Dramatic, Scorching Weather in Summer 2012 Linked to Global Warming

How hot is it going to get? Apparently it's going to be a scorcher. Scientists have calculated that intense heat like that in the summer of 2012 is up to four times more likely to occur now than in pre-industrial America. The root cause? The carbon dioxide in the atmosphere is heating things up.

During the summer of 2012, wildfires raged in the western U.S. while East Coast cities sweltered under the hot sun. Crops shriveled and died in the Midwest as farmers tried to recoup their losses. In fact, the July of 2012 was the hottest month in the history of U.S. record keeping. Unfortunately, it's likely we'll see more of these heat waves in the future.

In order to better understand the likelihood of this type of extreme weather occurring in the future, the researchers focused on understanding the physical processes that created the hazardous weather. More specifically, they examined how rare these conditions were over the history of available weather records over the last century. They then used climate models to quantify how the risk of such damaging weather has changed in the current climate of high greenhouse gas concentrations, as opposed to an era of significantly lower concentrations and no global warming.

"Going forward, if we want to understand and manage climate risks, it's more practically relevant to understand the likelihood of the hazard than to ask whether any particular disaster was caused by global warming," said Noah Diffenbaugh, one of the researchers, in a news release. "It's clear that our greenhouse gas emissions have increased the likelihood of some kinds of extremes, and it's clear that we're not optimally adapted to that new climate."

It's more important than ever to understand these risks. In 2012 alone, the U.S. suffered 11 extreme weather events. Each caused at least $1 billion in damage, which is a huge blow to the economy. Better understanding extreme weather events can help quantify the likelihood that society will face conditions that are similar to those that occurred in 2012. This, in turn, could help the U.S. and other countries prepare for these events in the future, which could help mitigate their impacts.

"Knowing how much our emissions have changed the likelihood of this kind of severe heat event can help us to minimize the impacts of the next heat wave, and to determine the value of avoiding future changes in climate," said Diffenbaugh.

The findings are published in the journal Bulletin of the American Meteorological Society.