Both sides of the "debate" over global warming have accused the other of cherry-picking data to suit their competing theses. The issue recently has focused on the past decade, and whether or not global warming in the 21st century has come to a "standstill", as the climate sceptics have suggested.
It is clear from the temperature data released yesterday by the Met Office and the World Meteorological Organisation that this decade has been the warmest since instrumental temperature records began in 1850. The first decade of this century was warmer than the 1990s, which were warmer than the 1980s.
Global temperature data for 2009, although still incomplete, indicates that it is likely to fall within the top five warmest years, and most of those have fallen within the past decade. It is apparent that global warming has not come to a "standstill".
Sceptics like to make a big deal of the point that 1998 was warmer than any year this century. But this is only true if you look at just one of the three global temperature databases – the data set used by the Met Office. This database does not in fact cover the Arctic, which is one of the fastest warming regions on Earth.
The Nasa data set, which does cover the Arctic, shows that 2005 is the hottest year on record. But both data sets are quite unequivocal in showing that the overall warming trend seen since 1850 has continued into the 21st century.
Many temperature records have been broken this century. March 2008 saw the warmest global land temperatures of any March, and June and August 2009 saw the warmest land and ocean temperatures in the southern hemisphere for any of those months on record. No amount of cherry-picking can alter these basic facts.