Is Global Warming to Blame for this Summer’s Extreme Heat and Drought?

It’s a great question. It’s simple, compelling, and it makes for good headlines. That’s why so many people are talking about it. But it’s the wrong question.

I’ve been corresponding with climate scientists, educators, and journalists lately about this summer’s extreme weather. Our discussions have convinced me that this is a great question for advancing scientific research, but it is a distraction for the rest of us.

It’s not that the question is irrelevant. We all want to know whether global warming is already becoming palpable in our hometowns. If so, then climate change is manifesting much sooner than expected, and that’s news. Recent history has made us extra sensitive too, with record-breaking storm damage, heavy snows, floods and, now, drought and the hottest July ever recorded across most of the Lower 48 states.

Is this climate change…already?

The question creates two significant problems, and the first is a familiar one. Climate is average weather and is measured in long-term trends, not today’s local events. As James Hansen’s team wrote in their recent paper, “The location and timing of weather extremes depends on many factors and to a large degree is a matter of chance.”[1] In other words, blaming any local event entirely on the underlying trends makes no sense.

Does that mean the answer is no? Well, not really because the underlying warming trend pushes the weather, making extreme heat even hotter and more likely, and making droughts drier and more likely as well. Climate Central recently attributed the following explanation to Kevin Trenberth of the National Center for Atmospheric Research: “global warming helps make droughts hotter, and therefore drier, than they would be without human influence.” Meanwhile, Hansen’s team concluded that the number and extremity of heat waves have been rising, and they attribute these increases to global warming.

The relationship between weather and climate is very complex. Herein lies the second problem: simple questions beg for simple answers. Unfortunately, complex and hotly debated answers to our beautifully simple question accidentally reinforce the popular myth that global warming science is still unsettled.

Parsing the human influence on extreme weather events is cutting edge research. The cutting edge offers good material for the news, of course, because the questions are always compelling. But it also promotes a view of climate science as an endless debate about unanswered questions. Given what is at stake, plus ongoing efforts by deniers to promote the myth of scientific uncertainty, this is hardly the most productive way to help people engage.

Fortunately, there is an equally exquisite alternative to this difficult question.

The summer of 2012 presents a “teachable moment” with a lesson about experiencing the future first hand. New, different weather is exactly what climate change looks like: more extreme heat, more droughts, more storms, more wildfires, more costly damage, and so on.

Sure, nature dishes out harsh weather on its own, but getting hung up on the degree to which this summer’s heat waves are natural or human-caused is a distraction. If we can experience America’s hottest July on record, coupled with widespread drought at a time when global warming has advanced less than 1°C, the relevant question is what summers will be like when we reach 3°C, 4°C or 6°C. Given that greenhouse gas emissions have been rising along the so-called “worst case scenario” path since 2000, that’s exactly where we are headed unless we make different choices very soon.

We are getting a taste of the future right now. That’s the lesson.

Climate change is an immediate concern to nearly every American community, not some abstract discussion about far-off consequences or a technical debate about leading edge research. We are already vulnerable to drought, heat, storms, wildfires, smog, and rising costs.

Do we know how to reduce our vulnerability? A 2009 National Research Council study said no: “Government agencies, private organizations, and individuals whose futures will be affected by climate change are unprepared, both conceptually and practically, for meeting the challenges and opportunities it presents.”

I suggest that it’s time to figure out what to do, and we should start by asking the right question. Given what we are experiencing in 2012, what will summers be like in the next ten, twenty, and fifty years?

Research shows that when people grapple with their vulnerability they suddenly begin asking how we can reduce global warming in the first place. That’s the right discussion for communicators, the news media, and the rest of us to encourage.



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