A “radical shift” is plunging the Arctic Ocean towards an ice-free state for the first time in millions of years. One of the world’s foremost ice experts, Professor Peter Wadhams of Cambridge University, calls it a “global disaster” that will cause such a big boost in global temperatures that even such extreme measures as geo-engineering need to be considered urgently.
Climate science has long understood that disappearance of summer sea ice in the Arctic would be a “tipping point” in the Earth’s climate system, accelerating global temperatures and causing extreme weather and other climate changes far beyond the Arctic. Yet nearly every expert has been shocked by just how rapidly this “continent of ice” has been vanishing, and how dramatic the impacts have been already.
Climate scientists and ice experts are now using phrases like “unprecedented”, “amazing”, “extreme”, “hard to exaggerate”, “incredibly fast”, “death spiral” and “heading for oblivion”.
As the Republican Party denies, denies, denies that global warming is real: Canada’s Arctic ice shelves breaking up fast.
Luke Copland, an associate geography professor at the University of Ottawa, said the Serson Ice Shelf shrank from 79 square miles to two remnant sections five years ago, and was further diminished this past summer.
Serson went from a 16-square-mile floating glacier tongue to 10 square miles, and the second section from 13 square miles to 2 square miles.
In addition, Ward Hunt Ice Shelf’s central area disintegrated into drifting ice masses last summer, leaving two separate ice shelves measuring 88 and 29 square miles respectively, reduced from 132 square miles the previous year.
“It has dramatically broken apart in two separate areas and there’s nothing in between now but water,” said Copland.
Copland said those two losses are significant, especially since the Ward Hunt Ice Shelf has always been the biggest, the farthest north and the one scientists thought might have been the most stable.
“Since the end of July, pieces equaling one and a half times the size of Manhattan Island have broken off,” Copland said in a statement. Copland uses satellite imagery and has conducted field work in the Arctic every May for the past five years.
Co-researcher Derek Mueller, an assistant professor at Carleton University, said the loss this past summer equals up to three billion tons of ice.
“This is our coastline changing,” Mueller stated. “These unique and massive geographical features that we consider to be part of the map of Canada are disappearing and they won’t come back.”
“Recent (ice shelf) loss has been very rapid, and goes hand-in-hand with the rapid sea ice decline we have seen in this decade and the increasing warmth and extensive melt in the Arctic regions,” said Ted Scambos, lead scientist at the National Snow and Ice Data Center at the University of Colorado, remarking on the research.
A disturbing report at the National Snow and Ice Data Center shows that the rate of decline in sea ice extent for the month of May 2010 was the fastest in the satellite record.
Credit: National Snow and Ice Data Center
In May, Arctic air temperatures remained above average, and sea ice extent declined at a rapid pace. At the end of the month, extent fell near the level recorded in 2006, the lowest in the satellite record for the end of May. Analysis from scientists at the University of Washington suggests that ice volume has continued to decline compared to recent years. However, it is too soon to say whether Arctic ice extent will reach another record low this summer—that will depend on the weather and wind conditions over the next few months. …
Average ice extent for May 2010 was 480,000 square kilometers (185,000 square miles) greater than the record low for May, observed in 2006, and 500,000 square kilometers (193,000 square miles) below the average extent for the month. The linear rate of decline for May over the 1979 to 2010 period is now -2.41% per decade.
The rate of decline through the month of May was the fastest in the satellite record; the previous year with the fastest daily rate of decline in May was 1980. By the end of the month, extent fell near the level recorded in 2006, the lowest in the satellite record for the end of May. Despite the rapid decline through May, average ice extent for the month was only the ninth lowest in the satellite record.
(Hat tip: freetoken.)
Twenty-six climatologists from around the world have released a new report in advance of the Copenhagen climate summit titled The Copenhagen Diagnosis, with startling findings based on the latest peer-reviewed research, suggesting that sea levels are rising much faster than even the IPCC has projected.
The executive summary of the report is more than a little alarming:
Surging greenhouse gas emissions: Global carbon dioxide emissions from fossil fuels in 2008 were nearly 40% higher than those in 1990. Even if global emission rates are stabilized at present –day levels, just 20 more years of emissions would give a 25% probability that warming exceeds 2oC. Even with zero emissions after 2030. Every year of delayed action increase the chances of exceeding 2oC warming.
Recent global temperatures demonstrate human-based warming: Over the past 25 years temperatures have increased at a rate of 0.190C per decade, in every good agreement with predictions based on greenhouse gas increases. Even over the past ten years, despite a decrease in solar forcing, the trend continues to be one of warming. Natural, short- term fluctuations are occurring as usual but there have been no significant changes in the underlying warming trend.
Acceleration of melting of ice-sheets, glaciers and ice-caps: A wide array of satellite and ice measurements now demonstrate beyond doubt that both the Greenland and Antarctic ice-sheets are losing mass at an increasing rate. Melting of glaciers and ice-caps in other parts of the world has also accelerated since 1990.
Rapid Arctic sea-ice decline: Summer-time melting of Arctic sea-ice has accelerated far beyond the expectations of climate models. This area of sea-ice melt during 2007-2009 was about 40% greater than the average prediction from IPCC AR4 climate models.
Current sea-level rise underestimates: Satellites show great global average sea-level rise (3.4 mm/yr over the past 15 years) to be 80% above past IPCC predictions. This acceleration in sea-level rise is consistent with a doubling in contribution from melting of glaciers, ice caps and the Greenland and West-Antarctic ice-sheets.
Sea-level prediction revised: By 2100, global sea-level is likely to rise at least twice as much as projected by Working Group 1 of the IPCC AR4, for unmitigated emissions it may well exceed 1 meter. The upper limit has been estimated as – 2 meters sea-level rise by 2100. Sea-level will continue to rise for centuries after global temperature have been stabilized and several meters of sea level rise must be expected over the next few centuries.
Delay in action risks irreversible damage: Several vulnerable elements in the climate system (e.g. continental ice-sheets. Amazon rainforest, West African monsoon and others) could be pushed towards abrupt or irreversible change if warming continues in a business-as-usual way throughout this century. The risk of transgressing critical thresholds (“tipping points”) increase strongly with ongoing climate change. Thus waiting for higher levels of scientific certainty could mean that some tipping points will be crossed before they are recognized.
The turning point must come soon: If global warming is to be limited to a maximum of 2oC above pre-industrial values, global emissions need to peak between 2015 and 2020 and then decline rapidly. To stabilize climate, a decarbonized global society – with near-zero emissions of CO2 and other long-lived greenhouse gases – need to be reached well within this century. More specifically, the average annual per-capita emissions will have to shrink to well under 1 metric ton CO2 by 2050. This is 80-90% below the per-capita emissions in developed nations in 2000.