In Canada, "Polar 5", a research aircraft, has ended its recent Arctic expedition today. During the flight, scientists were measuring the ice thickness in regions that have never been seen from airplanes. The result: the sea ice is apparently thicker than scientists suspected. Under normal conditions, the ice is formed within two years and ends up being slightly above 2 meters of thickness. "Here, the thickness was as high as four meters," said the spokesperson for the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven. According to the scientists, this conclusion seems to contradict the warming of the...