HEAT VS. WHEAT 

Humanity is overheating its food, allowing global warming to wither crops and drive up food prices, according to a new study published in the journal Science. Rising temperatures haven't affected the planet evenly — nor have they affected every type of crop — but the spread of extreme heat and severe weather has increasingly scorched wheat and corn in Brazil, China, France, India and Russia, the researchers found, raising food prices around the world. "This is tens of billions of dollars a year in lost [farm] productivity because of warming," says study author and Stanford scientist David Lobell.

Compared with what the world would have produced if temperatures remained at 1980 levels, 30 years of warming have slashed global yields of corn by about 5.5 percent and wheat by about 3.8 percent, according to the report. Russia, India and France saw the largest drops in wheat production relative to what they could have grown under normal conditions, while the largest comparative losses in corn production were seen in China and Brazil. One region that has somehow dodged this trend, however, is North America. While farmers in central and southern Mexico have seen harvests stagnate, those in northern Mexico, the U.S. and Canada have so far been largely untouched by all the extra heat. "It appears as if farmers in North America got a pass on the first round of global warming," Lobell says. "That was surprising, given how fast we see weather has been changing in agricultural areas around the world as a whole." But with temperatures forecast to rise 50 percent faster in the next few decades than they have since 1950, Lobell says U.S. farmers shouldn't feel immune. "Given the relatively small temperature trends in the U.S. Corn Belt, it shouldn't be surprising if complacency or even skepticism about global warming has set in, but this study suggests that would be misguided," he says. "[M]ost explanations suggest that warming in the future is just as likely there as elsewhere in the world."

Because wheat and corn make up such a big chunk of our diet, even a few big crop failures can have far-reaching effects, the researchers point out. Combined with soy and rice, wheat and corn account for 75 percent of all the calories humans eat worldwide, either directly or indirectly through livestock feed. And while soy and rice haven't been as affected by warming, the impacts on wheat and corn have caused a 20 percent spike in global food prices since 1980, the study found. That has helped U.S. farmers, since they haven't suffered the relative declines seen in other countries, but Lobell warns that can't last forever. "It will be interesting to see what happens over the next decade in North America," he says. "But to me the key message is not necessarily the specifics of each country. I think the real take-home message is that climate change is not just about the future, but that it is affecting agriculture now. Accordingly, efforts to adapt agriculture such as by developing more heat- and drought-tolerant crops will have big payoffs, even today."

(Sources: ReutersNew York Times, Washington Post, PhysOrg, Science)

HEAVY METAL THUNDER 

Global emissions of mercury could rise by up to 25 percent in the next nine years if nothing is done to curb them, according to a new report by the Arctic Monitoring and Assessment Program. The toxic heavy metal poses a widespread health threat to polar bears, whales and seals, as well as Arctic human communities who hunt those animals for food, the AMAP report points out, raising the stakes for a region that's already at risk from climate change.

"It is of particular concern that mercury levels are continuing to rise in some Arctic species in large areas of the Arctic," despite recent reductions of mercury emissions in neighboring regions such as Europe, North America and Russia, the report says. Those cutbacks may have been offset by increasing emissions in other parts of the world, namely China, which has become the No. 1 mercury polluter on the planet, AMAP suggests. Chinese mercury emissions now account for roughly half of the worldwide total, helping keep mercury levels high among [skipwords]fish[/skipwords] populations that are eaten by marine mammals like seals, whales and polar bears.  Because mercury "bioaccumulates" — with concentrations increasing as it passes up the food web — it can build up to dangerously high levels in the bodies of top-level predators. In polar bears, for example, high mercury levels can cause a chemical imbalance in the brain that influences all aspects of the animal's behavior, survival and reproduction, the AP reports.

And on top of the threat to polar bears, the prospect of soaring mercury emissions is especially troubling for Inuit communities around the Arctic, whose regular consumption of marine mammals places them at the absolute top of the food web. AMAP urges health authorities to explain these risks to Arctic hunters, but is also cautious about offering too much diet advice, since switching to a Western diet and lifestyle could lead to other health problems. "Because the healthy food choices in local stores are quite expensive, if available at all, it is often more affordable but less nutritious processed foods that are chosen," the report warns. If combined with a more sedentary Western lifestyle that doesn't involve hunting and fishing, "this new diet increases the risks of developing obesity-related diseases, such as diabetes and coronary heart disease," AMAP adds.

(Source: Associated Press, AMAP)

A RIVER RUNS OVER IT 

As record-breaking floodwaters continue to surge down the Mississippi River — spurring large-scale evacuations in Missouri, Arkansas and elsewhere — oystermen in Louisiana are eyeing the situation with familiar despair, the AP reports. That's because, just as their industry is starting to recover from the 2010 Gulf oil spill, the U.S. Army Corps of Engineers' plan to release freshwater into brackish oyster beds is poised to deal them yet another setback. While the influx of floodwaters will relieve pressure on local levees, it's all but certain to kill swaths of oysters, too, since too much freshwater can wreak havoc with shellfish metabolism.

"I'm very concerned because I'm just getting back to work now for the first time since the oil spill," says fourth-generation oysterman Shane Bagala. "Now it looks like something else might be threatening us." On Monday, the Corps plans to open the Bonnet Carre Spillway, which was built some 30 miles northwest of New Orleans following the "Great Flood" of 1927. The spillway redirects river water into Lake Ponchartrain, and on into the rich, brackish fishing and oyster grounds of Lake Borgne and the Mississippi Sound, before ultimately flowing into the Gulf. It has been opened nine times since 1937, the AP reports, most recently during the heavy Mississippi Valley floods of 2008. But the Corps is also considering opening the Morganza Spillway, 35 miles northwest of Baton Rouge, which hasn't been opened since 1973. If that happens, the region's seafood industry could be devastated. "If Morganza opens, I assure you there will be significant [oyster] mortalities," warns Mike Voisin, the owner of a local oyster-processing plant. "It's Mother Nature giving us another blow after what BP did last year," adds Nicholls State University biology professor Earl Melancon Jr. "That's dramatic for these oystermen."

The floods are fueled by months of unusually heavy snow and rain across the central U.S., capped by a wave of historic thunderstorms in recent weeks. The Corps has already blown holes in a Missouri levee to save the town of Cairo, Ill., from floods, sacrificing 130,000 acres of farmland in the process. And as Voisin tells the AP, he understands the Corps' need to protect communities from being flooded, even if it comes at the cost of oysters. "I think it's the right thing to do," he says. "We live in this area, too."

(Sources: Associated Press, CNN)

SPACE JAM 

As the U.S. space shuttle era winds down — Endeavour is now slated to launch next Tuesday, while Atlantis' final flight is set for June 28 — the country's space-exploration industry is already undergoing an identity crisis, USA Today reports. After decades of being painted as a "race" between Americans and Soviets, space travel has evolved into an international pursuit, one that will be led by Russia for at least the next few years. "Can you imagine John Glenn or Alan Shepard speaking Russian? That would have been a bad thing back then," space psychologist David Musson tells USA Today. "Cultural sensitivity and language training are part of the astronaut's job now. All the astronauts know a little Russian. Some of them know a lot."

Thursday marked the 50th anniversary of Shepard's historic flight as the first American in space, a milestone that was marred at the time by the Soviets' launch of cosmonaut Yuri Gagarin a month earlier. But as former astronauts, NASA officials and community leaders gathered in Cape Canaveral, Fla., Thursday to commemorate Shepard's flight, they acknowledged that space travel has been transformed from a bitter international competition to a cooperative scientific industry. "We now move out on an exciting path forward where we will develop the capabilities to take humans to even more destinations in the [skipwords]solar[/skipwords] system," NASA Administrator Charles Bolden said at the ceremony. This means big changes for the vaunted space agency, though, including a dwindling astronaut corps. NASA is no longer accepting applications for new astronauts, USA Today reports, and its corps has already shrunk from about 80 to 60.

Still, the switch to commercial space flight for more routine missions to the International Space Station will free up NASA to work on bigger-picture scientific projects, something that fits with President John F. Kennedy's vision for the space program. Even though he used the 1969 moon-landing goal as a way to beat the Soviet's to a celestial milestone, Kennedy was also an advocate of one day collaborating with the Russians, "and fought hard for it in the last two months of his life," says space-policy expert John Logsdon. Plus, as NASA's astronaut training chief Duane Ross argues, the evolution of space travel won't mean the end of astronauts. "There will still be astronaut jobs to be filled," he says. "Little boys and girls will still want to be astronauts," Musson adds.

(Sources: USA Today, Reuters, Space.com)

THIS DAY IN HISTORY

Henry David Thoreau dies, "The Grapes of Wrath" wins the Pulitzer, and more.

Russell McLendon

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Photo (wildfire in a Russian wheat field in 2010): ZUMA Press

Photo (two Arctic harbor seals): Alaska Department of [skipwords]Fish[/skipwords] and Game

Photo (Louisiana estuary): National Oceanic and Atmospheric Administration

Photo (space shuttle launching): NASA

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