satellites to measure ice age, a proxy for ice thickness. This year, younger (less than one year old), thinner ice, which is more vulnerable to melt, accounted for 49 percent of the ice cover at the end of summer. Second-year ice made up 32 percent, compared to 21 percent in 2007 and 9 percent in 2008 (Figure 5). Only 19 percent of the ice cover was over 2 years old, the least in the satellite record and far below the 1981-2000 average of 52 percent. Earlier this summer, NASA researcher Ron Kwok and colleagues from the University of Washington in Seattle published satellite data showing that ice thickness declined by 0.68 meters (2.2 feet) between 2004 and 2008.
NSIDC Scientist Walt Meier said, “We've preserved a fair amount of first-year ice and second-year ice after this summer compared to the past couple of years. If this ice remains in the Arctic through the winter, it will thicken, which gives some hope of stabilizing the ice cover over the next few years. However, the ice is still much younger and thinner than it was in the 1980s, leaving it vulnerable to melt during the summer.”
Meier: “Most people would agree it is not a matter of if we lose the summer sea ice but when.” The Telegraph reported on April 7 that Walt Meier, research scientist at NSIDC, “said thinner sea ice is less likely to survive the summer and predicted the Arctic Ocean will be effectively ice free sometime between 2020 and 2040, although it is possible it could happen as early as 2013.” Meier further stated: “Most people would agree it is not a matter of if we lose the summer sea ice but when. ... Temperatures are still warming because of carbon dioxide in the atmosphere and the greenhouse effect. Even if we stopped that temperatures will continue rising and we will see 'positive feedback' where the ocean absorbs more energy therefore increasing the melting effect.” Predictions of when the Arctic sea will have an ice-free summer vary from "less than 10 years" to several decades into the future. On October 15, National Geographic reported that NSIDC's Mark Serreze said of the widely varying predictions, “When we lose the ice really depends on the natural variability in the system” :
Dueling Dates for Arctic Ice Melt
The new data, presented by the Catlin Arctic Survey and the international conservation group WWF, support the view that the Arctic will be ice free in the summer within about 20 years.
Most of the ice melt is expected to happen within the next ten years, [sea-ice expert Peter] Wadhams said in his statement.
Serreze's group in Boulder, though, is on record saying the Arctic's summer sea ice will fully melt around 2030. Other groups have put the ice-free date as late as 2100.
Why such seemingly wild guesses?
“When we lose the ice really depends on the natural variability in the system,” Serreze said.
A good example of this is the record low year of 2007. That summer saw a perfect storm of climatic conditions: warm temperatures plus wind patterns that broke apart and pushed large chunks of ice out of the Arctic.
The summers of 2008 and 2009 have seen some recovery of Arctic ice, though the long-term trend is still for shrinking ice, Serreze said.
Will the slow, steady trend be the norm? Or will another year like 2007 come along and wipe out the Arctic ice?
“These are the unknowns,” Serreze said. “We simply don't know.”