World map vector: Antun Hirsman/Shutterstock

Major earthquakes thousands of miles away can trigger reflex quakes in areas where fluids have been injected into the ground from fracking and other industrial operations, according to a study published in the journal Science on Thursday.

Previous studies, covered in a recent Mother Jones feature from Michael Behar, have shown that injecting fluids into the ground can increase the seismicity of a region. This latest study shows that earthquakes can tip off smaller quakes in far-away areas where fluid has been pumped underground.

Fracking waste fluids "kind of act as a pressurized cushion," said a lead author on the study.

The scientists looked at three big quakes: the Tohuku-oki earthquake in Japan in 2011 (magnitude 9), the Maule in Chile in 2011 (an 8.8 magnitude), and the Sumatra in Indonesia in 2012 (an 8.6). They found that, as much as 20 months later, those major quakes triggered smaller ones in places in the Midwestern US where fluids have been pumped underground for energy extraction.

"[The fluids] kind of act as a pressurized cushion," lead author Nicholas van der Elst of the Lamont-Doherty Earth Observatory at Columbia University explained to Mother Jones. "They make it easier for the fault to slide."

The finding is not entirely surprising, said van der Elst. Scientists have known for a long time that areas with naturally high subsurface fluid pressures—places like Yellowstone, for example—can see an uptick in seismic activity after a major earthquake even very far away. But this is the first time they've found a link between remote quakes and seismic activity in places where human activity has increased the fluid pressure via underground injections.

"It happens in places where fluid pressures are naturally high, so we're not so surprised it happens in places where fluid pressures are artificially high," he said.

The study looked specifically at Prague, Oklahoma, which features prominently in Behar's piece. The study links the increased tremors in Prague, which has a number of injection wells nearby, to Chile's February 27, 2010, quake. The study also found that big quakes in Japan and Indonesia triggered quakes in areas of western Texas and southern Colorado with many injection wells. The study is "additional evidence that fluids really are driving the increase in earthquakes at these sites," said van der Elst.

how fracking causes earthquakes

Animated GIF: fracked Up?

Drillers inject high-pressure fluids into a hydraulic fracturing well, making slight fissures in the shale that release natural gas. The wastewater that flows back up with the gas is then transported to disposal wells, where it is injected deep into porous rock. Scientists now believe that the pressure and lubrication of that wastewater can cause faults to slip and unleash an earthquake.

Illustration: Leanne Kroll. Animation: Brett Brownell

Hurricane Isabel from the International Space Station.

It's the month of July, right before the Atlantic hurricane season really gets chugging. And there are already signs that a busy year might be on the way, chief among them the unusual early appearance of a "Cape Verde-type" storm. These storms are typically sparked by atmospheric waves traveling all the way from the coast of Africa, and generally don't appear until later in the hurricane season.

And suddenly, an MIT scientist—who's arguably the world's top expert on hurricanes—publishes a bombshell paper in a top scientific journal. His suggestion? That global warming might be making the most destructive storms on Earth even more dangerous.

If you're feeling a sense of scientific déjà vu right now, that's understandable. For not only are these events currently unfolding—they also all occurred in July of 2005, just before hurricanes Katrina, Rita, and Wilma devastated Florida and the Gulf Coast.

MIT's Kerry Emanuel. James West

On July 31 of that year, MIT hurricane specialist Kerry Emanuel published a paper in the journal Nature suggesting that hurricanes had gotten much stronger over the past three decades, likely prompted by a rise in sea-surface temperatures that, in turn, is directly tied to global warming. The study upended a prior consensus that any major climate-induced changes to hurricanes would be much further in the future, and ignited a furious scientific debate—one that was only amplified by the intense hurricanes that soon began slamming the U.S. coastline.

And now this year, it looks like history may be repeating itself. Another July has rolled around, with more weird early season storm activity. And sure enough, Emanuel is back with a new paper challenging the consensus on hurricanes and global warming.

Following the explosive 2005 debate, scientists gradually settled on a new conclusion. Storms are likely to be stronger on average in the future and to dump more destructive rainfall, they agreed, but—in a bit of a reprieve—they're also likely to be less numerous overall. Or as a recent summary of the state of scientific understanding put it, an "increase in intense storm numbers is projected despite a likely decrease (or little change) in the global numbers of all tropical storms."

While it may sound rather mild, this conclusion could hardly be called good news. The strongest storms—the Katrinas—cause the most damage, so a future with more of them is likely to be a pretty grim one. “I like to emphasize that for societal purposes, the big deal is the increase in the frequency of the high category events,” explains Emanuel. Nonetheless, to the untrained ear the current view sounds like a tradeoff of strength versus numbers, and thus kind of a wash. “I think that was a bad way for us to put it,” says Emanuel of the consensus view.

But Emanuel no longer thinks that consensus is necessarily correct. In his new paper in the Proceedings of the National Academy of Sciences, he uses a procedure known as “downscaling”—combining together global climate models with a much higher resolution hurricane model—to show that hurricanes may be both more numerous and also more intense going forward. The region of the world projected to suffer most is the Northwest Pacific, which features the strongest storms on earth—Pacific super-typhoons that slam Japan, the Philippines, and other nearby nations and islands. But the North Atlantic region won’t be spared in Emanuel’s scenarios. 

Why does Emanuel’s new study diverge from past research? One reason may be that it employs six climate models from a suite that are being used in the U.N. Intergovernmental Panel on Climate Change’s forthcoming Fifth Assessment Report. And according to Emanuel, these newer models have a different treatment of so-called sulfate aerosol emissions, which come from the burning of coal and actually tend to reflect sunlight away from the planet and its oceans, producing a net cooling effect.

The newer models project a greater reduction in future aerosol pollution from countries like India and China. And as Emanuel explains, his “hunch” is that the disturbing hurricane response that his study found is a perverse result of this seemingly “good news” aspect of the models’ projections. In other words, if you clean up the air, you can actually worsen global warming and also, perhaps, hurricanes.

The debate over Emanuel’s new results has just begun—but already, the work has been challenged. The divergent findings, says hurricane expert Greg Holland of the National Center for Atmospheric Research, “indicate that care needs to be taken in being too explicit with climate predictions of changes in tropical cyclone frequency at this stage.” 

Up until now, the news that the hurricanes of the future will be stronger, and will unleash even stronger tropical downpours, was bad enough. But at least we were supposed to be getting off the hook when it came to storm numbers. Now, says Emanuel, even that minor bit of good news is in question.

Global average temperatures by decade.

Eli Lehrer wants conservatives to take global warming seriously. He's the president of the R Street Institute, a free-market think tank whose board includes former South Carolina Republican Rep. Bob Inglis—a celebrated conservative apostate on climate change—and another freethinking conservative, David Frum.

Recently, Lehrer took to the pages of the Weekly Standard to make the conservative case for a carbon tax (while also criticizing President Obama's recent climate proposals). "Rather than pretend climate change isn't a problem, there are ample opportunities for Republicans to point out the obvious flaws in the left's plans to deal with it and offer alternatives of their own," writes Lehrer. He adds that the scientific debate over whether humans are causing climate change is pretty much over:

Nobody seriously involved in the policy debate over climate change—not even those the left unfairly labels as "deniers"—actually denies that humans influence global climate. There's also no dispute that the Earth is warmer than it was before the Industrial Revolution or that carbon dioxide and other greenhouse gases can trap heat energy.

Unfortunately, however, it looks like many other influential voices on the right are still trying to find "scientific" reasons to discount or minimize global warming.

Lately, a favored argument is to suggest that global warming may have stopped after the year 1998. Versions of this claim were articulated by Washington Post columnist Charles Krauthammer, Texas Sen. Ted Cruz, and numerous others in response to Obama's recent climate speech. Or as Krauthammer put it: "Global temperatures have been flat for 16 years—a curious time to unveil a grand, hugely costly, socially disruptive anti-warming program."

This is very misleading. First, if you're simply looking at record temperature years, then 2010 and 2005 both beat 1998 for the highest global average temperature, according to NASA. The World Meteorological Organization agrees that 2010 is the hottest year on record, "followed closely by 2005." The WMO also notes that the 2000s were the hottest decade on record (see graphic above).

A more sophisticated version of this latest "skeptic" argument is to note that the rate of global warming in the last 15 years has been slower, or has been "leveling off." But as the blog Skeptical Science points out, that's only true for atmospheric temperatures—which, in turn, only reflect a small part of the overall global warming picture. Warming of other parts of the planet, and especially the oceans, proceeds apace.

"Conservatives should care about global warming," writes Lehrer at the end of his Weekly Standard article. Alas, many still seem to be looking for a reason not to.

If you watched President Obama's major speech on climate change, you may have noticed a recurrent phrase: "our children." The president said the word "children" 15 separate times in the speech. He also spoke repeatedly about "future generations" and how a sweltering planet imperils them. The threat of climate itself, meanwhile, garnered considerable scientific detail in the speech, replete with references to dangerous and destructive impacts that are already occurring—from rising seas to parched land and torched forests.

"I refuse to condemn your generation and future generations to a planet that's beyond fixing," the president said.

When you stop and think about it for a minute, the messaging change here is pretty extraordinary. After all, four years ago the administration's central talking point on climate change did not mention climate change. Rather, the idea was that greening our economy would confer a major benefit in the form of a profusion of green jobs. "It's ironic that the administration, which helped launch 'Don't talk about climate change, talk about economics and jobs,' has flipped to 'Let's talk about climate change and frame it in moral terms,'" says Joe Romm, a former Clinton administration clean energy official and editor of the leading climate blog Climate Progress. Meanwhile, as the Google Trends search above shows, interest in "green jobs" peaked early in Obama's first term and has been declining ever since.

So how—and why—did Obama finally change how he pitches climate action to the public? 

To answer that question, let's first warp back to the economically torturous spring of 2009. Such was the backdrop for a now infamous high-level White House meeting with environmentalists, in which members of the green community were reportedly instructed not to talk about the science of climate change. That wasn't going to be the White House's message, they learned—rather, the focus would be on clean energy and jobs. Thus was the groundwork laid for Obama's later "climate silence," as increasingly fed-up climate hawk activists began to put it.

That same spring, the Dow Jones Industrial Average crashed, and unemployment soared. No wonder, then, that the White House—in a strategy allegedly designed by then senior adviser David Axelrod—decided to sell climate action as an economic positive. Not only did the frame seem a good fit for the times, it also had the benefit of leapfrogging past often bewildering fights over the science of climate change. After the "ClimateGate" pseudoscandal hit later that year, unleashing unprecedented attacks on climate researchers, the economic message must have seemed like a pretty wise idea.

After Solyndra, the green jobs message could be met with counterclaims about corruption and government waste.

Alas, the White House's favored cap-and-trade bill—pitched, economically, as the "American Clean Energy and Security Act"—died in the Senate in 2010. Meanwhile, the clean energy message fell under attack from political conservatives who went looking for scandal in government-supported clean energy projects, and eventually came upon the solar cell manufacturer Solyndra, which had received a large government loan guarantee but went bankrupt in late 2011. From a communications standpoint, the accuracy of the right's allegations about Solyndra—which have since been disproved—doesn't really matter. What counts is that the green jobs message could now be met with counterclaims about corruption and government waste.

By the end of 2011, then, climate change looked like a political loser, and green jobs had tumbled into the maw of political polarization. On climate, Obama became a man without a message—which probably explains why, especially during the presidential campaign, he didn't talk much about the issue (his 2012 Democratic National Committee acceptance speech—which in effect previewed his new climate message—being a notable exception).

But at the same time, extreme weather was really starting to catch our attention. The year 2011 saw a stunning 14 separate weather events, ranging from Hurricane Irene to multiple tornado strikes, whose damage exceeded $1 billion. That was a new record for the number of different high-cost disasters in a single year. Then came 2012, and winter heat that seemed simply unreal. It felt as if the normal pattern of changing seasons had simply ceased to exist.

Not only did this weird weather start to change public opinion—it changed scientists themselves. Some, like Kevin Trenberth of the National Center for Atmospheric Research, began to question the old adage that it is impossible to link any particular weather event to climate change. Others, at minimum, began to wonder whether that was the only thing to be said about the matter. "If you go back five years, it was very hard to find a lot of scientists making the extreme weather connection," Romm says. "That changed, because the last two and a half years have just been jaw dropping." 

Then, environmental strategists themselves—accompanied by public opinion experts—started making the case that the climate issue, messaged properly, could be a political winner, rather than the communications dog that some in the White House seemed to think it was.

One of the most important of those strategists was Betsy Taylor of Breakthrough Strategies and Solutions, whose research and analysis, conducted with Obama polling firm Harstad Strategic Research, emphasized the importance of talking about extreme weather and "our kids," and appears to have influenced the White House's messaging shift. "The president continues to embrace American ingenuity," says Taylor of the shift away from "green jobs." "But he's rooting it in a message that the right wing really cannot attack: That all you have to do is look out your kitchen window right now and you can see that our climate is changing."

Notably, all of these necessary elements for Obama’s messaging shift were in place prior to Superstorm Sandy. That event just put it over the top, accompanied by multiple exclamation points. A new climate message was born, impelled by reality itself. Obama then chose his moment and delivered a climate speech for the ages.

In other words, the biggest factor behind Obama’s messaging shift on climate was…the climate. It made itself manifest in our weather, in our extremes, in our fires and hurricanes and droughts. Inevitably, people noticed—all the way up to the president.

"Back under Clinton, the president had to talk about climate change in the future tense," observes Paul Bledsoe, a senior fellow on energy and climate at the German Marshall Fund and former Clinton White House climate aide. "'This is going to happen, that is going to happen.' And now, Obama can talk about climate change impacts very much in the present tense.

"And that's all the difference in the world."

The coal industry is worried about environmental threats. Not threats like climate change, superstorms, or wildfires. Threats posed by environmentalists.

In May, the American Coal Council—an industry group whose membership includes the biggest coal producers and consumers in the US—hosted a webinar called "What Environmental Activists Are Planning for Coal in 2013." As the invitation put it, "Using social media and community organization tactics, these groups are savvy, motivated and may be off your radar." The industry has begun to refer to this kind of strategy as a "war on coal" that aims to stop pollution from coal-fired power plants.

Meredith Xcelerated Marketing, a New York-based marketing firm that works with businesses like Kraft Foods, Coca-Cola, and Bank of America, put together the presentation on the "environmental threats" posed by groups like, Sierra Club, and Organizing for America (the activist group spun off from Obama's election campaign). Mother Jones obtained a copy of their slideshow. Using newspaper headlines and promotional materials from environmental groups, MXM's presentation points out all the ways environmental activists have found success in taking on coal.

One slide points out the "strength in the environmental narrative" and lists headlines from stories on the decline of coal and the rise of renewables.

The next slide notes enviros' "ability to drive national attention." Another slide notes that recent efforts to get universities to divest from fossil fuels are "a potent form of publicity."


Ross Parman, who put the presentation together, told Mother Jones by email that MXM doesn't do work for ACC; he just put this presentation together for the council. "I was asked to pull together this really top-level overview of some of the messaging and specific campaigns that have targeted the coal industry," said Parman. "The presentation wasn't intended to focus on environmental activists or messaging about climate change, just the campaigns and messages from 10,000 feet."

What's interesting about this is that it shows that anti-coal activists are winning—and that the coal industry is worried. The industry has used the allegation that government regulators and environmentalists are waging a "war on coal" to fight off any and all attempts to curb emissions from coal-fired power plants. But it's not working.

Luke Popovich, the vice president for communications at the National Mining Association, penned an op-ed in the industry magazine Coal Age on a recent court decision upholding the EPA's regulatory authority on Clean Water Act permits that noted as much. "Anyway, 'war on coal' never resonated with much conviction among ordinary Americans," he wrote. "For them, the EPA keeps the air and water clean, their kids safe."

But Popovich's piece, as Ken Ward at the Charleston Gazette pointed out last month, goes on to call for a doubling down on the rhetorical strategy.

And then, when President Obama announced his climate plan last week, the industry and its allies in Congress, launched into the "war on coal" cries once again. I guess some people never learn.

Ivory poachers may have finally met their match: forensic science. A study just published by PNAS describes a carbon-dating technique making it possible to determine the age of elephant tusks—and thus whether a particular piece of ivory has been acquired illegally. 

The method involves measuring the radiocarbona radioactive isotope of carbon—at the base of a tusk to learn when the elephant died. Kevin Uno, the lead author on the study and a postdoctoral researcher at the Lamont-Doherty Earth Observatory, broke down how it all works: "Plants absorb carbon dioxide and it gets locked into the leaf. Then some elephant walks by, eats that plant, and then builds its tissue, either tusk or hair, from the plant it ate."

As Uno explained, new tissue forms every day in the elephant's tusk as it eats, with the base containing the newest tissue. Because the carbon absorbed by plants contains radiocarbon from the atmosphere, researchers can match the radiocarbon level in the tissue. But the key to the technique is something that scientists call the "bomb curve," the period between 1952 to 1962 during which radiocarbon nearly doubled because of nuclear weapons testing. After the test ban treaty went into effect in 1963, the concentration of radiocarbon in the atmosphere has been diluted at a steady rate. Researchers used samples from primate hair, hippopotamus canines, elephant tusks, and an oryx horn to test their technique. 

Demand for ivory in China has increased dramatically because of the country's economic boom.

As the study explains, "Bomb-curve dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue." Because elephants are threatened by extinction, CITES declared a ban on the trade of tusks from African elephants in 1989 and those from Asian elephants in 1975. 

CITES estimates that elephant poaching is at its highest level since 2002 (PDF). According to the International Union for the Conservation of Nature, only 423,000 African elephants remain—nearly 50,000 less than there were in 2007. In 2011, 86,000 pounds of illegal ivory were seized worldwide, with China being the largest importer and the US coming in second. Demand in China, where ivory is often used in both art and religious sculpture, has recently increased as a result of the country's economic boom. Tusks have become a lucrative "conflict resource" in battle zones in Africa, like Uganda, South Sudan, and the Democratic Republic of Congo. 

Last year at a Senate Committee on Foreign Relations hearing, then committee chairman John Kerry described how poaching has become an organized crime. "The ivory trade stretches from the African savannah to the Asian market place, and the United Nations Office on Drugs and Crime ranks it as a significant form of transnational organized crime. Multiple reports describe armed men coming across the border from Sudan into the Central African Republic or from Somalia into Kenya to kill elephants and smuggle out the ivory."

The loss of elephants is particularly problematic because they are a "keystone species in the ecosystem," says George Wittemyer, an assistant professor at Colorado State University and co-authored the study. "They are the driver of the balance between grass and woodland in the savannah, and they have impacts on water distribution for other species. What we've seen in some areas which have lost their elephants is a domination of woody vegetation and the elimination of all grazing species."

The researchers plan to use their method in tandem with a DNA tool developed in 2004 by the University of Washington's Center for Conservation Biology. Sam Wasser, the center's director, analyzed the DNA in elephant dung and created a map of African elephant populations based on his findings, which allows investigators to determine where ivory comes from.

By using the radiocarbon dating technique with the DNA tool, researchers could pinpoint "poaching hotspots" and notify countries to direct resources to those areas. In addition to being relatively inexpensive—carbon-dating a tusk costs approximately $500 and the DNA analysis costs about $100 plus labor—the process is fairly quick, taking one to two weeks. 

Beyond the benefits this could have for tracking illegal ivory trade, the technique has more far-reaching scientific implications as well. 

"Part of my research involves using teeth and tusks as a tape recording of the environment in which the animal lived," says Uno. "It's a useful tool for looking at ecosystem change or tracking climate change in a particular region. We found thirty years of life in an elephant tusk we looked at," he continues. "It doesn't get any better than that."

Yarnell Hill Fire with Firefighters

In the wake of the tragic news that 19 heroic members of an elite "Hotshot" firefighting team were killed in Arizona, there's been renewed discussion about climate change and how it is worsening wildfires. In particular, there's considerable evidence that western fire seasons are getting longer and more destructive, and that this is tied to more extreme heat and drought.

But does the same dynamic make the act of wildland firefighting riskier? There are reasons to suspect that it does.

Nick Sundt is a former western smoke jumper—a firefighter who literally parachutes in to combat blazes, often in remote locations, acting as a kind of first line of defense. He fought fires from Alaska to New Mexico for a decade during the 1980s. Now, he's the communications director for climate change at the World Wildlife Fund. No wonder that he has focused much of his attention of late on how Western fires, and conditions for his fellow firefighters, are getting worse.

Federal and state "HotShot" crews, explains Sundt, are composed of highly trained specialists who are at the top of their physical game—for instance, they have to be able to hike three miles in 45 minutes carrying a 45 pound pack. They are dispatched to fight fires that grow beyond the capacity of first arrivers—such as smokejumpers—to combat. What follows is often intense, dangerous labor for 16 hours at a time or even longer.

As Sundt explains, members of these teams are "arguably the most physically fit and well organized crews of firefighters" that governments have at their disposal. But that doesn't mean that they're ready for every situation.

In the case of the Arizona team, the emergency shelters that Hotshots take with them—to protect from heat, and preserve oxygen—appear to have been insufficient, for unknown reasons. Such shelters, it is important to note, are not able to resist direct exposure to flames.

With fire dynamics changing and overall temperatures rising, meanwhile, even the best prepared firefighters may be facing greater risks.

The first such risk involves a well-documented increase in average temperatures in fire-prone regions—punctuated by heat waves of the sort now underway in the West. Extreme heat is of course a physical danger in and of itself (for a video on heat risks to firefighters, see here or below), as well as a major stressor for firefighters who are often operating in intense conditions, with little sleep for days on end—all the while wearing heavy equipment and carrying gear, tools, and water. "I've fought fire in the Mojave Desert in 100 plus temperatures, and you grab a drink, it's like drinking hot tea out of your canteen," says Sundt.

What's more, these hotter temperatures make it harder for crews to sleep. Firefighters often work at night, according to Sundt, when weather conditions are more favorable. That means they have to go back to camp and try to sleep during the hottest hours of the day. Meanwhile, even the night shifts aren't as cool as they used to be. The 'C-N-A Crew' would help us do our work at night," Sundt says—explaining that "C-N-A" stands for "cool night air." But nighttime average temperatures are also rising. That means fires are more likely to be active, and firefighters less likely to get a reprieve.

The other new risk to firefighters? Simply that they're tangling with a different beast than they may be used to. "Many firefighters have commented that they are facing more extreme fire behavior than they have witnessed in their lifetimes," remarked Dr. Michael Medler, a former wildland firefighter and now a professor at Western Washington University, in 2007 congressional testimony. If fires are behaving in different ways than expected—if they're larger, if they're unusually severe—that's an added risk. Longer fire seasons also expose more firefighters to more potential hazards in general. (For more on how wildfires are changing see our explainer here.)

That's not to say that climate change is the only factor making wildfires worse or seemingly more destructive. Increased development in fire prone areas is also at play, as are questionable past "fire suppression" practices. But we can't ignore the climate factor. 

"Heat stresses firefighters like anyone else," says Sundt.

The Yarnell Hill fire rages north of Phoenix.

UPDATE, Monday, July 1, 5:00 p.m. EDT: The emergency shelters used by wildland firefighters have a good track record for preventing deaths, but are rendered useless if put in direct contact with fire, a firefighting equipment specialist for the US Forest Service said.

Tony Petrilli said the most up-to-date version of the shelter, in use since 2003, has been deployed 116 times with only two fatalities. Essentially an aluminum sleeping bag coated with silica, the shelter is designed to capture breathable air and keep out heat. But if a fire burns directly over the bag, it can fall apart, Petrilli said; firefighters are trained to look for a spot to roll the bag out that will be away from direct flames, but in the type of drastic situation where the bag is needed there is no guarantee such a spot will be available, and emergency shelter sites are not predetermined, he said.

The standard-issue emergency fire shelter, from a Forest Service handbook on their use. Courtesy US Forest Service

"The best instructions we can give is that it's up to you to find the best deployment site," he said.

Petrilli declined to comment on the effectiveness of these shelters in yesterday's deaths, citing the ongoing investigation. It's unclear at this stage whether all the firefighters who lost their lives were able to make it into their shelters in time, or whether the shelters could have failed.

Heat will eventually seep into the bag if left near a fire for more than a few minutes, Petrilli said. The human body can withstand temperatures of up to 300 degrees F for a short period of time, but temperatures within wildfires can easily exceed 1,000 degrees.

"Anything wrapped in foil that gets exposed to heat, is going to heat up," he said. "It's only a matter of time."

19 wildland firefighters were killed in Arizona yesterday fighting the Yarnell Hill Fire near Prescott, a forested town in the mountains north of Phoenix.

The group, part of the City of Prescott's Granite Mountain Hotshot crew, was trying to escape from the worsening blaze to a predesignated safety zone when the fire, driven by high winds, suddenly changed direction and overwhelmed the team, a spokesman for the Prescott Fire Department, Wade Ward, told Mother Jones.

"It happened too fast," Ward said. "It's nothing you can outrun."

Ward said at the time of the deaths, the massive fire was speeding through the forest at up to a mile a minute, with flames up to 100 feet high. One member of the crew survived, who had gone to relocate the group's vehicle when the flames swept in.

The incident took the lives of the most firefighters since 9/11, when 341 firefighters were killed, according to the National Fire Protection Association, and the most wildfire fighter deaths since the 1933 Griffith Park fire in California, which killed 86. Until Sunday, Arizona had lost only 22 firefighters to wildfires since 1955, far fewer than Colorado or California, according to federal data. Arizona, like much of the Southwest, is in the midst of an ongoing drought, one of the affects of climate change scientists believe is likely to worsen wildfires into the future.

If you're one of 142 million Americans heading to the outdoors this year, there's a good chance you'll run into one of at least 250,000 rivers in the country. Much of the nation's 3.5 million miles of rivers and streams provide drinking water, electric power, and critical habitat for fish and wildlife throughout. If you were to connect all the rivers in the United States into one long cord, it would wrap around the entire country 175 times. But as a recent assessment by the Environmental Protection Agency points out, we've done a pretty bad job of preserving the quality of these waters: In March, the EPA estimated that more than half of the nation's waterways are in "poor condition for aquatic life."

Back in the 1960s, after recognizing the toll that decades of damming, developing, and diverting had taken on America's rivers, Congress passed the Wild and Scenic Rivers Act in 1968 to preserve rivers with "outstanding natural, cultural, and recreational values in a free-flowing condition." Unfortunately, only a sliver of US rivers—0.25 percent—have earned federal protection since the act passed.

In the interactive map below, we highlight 21 rivers that, based on the conservation group American Rivers' reports in 2012 and 2013, are under the most duress (or soon will be) from extended droughts, flooding, agriculture, or severe pollution from nearby industrial activity. Find out which rivers are endangered by hovering over them (in orange). Jump down to the list below to read about what's threatening the rivers. For fun, we also mapped every river and stream recorded by the National Oceanic and Atmospheric Administration. It was too beautiful not to.

Endangered Rivers, 2012-13