In order to understand recent behavior of polar ice and have some visibility into the future, we need to look at it from an historical perspective. A good place to start the investigation is Greenland, which is often described by official sources as experiencing a meltdown. The BBC has famously warned us “If the ice cap were to completely disappear, global sea levels would rise by 6.5m (21 feet).”
NASA’s Goddard Institute of Space Studies (GISS) has long term temperature records for several locations in Greenland and Iceland. The graph below (see PDF) shows average annual temperatures in the Greenland capital for the last 100 years.
Over the last 30 years, Godthab has warmed by several degrees, as shown with the red line. But the one hundred year trend (yellow line) shows a slight cooling. Peak yearly temperatures during the past decade are about one degree cooler than peak years in the 1930s and 1940s.
There also appears to be a cyclical pattern of warming and cooling in Godthab. Temperatures warmed until 1940, cooled in the 1960s and 1970s, and warmed again starting in the 1980s. The graph below shows the Godthab temperature record again, this time with the ten year running mean in red.
to download PDF file to read FULL report from Steve Goddard