This winter has involved a lot of debate on climate changed based around anecdotes: ‘it is snowing in England, therefore it isn’t happening’ or ‘there are terrible fires in Austalia so it is.’ In the end, while anecdotes can provide the imagery that motivates people to act, it is only through the analysis of large amounts of data that high quality conclusions can be reached.
On that front, the global glacier index update on RealClimate is a good example. They examine data on the mass balances of glaciers around the world between 1980 and present, revealing a very clear trend. Similar statistical analysis is performed on the terminus behaviour of the glaciers.
Human beings have a tendency to place undue weight on things we happened to personally observe recently. It’s part of a set of heuristics that aids our functioning in some circumstances, but it does us a great disservice when we are contemplating phenomena that are exterior to our normal modes of operation.