A new analysis released Thursday of 12 extreme weather events in 2012 found "compelling evidence that human-caused change was a factor contributing to the event" in at least half of them, according to Thomas Karl, director of the Climatic Data Center at the National Oceanic and Atmospheric Administration.
The paper, which was published in the Bulletin of the American Meteorological Society, pulls together 19 studies on 12 separate weather events in the U.S. and around the world in 2012. Researchers looked at how climate change affected the amount of flooding that occurred due to Hurricane Sandy.
They found that sea-level rise caused by climate change has nearly doubled the probability of flooding like that storm caused in many areas of the East Coast, when compared to the chance of such an event in 1950.
Heat waves and some heavy rainfall were also among the weather events that could be linked to climate change, according to the paper. Heat waves like those experienced in the spring and summer of 2012 are four times more likely to occur now because of climate change. And while there are other factors, like natural variability in climate, that can cause higher temperatures, a third of responsibility for the high temperatures the eastern U.S. saw in March and May 2012 were because of climate change, the paper found.