Recent headlines have referred to the fact that the arctic ice has melted to a record low and many are using this as evidence to support the theory of global warming.
The earth is tilted on an axis of 23.5 degrees in relation to its orbit of the sun. This means that in winter the sun is below the horizon in Arctic, plunging the whole region into perpetual darkness and causing temperatures to plummet to around 40 to 60 degrees below zero. At this time the whole of the arctic sea freezes over, but during the summer the opposite occurs. The sun is constantly above the horizon and temperatures reach into the 30’s causing the sea ice to melt. Lately the sea ice has been melting more and more, leading some to claim that the reason is manmade global warming.
The problem is that the people who make these claims, and the authors of the articles that report on the shrinking sea ice do not take into account the history of the Arctic and the natural cycle of the sea ice. Only by studying historic records could we understand the natural variations, and put the current levels into context.
Walt Meier, a scientist at the National Snow and Ice Data Center in Boulder, Colorado, took the first steps to comparing current data with previous records and concluded that “in the context of what’s happened in the last several years and throughout the satellite record, it’s an indication that the Arctic sea ice cover is fundamentally changing.”
Unfortunately Walt just didn’t look back far enough. The “satellite record” which he used only started in 1979 when the polar orbiting satellites were brought online. His study of the 33 years of records showed that there was no change in the amount of Arctic sea ice until the late 1990’s and this lends itself to support a different theory, that the sea ice is melting at the moment because the North Atlantic Ocean is in the warming phase of its long term cooling and warming cycle known as the Atlantic Multidecadal Oscillation (AMO).
In the mid 1980’s Dr. William Gray of Colorado State University used this cycle of warming and cooling to correctly forecast the era of increased hurricane activity we are experiencing now. Another natural result of the warming and cooling cycle will be a that the sea ice melts quicker, but to test this theory we must look for historic references to the amount of sea ice present in the Arctic during a previous warming phase in the Atlantic.
During the 1930’s the North Atlantic was in such a phase, and it was reported that the Soviet ice-breaker ships were able to sail waters that had never before been open for travel, the ship Sadko even managed to sail within 500 miles of the North Pole. And the average coal shipping season at Spitsbergen, Norway almost doubled in length from 95 days from 1909-1912 to 175 days from 1930 to 1938 due to the lack of sea ice.
Maybe global warming should not be given as much credit as it is for the current extreme weathers that are being experienced around the world.
By. Charles Kennedy of Oilprice.com