ESRL Quarterly Newsletter - Fall 2010

Pointing Fingers

When the weather gets weird, how to place blame?

Massive floods in Pakistan this summer uprooted 20 million people. A heat wave and wildfires in Russia conspired to kill thousands more. Nevada is hotter than ever.

Such news is distressing on many levels to Kelly Redmond, Deputy Director of the Western Regional Climate Center in Reno, NV. First are the human lives and livelihoods lost. But there’s also the struggle of federal scientists to explain—on time scales of interest to policy makers and everyday people—what happened.

Redmond’s phone has been ringing a lot recently. “Why’s it so hot in Nevada?” one reporter asked. “What’s going on in California?” asked another. “Is this climate change?” He can’t always answer.

“We hear the same questions over and over after extreme events,” said ESRL’s Marty Hoerling, who organized an international meeting on the attribution of climate-related events in Broomfield in August. “Why did it happen? Has this ever happened before? When could it happen again?” 

About 50 scientists (including Redmond), communications experts, water managers, and other users of climate information spent two days identifing what can be done to find and communicate answers that might be useful to people.

To start, researchers often need to dissect the relative roles of natural variability (such as El Niño-Southern Oscillation), random weather, and climate change in a weather disaster—a drought, a flood, or deadly heat. Such “attribution” investigations aren’t easy and may require careful analysis of historic data, substantial computing power to evaluate climate projections, and time to asses published scientific papers on various climate patterns that might have contributed.

Yet the answers are often of critical importance to people on the ground, said ESRL’s Roger Pulwarty (PSD and the National Integrated Drought Information System). If a climate pattern is variable, perhaps depending on natural oscillations in sea-surface temperatures, then a period of crippling aridity, for example, might end soon with rain. If an attribution study shows a strong role of climate change, the conclusions may be different.

“If the trend is persistent, well, that matters a great deal in terms of the scenarios that people in the Four Corners region develop to deal with it,” Pulwarty said.

Peter Stott from the UK Meteorology Office, told the group he had hoped to arrive better prepared for the meeting, but was inundated with media calls about severe weather in Pakistan and Russia.

“Last week was a bit of an object lesson in why we need this sort of activity,” Stott said.

After Europe’s deadly 2003 heat wave, Stott and his colleagues conducted a careful attribution study and found that the deadly conditions in Europe were two to four times more likely in a warmed world than in the absence of climate change.

That kind of clear result, communicated well, is an incredibly powerful message for many people, said Ed Maibach, Director of the Center for Climate Change Communication at George Mason University, and Susan Hassol of Climate Communication, who participated in the workshop.

Maibach offered lessons from his research into how people make decisions—including the sobering news that scientific “findings” seldom have much impact. “Experience trumps analysis,” Maibach said. “If we want people to grapple with this, we need local, concrete, real stories.”

Workshop participants agreed that to respond to public interest in extreme events and decision makers’ needs, attribution efforts must be timely, even “near real-time.” That’s challenging, given that strong science and review take time.

During the meeting, breakout groups discussed ways to respond to user need with quick turn-around science and communications. Suggestions were diverse: An international team of attribution experts could be “activated” when extreme events approach. Or response could be staged, starting with a quick assessment of historic data to help the media put events into context and ending with a full attribution study conducted, knowing that it may not be done on time to catch the wave of public interest.

Workshop participants also agreed that in general, a strong attribution enterprise would make it possible to improve projections of future climate, including extreme events. “The events we’ve seen this summer, the urgency compels us,” said Hoerling. “We want to do this faster and more effectively.”