From 1951 to 2012, temperatures increased by an average of 0.12°C every decade. But from 1998 to 2012 this rise was of only 0.05°C. Though this discrepancy is often used as proof that climate change is not a current reality, researchers have found an explanation for this phenomenon and their conclusion is simple: global warming never took a break.
It appears that the earlier results showing a climate change hiatus may have resulted from a shift during the last couple of decades to a greater use of buoys for measuring sea surface temperatures. Buoys tend to give cooler readings than measurements taken from ships, which take their measurements from the temperature of the water in the oceans.
Thomas Karl, Director of the National Oceanic and Atmospheric Administration combined new data with improved calculations of air temperatures and land around the world, including land-based monitoring stations that extend into Arctic where observations have been sparse. They also included observations from 2013 and 2014, two of the warmest years ever recorded.
Furthermore, the year 1998 which was used as a reference was especially hot because of a strong El Niño that year. In comparison, the following years seemed cooler.
According to Thomas Karl, “global warming over the past 15 years is the strongest it has ever been since the latter half of the 20th century”. The overall global surface warming between 2000 and 2014 was 0.116°C per decade. For the authors of the study, this rise will probably be even higher when the data for Arctic’s warming will be complete.