It's Official: We Can Now Say Global Warming Has Made Some Weather Events Worse

From Hurricane Katrina to Superstorm Sandy, to last year’s devastating heat wave in India, the question never ceases to arise: Did global warming cause this?

That question has long made scientists squirm. They know the atmosphere is a complicated place. They know weather events are the result of a huge array of factors — like, say, the El Niño event that has been making weather really, really weird lately. And they know their notion of causation itself is far more complex and multifaceted than the colloquial understanding of the term “cause.”

But now, says a new report from the National Academy of Sciences exploring the attribution of extreme events to climate change, scientists can be at least a little bit less conservative about this.