|Are the ice caps melting?
Climate science's bipolar disorder
Register | July 3, 2008
The headlines last week brought us terrifying news: The North Pole will be ice-free this summer "for the first time in human history," wrote Steve Connor in The Independent. Or so the experts at the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado predict. This sounds very frightening, so let's look at the facts about polar sea ice.
As usual, there are a couple of huge problems with the reports.
Firstly, the story is neither alarming nor unique.
In the August 29, 2000 edition of the New York Times, the same NSIDC expert, Mark Serreze, said:
"There's nothing to be necessarily alarmed about. There's been open water at the pole before. We have no clear evidence at this point that this is related to global climate change."
During the summer of 2000 there was "a large body of ice-free water about 10 miles long and 3 miles wide near the pole". Also in 2000, Dr Claire Parkinson at NASA's Goddard Space Flight Center was quoted as saying: "The fact of having no ice at the pole is not so stunning."
The Tipping Point that wouldn't tip
Satellite records have been kept for polar sea ice over the last thirty years by the University Of Illinois. In 2007 2008, two very different records were set. The Arctic broke the previous record for the least sea ice area ever recorded, while the Antarctic broke the record for the most sea ice area ever recorded. Summed up over the entire earth, polar ice has remained constant. As seen below, there has been no net gain or loss of polar sea ice since records began.
Last week, Dr James Hansen from NASA spoke about how CO2 is affecting the polar ice caps.
"We see a tipping point occurring right before our eyes... The Arctic is the first tipping point and it's occurring exactly the way we said it would," he said.
Well, not exactly.
Hansen is only telling half the story. In the 1980s the same Dr Hansen wrote a paper titled Climate Sensitivity to Increasing Greenhouse Gases [pdf], in which he explained how CO2 causes "polar amplification." He predicted nearly symmetrical warming at both poles. As shown in Figure 2-2 from the article, Hansen calculated that both the Arctic and Antarctic would warm by 5-6 degrees Centigrade. His predictions were largely incorrect, as most of Antarctica has cooled and sea ice has rapidly expanded. The evidence does not support the theory.
In 2004, Dr Hansen returned to the subject. This time, he explained (pdf) that most of Arctic warming and melting is due to dirty snow from soot, not CO2.
"Soot snow/ice albedo climate forcing is not included in Intergovernmental Panel on Climate Change evaluations. This forcing is unusually effective, causing twice as much global warming as a CO2 forcing of the same magnitude," he wrote.
Once the snow dirties, it absorbs sunlight, warms, and quickly melts. Then the land and air above warms, causing higher temperature readings. This affects the Arctic more than the Antarctic simply because there aren't many people living near the Antarctic. The Arctic is polluted by European cities and oil fields in Siberia - where gas flaring generates huge amounts of soot.
In fact, scientists at the University of California have estimated that up to 94 per cent of Arctic melt is due to dirty snow.
In other words, then, Antarctic temperatures and ice are going the opposite direction of what Dr. Hansen predicted, and most of the Arctic warming is due to soot, not CO2. His own research directly contradicts his recent high-profile statements about the Arctic and CO2.
Dr Hansen also talks frequently about the unprecedented temperature rise in the Arctic, yet his own temperature records show that much of the Arctic (including Greenland) was warmer from 1920-1940 than now. The NASA graph below from Nuuk, Greenland is typical of long term records of the region.
Nuuk, Greenland is a key location because it is located in the southwest portion of the island and is not far from the mouth of the Jakobshavn Glacier - the most rapidly moving glacier in the world and a poster child for global warming campaigners. It is also the largest city and capital of Greenland, located just south of the Arctic Circle. NASA literature from the last few years focuses heavily on anomalous melt in southwest Greenland as a concern for sea level rise.
During the ice age scare in the 1970s the Arctic cooled dramatically, and is only now returning to temperatures comparable to sixty years ago. Most of the other Arctic locations with long-term records show similar trends. Long-term NASA temperature records in the Arctic are very sparse, but most show a pattern similar to Nuuk. Most of the other Arctic locations with long-term records show similar trends.
Another pollution problem reported by NASA is known as the Arctic Haze. This is a human-generated brown cloud which hovers over the Arctic and traps heat. Additionally, we know that the summer of 2007 had unusually low cloud cover in the Arctic, which contributed to the unusual melt. But probably the most important factor in the anomalous "melt" was a spate of strong winds which blew all summer up the Bering Strait, across the pole and out into the warm waters of the North Atlantic. This compressed the sea ice towards Greenland and revealed a large area of open water north of Siberia and Alaska.
But in 2008 we are not seeing that. The winds and temperatures in the Arctic are quite different, and as of today there is more ice than normal around Siberia. The Arctic melt season ends in about seven weeks because the sun will get too low. As of June 26, there is no indication that the North Pole is in danger of melting.
The BBC's Richard Black wrote an article last week claiming that Arctic Ice is melting "even faster than last year." Looking at the Cryosphere Today map, it is abundantly clear that ice is melting more slowly than last year. By the end of June, 2007 the Hudson Bay was essentially ice-free. This year it is close to normal, with cold temperatures predicted for most of the rest of the short melt season. Someone is apparently having trouble reading maps at either the BBC and/or NSIDC.
Last summer, the headlines read "First ever traversal of the Northwest Passage". This sounds very dramatic, except that it is entirely incorrect. As the BBC reported: "In 1905, Norwegian explorer Roald Amundsen became the first person to successfully navigate the Northwest Passage, in a wooden sailboat." The Northwest Passage has been navigated at least one hundred times over the last century.
"In fact, so little ice has never before been noted. The expedition all but established a record, sailing as far north as 81 degrees in ice-free water.
We must check back in seven weeks to see if the North Pole is ice-free. My money is on the experts being wrong - again. As the great physicist Dr Richard Feynman said, "Science is the belief in the ignorance of the experts." ®
Editor's note: This is one in an occasional series examining "PBEM", or "Policy-based Evidence Making".