The WMO has a report out this week about the climate of 2013, and while you can read the whole thing in 20 minutes, a special edition at the end is a must read. You can get the entire report here, but I am reproducing the last section, because it is a short but fascinating discussion of an attribution study. In atmospheric science, an attribution study looks at the causes for a particular event or observation, and one of the most famous was by Dr. Ben Santer (Lawrence-Livermore Nat. Lab.) who showed conclusively that the warming over the past century was due to greenhouse gases and not the Sun.

Regarding the study mentioned in the WMO report, it shows that Australia’s torrid summer in 2013 was about 5 times more likely to occur because of the higher greenhouse gases in the Earth’s atmosphere. Attribution studies are becoming a very good way to explain to the public how climate change is already affecting our day-to-day lives and our pocket books.

Explaining the summer 2012/2013 and annual
2013 record warmth in Australia

Sophie C Lewis and David J Karoly, ARC Centre of Excellence for Climate System Science,
University of Melbourne, Australia