Advocates for action to address climate change are making messaging hay out of this year's seemingly endless procession of storms, droughts, heat and wildfires.
As a mild winter in many parts of the country was followed by a warm spring and a hot summer, environmental groups have been firing off press releases and releasing reports at a steady clip.
Extreme summer heat is happening much more frequently now than it did decades ago and is affecting more Americans, climate change activist and NASA climatologist James Hansen wrote in a provocative op-ed in The Washington Post over the weekend.
Hansen said his data allowed him to attribute heat waves in Europe and Russia in 2003 and 2010, respectively, and last year's drought in Texas and Oklahoma to climate change. "And once the data are gathered in a few weeks' time, it's likely that the same will be true for the extremely hot summer the United States is suffering through right now," he said. The United States experienced the hottest July ever recorded this year, breaking the 1936 record, with the lower 48 states sweating their way through an average temperature of nearly 78 degrees Fahrenheit.
Climate change is already disrupting rainfall and snowfall patterns throughout the United States, the advocacy group Environment America said in its own report last week.
The group indicated that storms dumping high levels of precipitation have increased in frequency by about a quarter since 1948 with some regions of the country faring worse than others. New England has seen the biggest change, with high-precipitation rain and snowstorms up 61 percent in the same period. Oregon is the only state that has seen a statistically significant decline in extreme precipitation events, it said.
Environment America's federal global warming program director, Nathan Willcox, said the public was taking notice of these weather events, and he predicted that mounting concern would finally put climate change back on the legislative table.
"I think that the more and more that Americans are looking in their backyards and seeing extreme weather events, and they're seeing record heat happening all across the country, the more that they will be reaching out to their politicians, and we will hopefully be able to change that tide moving forward and actually get some more action from decisionmakers," Willcox said on a call with reporters.
Environmentalists' allies on Capitol Hill seem to be humming the same tune. Sens. Barbara Boxer (D-Calif.), John Kerry (D-Mass.), Bernie Sanders (I-Vt.), Sheldon Whitehouse (D-R.I.) and others all came to the Senate floor in the weeks before the August recess to talk about the effect carbon dioxide emissions are already having on conditions around the country and to urge action.
Senate Majority Leader Harry Reid (D-Nev.) said yesterday at his annual clean energy summit in Las Vegas that recent weather events proved that climate skeptics are "on the other side of reality" (E&ENews PM, Aug. 7).
In the House, Reps. Henry Waxman (D-Calif.) and Bobby Rush (D-Ill.) asked the Republican leadership of the Energy and Commerce Committee for a hearing, citing a study released by the National Oceanic and Atmospheric Administration in July that showed the United States had set more than 40,000 high temperature records this year (E&ENews PM, July 13).
The two Democrats cited everything from the Texas drought to the Washington, D.C.-area derecho as evidence that lawmakers should take another look at climate change.
Whitehouse said in a recent interview that constituents responded to the message that climate change is already making weather patterns unstable.
"I think it is persuasive," he said, "because I think the climate change debate has been theoretical for a lot of people."
But as Americans become aware of the events that are going on across the country, from droughts to flooding to wildfires, he said, "that very much connects to their experience."
"And when they not only see it happening once to themselves, but read about it happening across the country and over and over again as news brings in these reports, I think that makes a strong impression," Whitehouse said.
Anthony Leiserowitz, director of Yale University's Project on Climate Change Communication, said that repeated extreme weather events represent a "teachable moment" on climate change.
While the media have decreased coverage of climate change over the past few years as it has slipped from the legislative agenda, they cannot help but keep the public informed about the storms and droughts reverberating around the country, he said. And a particularly active season might lead the public to consider whether things might be changing for a reason.
This is especially true, Leiserowitz said, for people who experience repeated extreme weather in their own backyard.
"As [former House Speaker] Tip O'Neill famously quipped," he said, "'All politics is local.'"
Jon Krosnick, a communication and psychology professor at Stanford University, said the environmental community does appear to be betting that extreme weather will be the "magic bullet" that will finally convince America's voting public that climate change exists and deserves immediate attention.
"It's almost as if the CEO of messages for this community came down from the mountain with the tablets and said, 'Here's the latest agenda, everyone. Jump on this one,'" he said.
A double-edged sword?
But although that message may make sense intuitively, Krosnick said, there is no evidence that people will accept man-made climate change even if they are prompted to learn more about it after an unusually active season.
And linking weather and climate in the public's mind might prove to be a double-edged sword, he said.
"The minute we go through a few years of very stable temperatures or unusually low temperatures, then the skeptics are going to say, 'Aha, you see!'" Krosnick said. "This doesn't seem like a winning long-term strategy, even if it did work in the short term."
Leiserowitz conceded that committed skeptics -- or those he classifies as "dismissive" of man-made climate change -- will embrace cold weather as evidence that concern about climate change is overblown.
Vocal climate skeptic Sen. James Inhofe (R-Okla.) has done that repeatedly. The Environment and Public Works Committee ranking member frequently talks about the igloo his daughter Molly and her family built in front of the Capitol after particularly heavy snowfall in 2010, accompanied by a sign saying "Al Gore's new home -- honk if you love global warming." A blown-up photograph of the family made two separate appearances last week during the committee's hearing on climate science.
But Leiserowitz said his polling shows that members of the public who are not committed to a viewpoint on climate change may be persuaded by repeated exposure to extreme weather events that appear to be accelerating in frequency and intensity. And this new belief and interest in climate change might stick, even if the weather becomes cold or stable for a while, he said.
"People learn," Leiserowitz said. "People aren't just simply puppets being pulled one way or the other depending on what's going on with the weather. They learned from what's going on. They remember what's going on."
Advocates for climate change science say the weather can be a valuable communication tool, but they emphasize that communicators must be careful not to misstate the relationship between weather and climate.
"It is important to provide the larger climate context to extreme weather events, but there is a risk if you overstep the science," said Paul Hanle, president and CEO of Climate Central, a nonprofit that focuses on communicating about climate change.
Hanle said his group strives to communicate that although no single event can be linked to climate change, the types of events that have been on display in recent years -- very high average temperatures, droughts, more severe storms, wildfires -- "are entirely consistent with what the broad consensus of climate scientists have been predicting for years." He added that the only surprise is that those events seem to be happening with increasing regularity years earlier than scientists once predicted.
Jay Gulledge, a senior scientist at the Center for Climate and Energy Solutions, said that he has seen both responsible and irresponsible messaging on the link between climate change and weather coming from the environmental community.
"It's somewhat nuanced, and you may lose some people that way, but you tell the truth," he said.
The truth, Gulledge said, is that scientists can say with confidence that certain kinds of weather events appear to be picking up steam in response to man-made warming. But data do not exist to support the same conclusion for other kinds of events.
"For example, I have no idea if the derecho was juiced up by climate change," he said, referring to the damaging high-intensity windstorm that hit the D.C. region in July.
"We don't understand the physics of that kind of system well enough," he added.
A data-driven argument?
In order to establish the link, Gulledge said, scientists need a theoretical understanding of the physics of how an event would be affected by man-made warming. They then must collect data through observations that would show whether weather patterns are changing as would be expected from the theory, and then use models to reconcile the theory with the observations, projecting the risk into the future.
These three requirements do not exist for some types of events, including tornadoes, Gulledge said. Scientists lack the data, don't understand the physics and can't model them. More small tornadoes have been reported in recent decades, he said, but that could have more to do with the advent of cellphones, which allow people to report what they see from the road, than with an actual uptick in the number of tornadoes.
But extreme heat, drought, fires and heavy precipitation can all be shown to have increased in recent decades in part due to climate change, he said.
When it comes to communicating the link, Gulledge said the emphasis should not be on convincing the public of the effect climate change will have or has already had on weather. Instead, he said, communicators should focus on educating the public.
"If it's real, you talk about it," he said. "If it's hard to understand, you talk about it over and over and over again, because that's how you learn."
The public is more likely to be interested in learning about climate change because people are noticing changes outside their own windows, he said.
"People only pay attention when they're asking the question themselves," he said.