The media portrays a dramatic image of how the ice is melting in the polar regions as a consequence of global warming. We are warned that the North Pole might become icefree during the summer months at the end of this century and that the polar bears might become extinct due to this development.
But is this really a realistic image? Sure, there is research that indicates that the ice sheets are being reduced, but there are also studies that show the complete opposite. An example of this is a study in the scientific journal Geophysical Research Letter where the Swedish researcher Peter Winsor compares data collected by submarines below the Arctic ice. His conclusions are that the thickness of the ice has been almost constant between 1986 and 1997.
If you look at the South Pole there are studies that show an increase in the mass of the ice. In a study published in the journal Nature a number of polar researchers showed that they had observed a net cooling of 0.7 degrees in the region between 1986 and 2000. Another study published in Science showed that the East-Antarctic ice sheet had grown with 45 million metric tones between 1992 and 2003.
Are the ices growing or melting? The simple answer is that there exist studies that point to both directions, perhaps indicating that scientists know relatively little about global climate. But what counts to most ordinary people is what media is reporting, and media is often highlighting the most alarming studies and seldom report of studies that go against the notion that human activity leads to global warming. To put it simply, the news is filtered through an environmentalist view of the world.
An interesting example of how media sometimes gets it wrong is how journalists reported that there had never been so little ice in the Arctic than in 2005. This claim was based on satellite images by NASA which showed that the geographic extent of the ice sheet had never been so small since measurement began in 1979. One must however keep in fact that about half of the ice in the Arctic melts each summer and that two months before this measurment the extent of the ice sheet was the same as the previous year. The problem is that satellite images show the surface of the ice but not the thickness.
Capten Årnell at the summer expedition with the polar-ship Oden could tell that he had never seen so much ice in the Arctic than in 2005. It was with great difficulty that he had passed through the region. What had happened in 2005 seems to be that the ice had packed densely against the Canadian part of the Arctic. The geographical extent had been reduced but the ice was thicker.
As for polar bears, much points to that their numbers are increasing rather than diminishing. Mitch Taylor, a Canadian expert on animal populations, estimates that the number of polar bears in Canada has increased from 12 000 to 15 000 the past decade. Steven C Amstrup and his college have studied a population of polar bears in Alaska and reported that the number of females had increased from 600 to 900 between 1976 and 1992. Even a report from the WWF which is entitled "Polar bears at risk" and warns that the populations of the polar bears might become extinct due to global warming, supports that the number of polar bears is increasing. In the report the polar bears in the world are divided into 20 populations. It shows out that only 2 of these populations are decreasing, while 10 are stable, 5 are growing and 3 are not possible to comment about.
Global climate is an important issue to debate, but it is sad that what is communicated often has a clear shifting towards the worst-case scenarios and the doomsday theories. There is no reason to scare people by giving them only one side of the argument.
March 18, 2006