The Bulletin of the American Meteorological Society released a report entitled Explaining Extreme Events of 2012 from a Climate Perspective. The report was compiled by more than 70 scientists on 18 research teams from around the world, and examined the causes of 12 extreme weather events that occurred on five continents and in the Arctic in 2012.

The report shows the intensity and evolution of the storms is largely due to effects of natural weather and climate fluctuations. In some events, like droughts, heat waves, and floods, evidence showed that the emission of greenhouse gases from human-induced climate change contributed to the extreme event. The report concludes that while the events are a natural part of the climate system, the influence of human-induced climate change makes the event more likely to occur.

Sources: American Meteorological Society, National Oceanic and Atmospheric Administration