TIME climate change

The End of Spring in a Warming World

Climate change affects flowering
Climate change is altering the timing and duration of wildflower blooming Photo by Auscape/UIG via Getty Images

As the planet warms, wildflower blooming and other signs of spring are moving earlier and earlier—altering our idea of what the seasons mean, and creating an unpredictable ripple effect

The first day of spring is finally here, even if it doesn’t feel that way in much of the still frigid East. Of course, the official beginning of spring has less to do with the weather than it does with Earth’s orbit around the sun—the vernal equinox is the day when the tilt of the planet’s axis is inclined neither toward nor away from the sun. (This also happens during the autumnal equinox at the beginning of fall, and of course the dates are reversed for the Southern Hemisphere.) Wherever you are in the world on Mar. 20, it’s all equinox.

But while the calendar stays the same, the seasons seem to be changing. As the planet warms, spring has been springing earlier. A 2009 study in Nature estimated that spring now comes about 1.7 days earlier than it did during the first half of the 20th century. Decades of data collected around Henry David Thoreau’s Walden Pond and Aldo Leopold’s plot of land in Wisconsin indicates that spring flowers have been blooming earlier and earlier in the year, responding to warmer temperatures. And a study published this week in the Proceedings of the National Academy of Sciences (PNAS) that used 39 years of data concludes that wildflowers in the Colorado Rocky Mountains are blooming weeks earlier than they once did and producing their last blooms later. The bloom season, which used to run from late May to early September, now lasts from late April to late September, some 35 days longer.

An earlier spring, a longer blooming season—are these bad things? A lot of climate change skeptics don’t think so:

I can sympathize—after the winter we’ve had in the East, an earlier and longer spring sounds ideal. But the fact that warming seems to be changing the timing of the seasons should concern us, as any phenologist could tell you. Phenology is the study of periodic animal and plant lifecycles, and looks at how the regular variations in the climate that we call seasons affect life. It’s a rich subject area because nearly every form of life runs on recurring cycles governed by the external cues of the environment. This is how Leopold, one of the foremost conservationists in American history and a keen observer of the seasons, put it:

Many of the events of the annual cycle recur year after year in a regular order. A year-to-year record of this order is a record of the rates at which solar energy flows to and through living things. They are the arteries of the land. By tracing their response to the sun, phenology may eventually shed some light on that ultimate enigma, the land’s inner workings.

Take that wildflower study I cite above. Paul CaraDonna, a graduate student at the University of Arizona in Tucson and the lead author of the study, was drawn to the research in part because of his interest in the native bees and other pollinators in the Rocky Mountain Biological Laboratory, 9,500-ft. above sea level near Crested Butte, Colo. Bees depend on flowers for nutrition, so when the bloom season shifts, it’s going to affect the bees. Despite the longer blooming season, plants aren’t producing more flowers. With the same number of flowers blooming over a longer period of time, bees could face a situation where there are fewer in bloom at any given time. “The competition can go up between pollinators for these resources because there’s going to be lesser availability over a greater period of time,” says CaraDonna. And if bees experience repeated population loss, that can in turn impact the very plants that depend on the insects for pollination.

A earlier blooming season can also place wildflowers in danger if they’re hit by a late frost. The meadows the team studies can experience frosts as late as mid-June. “If the snow melts in mid-April, the flowers can have a month and a half before they get zapped by frost in a fragile state,” says CaraDonna. “If you rely on the flowers and they get hit that way, you’ll have no food.” That’s precisely what happened in 2012, when a frost in mid-May wiped out a huge number of flowers that had bloomed early in the season.

Change the timing of spring, and there’s no telling what can happen—although as Amy Iler, another co-author on the study, points out: “It would be very surprising if everything turns out perfectly fine.” Iler and her colleagues are only beginning to piece together how a shifting blooming season will change the environment of the Rocky Mountain meadows—and it will be even more difficult for ecologists to predict the response elsewhere, in places that lack 39 years of minutely recorded data. (The research was begun in 1974 by David Inoyue, a biologist now at the University of Maryland, and over the years Inoyue and his collaborators have counted more than 2 million separate flowers.) The land is still “an enigma,” as Leopold put it, but the X factor of climate change will only make the mystery of the natural world that much more complex. As we add more and more greenhouse gases into the atmosphere, we’re putting ourselves on the path towards an ever more uncertain future, one where even the seasons themselves become unmoored from the calendar.

But if nature’s response to the phenological changes of global warming still remain to be fully discovered, our emotional response is already being felt, as the novelist Zadie Smith wrote recently in the New York Review of Books:

There is the scientific and ideological language for what is happening to the weather, but there are hardly any intimate words. Is that surprising? People in mourning tend to use euphemism; likewise the guilty and ashamed. The most melancholy of all the euphemisms: “The new normal.” “It’s the new normal,” I think, as a beloved pear tree, half-drowned, loses its grip on the earth and falls over. The train line to Cornwall washes away—the new normal. We can’t even say the word “abnormal” to each other out loud: it reminds us of what came before. Better to forget what once was normal, the way season followed season, with a temperate charm only the poets appreciated.

Smith isn’t quite right—as spring becomes a moving target, there is no normal any longer, new or old. March 20 will remain the equinox. The rest remains to be seen.

TIME climate science

Scientists Sound the Alarm on Global Warming, But Americans Sleep In

Climate change impacts Arctic ice
Rapid loss of Arctic sea ice is one of many risks of unchecked climate change Photo by Joe Raedle/Getty Images

A new report from the country's preeminent scientific body warns of the danger of unchecked global warming

Gallup released the results of a new poll on Americans’ opinions about climate change earlier this month. For those concerned about global warming, the data was not promising. On one hand, about two-thirds of Americans believed that global warming is happening or will happen during their lifetime—which, incidentally, happens to be the correct answer. But only about 36% of Americans said they believe that global warming will pose a “serious threat to their way of life” during their lifetimes. Climate change is also very low on the priority list for most Americans—51% of those surveyed said they worry about climate change very little or not at all. And 42% of Americans said they believe the seriousness of global warming is “generally exaggerated” in the news.

This is just one survey, and there is no shortage of methodological problems with most opinion polls. But the results make a sobering backdrop to yet another new report from a scientific organization that practically screams about the imminent dangers of global warming. This one is from the American Association for the Advancement of Science (AAAS), the preeminent scientific organization in the U.S., and it focuses starkly on the risks posed by unchecked climate change—both the more modest dangers that scientists are virtually certain about, and the catastrophic threats that might not materialize, but which would wreck havoc on the planet if they do:

The evidence is overwhelming: levels of greenhouse gases in the atmosphere are rising. Temperatures are going up. Springs are arriving earlier. Ice sheets are melting. Sea level is rising. The patterns of rainfall and drought are changing. Heat waves are getting worse as is extreme precipitation. The oceans are acidifying. The science linking human activities to climate change is analogous to the science linking smoking to lung and cardiovascular diseases.

That last bit is important. It took decades to establish a firm scientific connection between smoking and cancer—and it was an effort that tobacco companies fought every inch of the way, using doubt-stoking tactics that would later be taken up by the fossil fuel industry as it tried to make the public skeptical about man-made climate change. No doctor can tell you exactly how much smoking increases your risk of cancer and cardiovascular disease. But the science is strong enough—and lung cancer is a scary enough danger—that smoking rates have fallen drastically over the past few decades, reaching an all-time low this year.

That’s what the AAAS is trying to do with this report—cement the connection between man-made climate change and environmental and social disaster, to the point where the public will support steps to reduce carbon emissions. “This project is to make clear to the public and to policymakers what we know,” said Alan Lensher, the head of the AAAS. “The earth is warming and human behavior is heavily responsible for it. We need to do something now.”

Of course, this message has been repeated over and over again in scores of similar scientific reports, all sounding the same warning notes. Later this month the Intergovernmental Panel on Climate Change (IPCC) will come out with the next chapter of its latest assessment on climate science—this time focusing on the expected impacts of global warming—and you can expect a similar message. But as Justin Gillis of the New York Times writes, one difference with the AAAS report is its lead author, Mario Molina, who was part of a group of researchers in the 1970s who found a connection between chlorofluorocarbons (CFCs) and ozone depletion:

At a Fort Lauderdale, Fla., conference in 1972, a California scientist namedF. Sherwood Rowland learned that [CFCs] were accumulating in the air. What, he wondered, would happen to them? He eventually put a young researcher in his laboratory, Dr. Molina, onto the question.

To their own shock, the team figured out that the chemicals would break down the ozone layer, a blanket of gas high above the ground that protects the world from devastating levels of ultraviolet radiation. As the scientific evidence of a risk accumulated, the public demanded action — and eventually got it, in the form of a treaty phasing out the compounds.

That’s what climate campaigners would like to see with global warming: The science is established, it shifts public opinion, which then drives policy change to solve the problem. But climate change is a far more complex problem than ozone depletion, and carbon is far more central to the global economy that CFCs ever were. (And as Roger Pielke Jr. pointed out in this 2012 piece for the Breakthrough Institute, the story of science and the ozone layer is a little more complicated than it seems—solid technological alternatives to CFCs were developed well before talk of a global ban gained steam.) It’s hard to see one more blue-ribbon report moving public opinion on climate change, even one that carries the imprimatur of the AAAS.

Which is no reason not to try. (Although it may help to review the large body of social science around climate change inaction.) If you write about global warming day in and day out like I do, it’s easy to become immured to all the warnings, all the dire predictions. But the reality is that we are very much in the early stages of what the scientist Ken Caldeira has called “the great climate experiment,” with the planet is projected to warm faster over the next century than it has in 65 million years. Right now the CO2 concentration in the planet’s atmosphere has passed 400 ppm—it was 280 ppm before we began mass burning fossil fuels in the 19th century—and it’s likely to stay that high for the rest of the month, and eventually, forever.

It’s possible that we may get lucky and escape the most catastrophic risks posed by climate change—just as it’s possible you can smoke a pack a day and live until 90. It’s just not likely, and every day that passes without any real effort to curb carbon emissions makes disaster more certain. Sooner or later.

TIME Agriculture

Climate Change Could Cause the Next Great Famine

Climate change impacts crop yields
A warmer climate could reduce the yield of staple crops like maize Photo by John Moore/Getty Images

A new study finds that as the planet warms, yields for important staple crops like wheat could decline sharply.

It’s St. Patrick’s Day, which means the 100 million or so people of Irish descent around the world get the opportunity to celebrate their heritage with song, food and increasingly controversial parades. The sheer size of the Irish diaspora is what has made St. Patrick’s Day an international event—after all, there are only 6.4 million Irish people in Ireland. But it’s also a reflection of the waves of emigration that marked Ireland’s history until recently—emigration that was fueled in part by the great famine of the 1840s. Triggered by a disease that wiped out the potato, Ireland’s staple crop, the Great Famine—an Gorta Mor in Irish—led to the death of a million people and caused another million to flee the country. Without the potato blight, that Irish diaspora—and your local St. Patrick’s Day festivities—might be significantly smaller.

The Great Famine is a reminder of the way failures in agriculture can drive lasting historical change—while leading to immense human suffering. That’s a useful backdrop of a new analysis on the impact global warming will have on crop yields, just published in Nature Climate Change. The news isn’t good: the research, based on a new set of data created by the combination of 1,700 previously published studies, found that global warming of only 2º C (3.6º F) will likely reduce yields of staple crops like rice and maize as early as the 2030s. And as the globe keeps warming, crop yields will keep shriveling unless drastic steps are taken to adapt to a changing climate. As Andy Challinor, a professor of climate impacts at the University of Leeds and the lead author of the study, put it in a statement:

Our research shows that crop yields will be negatively affected by climate change much earlier than expected…Furthermore, the impact of climate change on crops will vary both from year-to-year and from place-to-place—with the variability becoming greater as the weather becomes increasingly erratic.

The effect that warming will have on crop yields is one of the most vital areas of climate research—and one of the most vexing. Warming will have different impacts on different kinds of crops in different parts of the world. Warmer temperatures—and the higher levels of carbon dioxide that come with them—may enhance yields in the short-term, but as the climate gets hotter and hotter, crops could wilt, especially in the tropics. Changes in precipitation—both prolonged droughts and bigger storms—will hit farmers hard as well. And with a 842 million hungry people around the world—and another 2 billion or so who will need to be fed by mid-century as global population grows—accurately nailing down the impact climate change will have on crop yields could make the difference between life and death for vast numbers of people.

The last assessment from the Intergovernmental Panel on Climate Change (IPCC) from 2007 found that temperate regions like Europe would be able to deal with moderate, 2º C warming without much of an impact on crop yields. But the newer research used in the Nature Climate Change study indicates that that conclusion might have been too optimistic, especially as the climate gets warmer and warmer towards the century’s end. Farmers in the tropics will have it particularly difficult—yields from maize could drop by 20% or more if temperatures increase by more than 3º C (5.4º F). And those reductions in yield could hide much bigger year-to-year swings, if the weather gets more extreme. “Climate change means a less predictable harvest, with different countries winning and losing in different years,” said Challinor. “The overall picture remains negative.”

We should have a better sense of where climate research stands on crop impacts later this month, when the IPCC comes out with the next chapter in its newest climate science assessment. And farmers—especially in developed nations—can and likely will adapt to what global warming will throw at them, whether by changing crop planting schedules, shifting to more efficient irrigation or taking advantage of biotechnology. But there’s no guarantee that poor farmers—who already produce less per acre—will be able to keep up. The Great Famine was triggered by the potato blight, but it was intensified by cruel policy on the part of Ireland’s British masters, who ensured that rich stores of grain and livestock were exported out of the country even as Irish citizens starved to death in the streets. As a warming climate makes the difficult task of keeping the world fed even tougher, we can only hope that wiser policy prevents the next famine.

TIME big data

Google’s Flu Project Shows the Failings of Big Data

Google flu trends
GEORGES GOBET/AFP/Getty Images

A new study shows that using big data to predict the future isn't as easy as it looks—and that raises questions about how Internet companies gather and use information

Big data: as buzzwords go, it’s inescapable. Gigantic corporations like SAS and IBM tout their big data analytics, while experts promise that big data—our exponentially growing ability to collect and analyze information about anything at all—will transform everything from business to sports to cooking. Big data was—no surprise—one of the major themes coming out of this month’s SXSW Interactive conference. It’s inescapable.

One of the most conspicuous examples of big data in action is Google’s data-aggregating tool Google Flu Trends (GFT). The program is designed to provide real-time monitoring of flu cases around the world based on Google searches that match terms for flu-related activity. Here’s how Google explains it:

We have found a close relationship between how many people search for flu-related topics and how many people actually have flu symptoms. Of course, not every person who searches for “flu” is actually sick, but a pattern emerges when all the flu-related search queries are added together. We compared our query counts with traditional flu surveillance systems and found that many search queries tend to be popular exactly when flu season is happening. By counting how often we see these search queries, we can estimate how much flu is circulating in different countries and regions around the world.

Seems like a perfect use of the 500 million plus Google searches made each day. There’s a reason GFT became the symbol of big data in action, in books like Kenneth Cukier and Viktor Mayer-Schonberger’s Big Data: A Revolution That Will Transform How We Live, Work and Think. But there’s just one problem: as a new article in Science shows, when you compare its results to the real world, GFT doesn’t really work.

GFT overestimated the prevalence of flu in the 2012-2013 and 2011-2012 seasons by more than 50%. From August 2011 to September 2013, GFT over-predicted the prevalence of the flu in 100 out 108 weeks. During the peak flu season last winter, GFT would have had us believe that 11% of the U.S. had influenza, nearly double the CDC numbers of 6%. If you wanted to project current flu prevalence, you would have done much better basing your models off of 3-week-old data on cases from the CDC than you would have been using GFT’s sophisticated big data methods. “It’s a Dewey beats Truman moment for big data,” says David Lazer, a professor of computer science and politics at Northeastern University and one of the authors of the Science article.

Just as the editors of the Chicago Tribune believed it could predict the winner of the close 1948 Presidential election—they were wrong—Google believed that its big data methods alone were capable of producing a more accurate picture of real-time flu trends than old methods of prediction from past data. That’s a form of “automated arrogance,” or big data hubris, and it can be seen in a lot of the hype around big data today. Just because companies like Google can amass an astounding amount of information about the world doesn’t mean they’re always capable of processing that information to produce an accurate picture of what’s going on—especially if turns out they’re gathering the wrong information. Not only did the search terms picked by GFT often not reflect incidences of actual illness—thus repeatedly overestimating just how sick the American public was—it also completely missed unexpected events like the nonseasonal 2009 H1N1-A flu pandemic. “A number of associations in the model were really problematic,” says Lazer. “It was doomed to fail.”

Nor did help that GFT was dependent on Google’s top-secret and always changing search algorithm. Google modifies its search algorithm to provide more accurate results, but also to increase advertising revenue. Recommended searches, based on what other users have searched, can throw off the results for flu trends. While GFT assumes that the relative search volume for different flu terms is based in reality—the more of us are sick, the more of us will search for info about flu as we sniffle above our keyboards—in fact Google itself alters search behavior through that ever-shifting algorithim. If the data isn’t reflecting the world, how can it predict what will happen?

GFT and other big data methods can be useful, but only if they’re paired with what the Science researchers call “small data”—traditional forms of information collection. Put the two together, and you can get an excellent model of the world as it actually is. Of course, if big data is really just one tool of many, not an all-purpose path to omniscience, that would puncture the hype just a bit. You won’t get a SXSW panel with that kind of modesty.

A bigger concern, though, is that much of the data being gathered in “big data”—and the formulas used to analyze it—is controlled by private companies that can be positively opaque. Google has never made the search terms used in GFT public, and there’s no way for researchers to replicate how GFT works. There’s Google Correlate, which allows anyone to find search patterns that purport to map real-life trends, but as the Science researchers wryly note: “Clicking the link titled ‘match the pattern of actual flu actvity (this is how we built Google Flu Trends!)’ will not, ironically, produce a replication of the GFT search terms.” Even in the academic papers on GFT written by Google researchers, there’s no clear contact information, other than a generic Google email address. (Academic papers almost always contain direct contact information for lead authors.)

At its best, science is an open, cooperative and cumulative effort. If companies like Google keep their big data to themselves, they’ll miss out on the chance to improve their models, and make big data worthy of the hype. “To harness the research community, they need to be more transparent,” says Lazer. “The models for collaboration around big data haven’t been built.” It’s scary enough to think that private companies are gathering endless amounts of data on us. It’d be even worse if the conclusions they reach from that data aren’t even right.

TIME climate change

A Tale of Two Winters

Winter ice on Lake Michigan on Chicago
The winter was brutal in Midwestern cities like Chicago Scott Olson/Getty Images

If you lived east of the Rockies, you froze this winter. But the other side of the country experienced unusual warmth—and sometimes record-high temperatures

As I write this in New York, it’s 25 degrees Fahrenheit (-3.9 Celsius)—about 21 F degrees below normal for Mar. 13—and frankly, we’re all sick of this. For much of the eastern half of the country, 2013-14 has been the winter that will never end. And now the numbers are in from the National Oceanic and Atmospheric Administration (NOAA), and we’re mostly right: It’s been very cold. But probably not as cold as you think.

The average temperature for the continental U.S. from December to February was 31.3 F (-0.4 C), 1.0 F (0.55 C) below the 20th century norm. That’s hardly record-breaking—it’s only the 34th coldest winter in recorded U.S. history—but it’s a lot colder than last winter, where the average temperature was 34.3 F (1.3 C), which helps explain why it felt so frigid. Even so, the continental U.S. experienced a colder winter as recently as 2009-2010, well before anyone had heard of the term “polar vortex,” and back when only hurricanes—not snowstorms—were given names.

How cold you were this winter depended largely on where you were in the U.S. If you lived east of the Rockies—home to significantly more than half the U.S. population and sometimes, it seems, virtually all the U.S. media—you experienced below-average temperatures. Midwesterners had it particularly bad—most of the area north of the Ohio River was 7 to 15 F (4 to 8 C) below normal, which helps explain why at their peak in early March 91% of the Great Lakes were frozen over. It was nasty for the Northeast as well, where temperatures were largely cooler than normal, especially in the western regions near the lakes (pity the citizens of Erie, Pennsylvania, where temperatures were nearly 5 F, or 2.75 C, below normal for the winter.) From Washington D.C. to Caribou, Maine, it seems that not a single town in the Northeast had above-normal temperatures this winter.

That wasn’t the case in the West, though. California—already in an incredibly severe drought—had the warmest winter on record, with average temperatures of 48.0 F (8.9 C), some 4.4 F (2.2 C) above the 20th century average and nearly 1 F (0.55 C) hotter than the previous warmest winter, in 1980-81. That’s a reminder of just how big the U.S. is, and how variable weather can be—which brings us to climate change. Scientists are going to have fun figuring out just what was behind phenomena like the polar vortex (one theory is that higher temperatures in the Arctic could impact the jet stream, allowing colder Canadian air to sweep down to the East). But a nasty winter in New York City no more disproves climate change than an all-time hot winter in California clinches the case for global warming. Climate change is a global phenomenon and a long-term one, which is why icy temperatures along the East Coast in January are a lot less important than the fact that the global land and ocean surface average temperature for January was 1.17 F (0.65 C) above the 20th century norm, which made it the fourth-warmest January on record globally.

Barring even weirder weather, winter should finally be giving way to spring even in the coldest states in the U.S.—finally. But with scientists warning of a possible El Nino later this year—which usually brings hotter temperatures—we may end up looking back on the polar vortex with fondness as the dog days of August drag on. Maybe.

TIME energy

Frack, Rattle and Roll: Did Hydraulic Fracturing Play a Role in Ohio Quakes?

Fracking and Ohio quakes
Fracking wells may be triggering seismic activity MLADEN ANTONOV/AFP/Getty Images

Ohio officials shut down several wells after a pair of earthquakes. How much of a role does hydraulic fracturing play in the startling rise of quakes in the middle of the U.S.?

The mystery over the possible connection between hydraulic fracturing and earthquakes deepened on Mar. 10, when the Ohio government ordered a halt to operations at seven oil and gas wells near the Pennsylvania border after two quakes occurred earlier that day. While the quakes in Ohio’s Poland Township were too small to cause damage or injuries—they measured in at 2.6 and 3.0 on the Richter scale—the fact that one of the wells was undergoing fracking at the time of the quakes was enough for the Ohio Department of Natural Resources (ODNR) to suspend drilling operations in the area. “The decision was made out of an abundance of caution after analyzing location and magnitude data provided by the U.S. Geological Services” ODNR spokesman Mark Bruce said in an emailed statement.

Other than that, Ohio officials haven’t been saying much about the possible connection of the quakes to fracking operations—and neither has Hilcorp Energy, the Texas-based company operating in the area, which said in a statement that “we are not aware of any evidence to connect our operations to these events.”

It will take more research to know if fracking at those wells directly led to the small quakes, but it’s not impossible. While there is a stronger connection between earthquakes and deep injection wells—where wastewater left over from fracking is disposed of by being piped at high pressures deep underground—there have been a few instances in which the act of fracking itself seems to have made the earth move. (In case you haven’t been paying attention, fracking involves the fracturing of shale rock thousands of feet below the ground, using millions of gallons of water and chemicals, to free up trapped oil and natural gas.) Quakes in British Columbia, England and south-central Oklahoma have been traced back to fracking—and since Ohio officials say there were no disposal wells in the area where the quakes occurred, it’s definitely possible that fracking could have played a role here as well, as retired Columbia University geology professor John Armbruster told the Columbus Dispatch:

It’s an area which (before 2011) had no history of earthquakes. It looks very, very suspicious.

What’s definitely suspicious is the astounding increase in earthquake activity in parts of the central and eastern U.S.—the same areas that have taken part in the fracking boom, as this chart from the USGS shows:

Nearly 450 earthquakes with a magnitude of 3.0 and larger occurred in the region in the four years from 2010-2013, over 100 per year on average, compared to an average rate of 20 earthquakes per year observed from 1970-2000. Last month, Oklahoma was hit by a wave of more than 150 minor earthquakes over the course of a week, including one that had a magnitude of 3.8, and today 10% of the quakes felt in the U.S. occur in the Sooner State. All of this is happening against the backdrop of the fracking revolution. In Ohio, oil production doubled between 2012 and 2013, and natural gas production increased by two and a half times.

The reason fracking itself does not trigger detectable seismic activity all that often is that the forces involved are relatively weak, and the fragile shale rock tends to fracture before it can build up much strain—which is, after all, the point of fracking. That doesn’t mean it’s impossible, just that it seems to pose less of a risk that deep injection wells, which involve far greater amounts of liquid and which have been known to trigger quakes since the 1960s. Here’s how the USGS put it:

Wastewater injection increases the underground pore pressure, which may, in effect, lubricate nearby faults thereby weakening them. If the pore pressure increases enough, the weakened fault will slip, releasing stored tectonic stress in the form of an earthquake. Even faults that have not moved in millions of years can be made to slip and cause an earthquake if conditions underground are appropriate.

Fracking has boomed across the country, as this excellent map from the Post Carbon Institute shows:

All the wastewater created by those fracked oil and gas wells has to go somewhere—hence the concurrent boom in disposal wells. Ohio has more than 188 such wells, with more being drilled, in part to take wastewater from Pennsylvania fracking after regulators in that state ordered oil and gas companies to stop dumping waste in streams. And while most of the quakes happening in frackland have been small, there have been some bigger ones, including a 5.7 magnitude quake in Nov. 2011 in Prague, Oklahoma that a USGS study this week linked to a disposal well. “The observation that a human-induced earthquake can trigger a cascade of earthquakes, including a larger one, has important implications for reducing the seismic risk from wastewater injection,” the study’s coauthor, USGS seismologist Elizabeth Cochran, said in a statement.

So induced earthquakes are definitely one more reason to worry about the rapid spread of fracking. But like most of the other concerns—potential groundwater contamination, spills and accidents, stress on small town infrastructure—seismic risk should be manageable with the right regulations. The USGS notes that there are some 30,000 wastewater disposal wells around the country, and “very few” seem to have the potential to cause quakes. Geologists know where fault lines are, and if we listen to them, we should be able to ensure that any new wells, whether drilled to get gas and oil or to store wastewater, are well clear of them. But until we do, don’t expect the shaking to stop.

TIME climate change

How Climate Change Drove the Rise of Genghis Khan

Mongol herdsmen
New research suggests that climate change may have helped the rise of the Mongol empire Evin Krajick—Earth Institute, Columbia University

The Mongol warlord built the world's largest land-based empire. But he couldn't have done it without a change in climate

In the late 1100s, the Mongol tribes were split by dissension, a threat to no one but themselves. By the early decades of the 1200s, the tribes had become a united force that rained havoc on its neighbors, expanding in every direction on a wave of horses. Eventually the Mongols would establish the largest land empire in history, ruling over modern Korea, China, Russia, eastern Europe, southeast Asia, Persia, India and parts of the Middle East. To this day the DNA of the Mongols can be found throughout the territories that once made up their empire.

The difference was Genghis Khan, the warlord who united the tribes and launched them on their wave of unstoppable conquest. But the Mongol Empire wasn’t solely the product of Genghis’s will. As a fascinating new study in the Proceedings of the National Academy of Science (PNAS) demonstrates, the rise of the Mongols may have owed just as much to beneficial changes in the climate that made the grasslands of the Mongol steppes green and verdant, fueling the horses that were the backbone of the empire’s military. Climate change helped make the Mongol Empire possible.

The PNAS study came from research done by the tree-ring scientists Neil Pederson at Columbia University’s Lamont-Doherty Earth Observatory and Amy Hessl at West Virginia University. On a research trip to Mongolia in 2010, Pederson, Hessl and their colleagues discovered a stand of stunted Siberian pine trees in the Khangai Mountains. The trees—some of which were still alive—were ancient, some more than 1,100 years old. Old trees provide a living history book of the climate. During warm, wet years, the trees grow more, and the rings inside the trunk that mark those years are wider. The opposite happens during dry years, when the rings would be narrow.

Counting back to the late 1100s, just before the rise of Genghis Khan, the tree-ring data indicated that the Mongol steppes had been in the grip of an intense drought, one that could have helped drive the years of division among the Mongol tribes as they competed for scarce resources. But the tree-rings showed that the years between 1211 and 1225—a period of time that coincided with the meteoric rise of Genghis Khan, who died in 1227—were marked by unusually heavy rainfall and mild temperatures. It didn’t turn Mongolia’s harsh steppes into Maui, but the warmer climate would have stimulated the growth of the grasslands that fed the Mongols’ vital herds of horses and livestock. Given that each Mongol warrior had five or more horses, the energy represented by that additional grass would have helped fuel their astounding rate of expansion.

As Hessl put it in a statement:

The transition from extreme drought to extreme moisture right then strongly suggests that climate played a role in human events. It wasn’t the only thing, but it must have created the ideal conditions for a charismatic leader to emerge out of the chaos, develop an army and concentrate power. Where it’s arid, unusual moisture creates unusual plant productivity, and that translates into horsepower. Genghis was literally able to ride that wave.

Of course, climate change was hardly the only factor in the Mongols’ wave of conquest. Genghis used that supply of horses to form the greatest cavalry force the world had yet seen, one capable of rolling over opposing militaries. But it seems likely that he benefited from that unusual bout of climate change, just as civilizations ranging from the Anasazi in the American Southwest to the Angkor in Southeast Asia were likely laid low by shifts in climate that led to sudden, devastating drought.

In recent decades Mongolia’s climate has been changing even faster than in the rest of the world, with temperatures in parts of the country rising by as much as 4.5 F over the past 40 years. At the same time, the country has been hit by severe summer droughts followed by a dzud, or a long, harsh winter. The same tree rings that revealed the climactic history of the Mongol empire show that the most recent drought, from 2002 to 2009, compares in its severity only to those dry periods in the late 1100s. The droughts and the dzuds have killed millions of animals and ruined the livelihood of Mongolia’s herders, forcing them to more en masse to the swollen capital of Ulaanbaatar. Climate change is still putting Mongolians on the move—but this time, there’s no end in sight.

TIME climate change

Malaria Climbs Mountains as the Climate Warms

Malaria mosquito
Climate change will expand the range of mosquitoes that transmit malaria UIG/Getty Images

New research says that climate change will cause mosquitos to move into previously bug-free high-altitude territory, bringing the debilitating and often deadly disease with them as they climbs up warming hilly terrain

Malaria is one of the most common—and deadly—infectious diseases in the world, sickening more than 300 million people a year and killing over 600,000 people. But because it’s a mosquito-borne disease—the parasite that causes malaria is passed to human beings by mosquito bites—its range has been limited to warmer tropical areas, the so-called “malaria belt.” And even within tropical countries, altitude matters: the disease is much less common in tropical highlands, where colder temperatures slow down both the mosquito and the development of the parasite within it. It’s not for nothing that 19th century British colonists would build hill stations in malaria-prone countries like India, to escape both heat and disease.

So it’s not surprising either that scientists have been trying to find out for years whether climate change might expand the range of malaria, putting millions of people who live in tropical highlands at risk. Warmer temperatures should mean more malaria, but in recent years the number of cases has actually fallen dramatically, largely because of renewed efforts to fight the disease. But now a new study in Science makes a strong case that as the climate warms, malaria will indeed be on the march, expanding its range to previously safe high-altitude territory, putting even more pressure on prevention campaigns—and if those fail, leading to more deaths.

Researchers from the London School of Hygiene and Tropical Medicine and the University of Michigan sifted through regional records in Ethiopia and Colombia, two tropical countries with highland territory, looking at malaria cases from 1990 to 2005 in Colombia and 1993 to 2005 in Ethiopia. They corrected for other factors that might influence malaria cases—mosquito control programs, for example, which lead to fewer of the insects; and rainfall, which leads to more—and found that the median altitude of malaria cases moved higher in warm years, and lower during cooler yields. All else being equal, as the planet warms, it seems likely that malaria will become more dangerous to more people.

“This is indisputable evidence of a climate effect,” said Mercedes Pascual, a disease ecologist at Michigan and one of authors of the Science paper. “Our findings here underscore the size of the problem and emphasize the need for sustained intervention efforts in these regions, especially in Africa.”

One thing that will make the problem worse is that people who live in tropical highlands tend to be much more vulnerable to malaria parasites to begin with because they’ve never been infected before. In an earlier paper, the Science researchers estimated that a 1° C (1.8° F) temperature increase could lead to an additional 3 million malaria cases in Ethiopian children, assuming control methods weren’t strengthened. And that’s the key point. While global warming will put more people around the world at risk for malaria and other tropical diseases, climate is far from the only factor at work. Developed cities like Singapore are well within the malaria belt, but the disease has been virtually eradicated there thanks to stringent control methods. Malaria was rampant in U.S. states like Georgia as late as the 1920s, but it’s long gone now, eliminated by control efforts that led to the creation of the Centers for Disease Control. And even in Africa, malaria incidences have fallen by 31% since 2000— as the climate has warmed—and globally 3.3 million malaria deaths have been avoided thanks to the work of institutions like the Gates Foundation. Malaria, like many infectious diseases, is first and foremost a problem of development and poverty—and when those are addressed, infections fall.

But by expanding the range of malaria, climate change will make a tough challenge all the more difficult. It’s just one more way carbon can kill.

TIME Solar Power

A Bright Year for Solar in the U.S.—But There Are Clouds on the Horizon

The solar industry is growing in the U.S., but a trade war could change that Don Emmert—AFP/Getty Images

Energy harvested from the Sun was the second-biggest source of new electricity generation capacity in 2013, but there are clouds on the horizon as a trade war between the U.S. and China stands to throw a monkey wrench in the works

You don’t get any brighter than the reflecting mirrors at the just-opened Ivanpah Solar Power Facility, in California‘s Mojave desert. When I visited the project back in May, I was warned not to look directly at the mirrors, lest my eyeballs end up as scorched as some of the birds that have flown through the 1,000° F-plus (538° C) heat generated by the solar towers. The picture is almost as bright for solar as a whole in the U.S. According to statistics released today by the Solar Energy Industries Association, a trade group, demand for solar increased by 41% in 2013, with 4.75 gigawatts of photovoltaic panels installed last year. (1 GW is about enough energy to power 750,000 homes.) That made solar the second-biggest source of new generation power in the U.S. after natural gas, which is still benefiting from the shale revolution. By the end of 2013, there were more than 440,000 operating solar electric systems in the U.S., with more than 12 GW of photovoltaic (PV) and nearly 1 GW of concentrated solar power.

While big utility scale plants like Ivanpah, which harnesses the heat of the sun with concentrated solar mirrors, got most of the headlines, it was small-scale residential systems that drove much of the demand last year. Residential projects increased by 60% over 2012 as the price of installing solar fell and as customers took advantage of leasing options—offered by companies like Solarcity, which I wrote about last year—that allowed them to purchase panels with little money up front. The growth was rolling throughout 2013, with residential installations increasing 33% in the last quarter of 2013, and should continue this year. That financing market is growing: Mosaic, an Oakland-based startup launched by the climate activist Billy Parish, just began offering a home solar loan that allows consumers the chance to borrow the cost of a solar system over 20 years. “2013 offered the U.S. solar market the first real glimpse of its path toward mainstream status,” said Shayle Kann, vice president of GTM Research, which follows the clean tech market.

(MORE: The Power—and Beauty—of Solar Energy)

Bright times for solar, indeed—and that’s just in the U.S. Last year China installed at least 12 gigawatts of solar capacity, at least 50% more than any other country had ever built in a single year. But that’s where things get cloudy. The U.S. solar boom has been fueled in part by cheap solar panels from China, which have helped bring down the cost of solar power—now 15% cheaper than it was in 2012. But those same cheap Chinese panels have hurt domestic manufacturers of solar PV, even as they’ve helped installers like Solarcity. Several domestic solar manufacturers—led by SolarWorld, an American arm of a German company—have complained that the Chinese government is unfairly subsidizing national solar PV manufacturers, which allows them to undercut their American competitors.

In response, the U.S. government agreed in 2012 to impose tariffs of 24 to 36% on Chinese PV panels. But that made little difference—Chinese companies just outsourced much of their production to Taiwan. This year, however, SolarWorld brought a new suit in response, pushing the U.S. to extend those tariffs to Chinese panels made in Taiwan. Last month, the U.S. International Trade Commission said it would move forward with an investigation, and is set to issue a preliminary ruling by the end of March. If those tariffs are indeed extended, you can expect solar power in the U.S. to get more expensive, slowing down growth and hitting installers—who employ far more Americans than U.S. solar manufacturers do—very hard, especially since China has already said it would impose retaliatory tariffs. More expensive panels would likely depress demand for solar in the U.S., hurting installers.

There’s some truth to the argument that China may be intentionally driving down the price of solar panels to allow its companies to dominate the industry. But if so, the strategy hasn’t been that effective—a number of Chinese manufacturers have gone bankrupt, including Suntech, which was until recently the world’s biggest panel maker by volume. The U.S. solar industry is at a tipping point, poised to grow its way out of niche status and potentially change the way Americans think—and more importantly, pay for—energy. It’d be a shame if a 21st century industry gets tripped up by 19th century trade politics.

(MORE: Solar Powered Plane Soars Across the U.S.)

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