So NASA has this tweet:
— NASA (@NASA) January 17, 2013
which points to a graphic from Climate 365 indicating that "9 of the 10 hottest years on record since 1880 have been in the last decade".
This has spawned a discussion on G+ (which I can't be arsed to read) which has more than 500 comments.
Statistics like these irritate me to no end.
First, the 133 years since 1880 represent 0.000000033% of the planet's 4 billion year history. Drawing a conclusion from such a small sample of time is the equivalent of finding a molecule of gold in the ocean and assuming that the planet must therefore be covered in gold.
Now, the earth has not had an atmosphere for 4 billion years. (To say nothing of the fact that the planet would have been VERY hot for those first billion years or so, as the planet cooled to rock.) Even if we assume 750 million years for the age of the atmosphere, 133 years is still only 0.00000173% of the time in question.
Furthermore, the earth has had wild temperature swings in the past. This has been proven. There is also evidence that the ice sheets may have disappeared entirely between 1.1 million and 400 thousand years ago. (You know, before humans were really around.) There is evidence that there were no polar ice caps at all 35 million years ago. (You know, before mostly everything that exists today was really around.) (The crocodiles may remember.)
Note that I am not suggesting that humans should not be good stewards of the planet on which we live; I am not suggesting we shouldn't do all to miminise our presence and negative externalities; I am suggesting, however, that poor use of statistics can be used to justify anything. Disraeli said it best with his "lies, damned lies, and statistics" quote. (Before you write to me – Twain was quoting Disraeli.)