Brown rice. White rice. Sushi. Rice pudding. Rice in all its wonderful forms is the main food source of over three billion people, which makes this statistic all the more ominous: Right now, droughts and floods threaten over 25% of Earth’s rice harvests. But that doesn’t faze one group of scientists who have discovered that rice evolved to to resist floods also resist droughts.
The gene Sub1A, which is found in a few strains of rice, is responsible for this dual flood-drought protection. The researchers who discovered it in 1996 feared that a gene that protects a plant against flooding might make it especially sensitive to drought. So UC–Riverside researcher Julia Bailey-Serres and her colleagues were all the more surprised that the Sub1A gene actually makes rice better at coping with water shortage. This welcome trait became apparent after the water-starved plants grew fresh shoots after the researchers subjected the plants to a mock drought in the lab.
So how does a single gene work against both floods and droughts? The gene triggers a stressed plant to go dormant (whether that stress is an overabundance or lack of water) until the environment recovers from that stress. This may seem like an ability of limited use out in the world, but it’s actually important for some plants. After water levels go down at the end of a flood, a rice plant that had grown accustomed to soaking in water becomes dehydrated, as if it were suffering through a drought. As strange as it sounds, drought is a natural process in the flooding cycle, and it’s this fact that tricks the Sub1A gene into allowing rice plants to become dormant during both floods and droughts, conserving energy for up to two weeks, before reawakening after the waters recede or rain finally returns.
This gene for flood tolerance only naturally occurs in certain low-yielding rices in India and Sri Lanka, but scientists have already genetically engineered some high-yielding rice to exhibit this trait—which means that some farmers have also unknowingly been protecting their crops from droughts as well.
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Image: flickr / matsuyuki
“This is probably going to wind up being the first salvo in a pretty significant debate.” That’s what political scientist Cullen Hendrix told New Scientist in November of last year, when a study came out proclaiming the climate change would spur an uptick in civil wars in Africa. He was correct. This week, another study that will be published (in press) in the same journal—Proceedings of the National Academy of Sciences—says there is no proof to back up such a connection.
The argument for a link between global warming and war came from UC-Berkeley economist Marshall Burke, who said that food shortages and drought brought on by climate change could cause 50 percent more armed conflict by 2030 under the scenarios that climate models predict. However, Norwegian political scientist Halvard Buhaug looked at sub-Saharan civil war over the last half century for this week’s study. When he compared the records of military conflict with the records of temperature and rainfall, did not see a correlation between the two.
[Buhaug] found that that there was a strong correlation between civil wars and traditional factors, such as economic disparity, ethnic tensions, and historic political and economic instability. [BBC News]
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It’s a good thing that the early English settlers of America were hardy and stubborn, because they certainly didn’t have good timing. The settlers who established the Jamestown colony in Virginia is 1607 arrived during a historic drought, according to the records kept in tree rings, the worst in the area in 800 years. And now researchers have created an even more detailed picture of the dire climate situation those colonists stumbled into, and they did it with the colonists’ trash.
Oyster shells, to be exact.
The telltale oysters were unearthed from a well that sat within the fort at Jamestown, about 100 yards from the [James] river. Among other material dumped into the well, the shells came from three distinct layers up to 3.5 meters deep. The well’s water level originally sat deeper, at a depth of about 4 meters, so Spero and his colleagues suggest that the settlers abandoned the well — which either ran dry during the drought or was infiltrated by salty groundwater — and converted it into a trash pit [Science News].
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For years, farmers in Kenya’s arid north have suffered huge losses when droughts wiped out their cattle herds. Now, they have a means to protect their sole source of livelihood when rains fail and grasslands disappear. A new insurance scheme hopes to safeguard cattle-rearers in northern Kenya’s drought-prone Marsabit district by using satellite imagery to track changing landscapes and the subsequent loss of cattle.
The program, launched by the International Livestock Research Institute, is being billed as the world’s first insurance program to track changing pastoral grounds. When the satellite photos reveal that a verdant green landscape has changed to a dry brown, the insurance kicks in and farmers can collect their payments. The program will make things easier for insurance companies–for whom estimating losses in the past has been all but impossible. Partly because it has simply been too expensive for insurers to go and count the number of dead animals which might be spread over a vast rural area [BBC]. The scheme’s launch comes at a time when the Marsabit region has suffered 28 droughts in the last 100 years and four in the past decade alone [Kenya Broadcasting Corporation].
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The region today known as Iraq was once known as Mesopotamia, which means “Land Between the Rivers,” and since that ancient time the land between the Euphrates and Tigris rivers has been renowned for its fecund soil and thriving farms. But now the Mesopotamian cradle of civilisation seems to be returning to desert [New Scientist].
Decades of war and mismanagement, compounded by two years of drought, are wreaking havoc on Iraq’s ecosystem, drying up riverbeds and marshes, turning arable land into desert, killing trees and plants, and generally transforming what was once the region’s most fertile area into a wasteland…. “We’re talking about something that’s making the breadbasket of Iraq look like the Dust Bowl of Oklahoma in the early part of the 20th century” [Los Angeles Times], said Adam L. Silverman, a social scientist with the U.S. military.
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Fierce dust storms this spring have stained Colorado’s snow-covered peaks with brown, red, and pink dust, and state officials point out that this isn’t just a change in scenery. The darker snow is absorbing more radiation from the sun and is therefore melting faster and sooner than it normally would, which is upsetting the careful water rationing that defines life in the American West. Twelve dust storms barreled into the southern Rockies from the deserts of Arizona, Utah and New Mexico so far this year…. That, coupled with unseasonably warm temperatures, has sped up the runoff here, swelling rivers to near flood stage, threatening to make reservoirs overflow and fueling fears that there will not be enough water left for late-summer crops [Los Angeles Times].
In Colorado, melting snow accounts for about 80 percent of the water that flows through rivers and ends up in the state’s lakes and reservoirs. Colorado water engineer Scott Brinton explains that the early snowmelt could spell disaster for thousands of farmers and ranchers in the region who depend on slowly melting snow to provide water flows over the dry summer months…. “Those people who were relying on the mountain snowpack are going to have difficulty later in the year…. There’s not a whole lot we can do about it,” Brinton said. “We’re telling people, ‘You’ll be getting your water early this year, so use it while it lasts’” [Greenwire]. But scientists note that this may not be just a year of freak storms, it may be a harbinger of things to come.
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West Africa has a history of severe, prolonged “mega-droughts,” according to a new study, and researchers say that another one is inevitable, although they can’t say when it might occur. Says lead researcher Tim Shanahan: “It’s disconcerting – it suggests we’re vulnerable to a longer-lasting drought than we’ve seen in our lifetime…. If the region were to shift into one of these droughts it would be very difficult for people to adapt; and we need to develop an adaptation policy” [BBC News].
The study, which examined sediment samples on a lake bottom to trace the climate history back 3,000 years, reveals that the infamous 1970s drought of the African Sahel region, which lasted several decades and killed more than 100,000 people, was actually a “minor” event…. “What’s disconcerting about this record is that it suggests the most recent drought was relatively minor in the context of the West African drought history” [New Scientist], says Shanahan. The researchers found that decades-long droughts similar to the 1970s event occur every 30 to 60 years, but that even more severe, century-long droughts have reoccurred as well. The most recent mega-drought began in 1400 and lasted until 1750, during which time forests grew up in dry lake beds.
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Researchers have found that droughts kill pine trees faster when temperatures are higher, a piece of information that bodes ill for forests in a warmer world. A new study examined the effect of dry conditions and temperature on the pinion pine, a hardy evergreen that lives in the American Southwest, and found that “together, drought and temperature can kind of provide a double whammy,” said David Breshears, a researcher involved in the experiment [Reno Gazette Journal].
Researchers could isolate the impact of heat due to the unusual environment where the experiment took place. The study was conducted in Biosphere 2, a glass and steel laboratory that includes recreations of the planet’s savannas, deserts, oceans and forests…. Half the pinions studied were kept in normal temperatures, the others in an environment 7 degrees warmer. Some trees in each group were then deprived of water to simulate droughts common in the past [AP]. Trees subjected to higher temperatures died five times faster than the other trees, suggesting that even short droughts could produce widespread tree mortality in a warmer climate [AP]. The study was published in the Proceedings of the National Academy of Sciences.
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In preparation for future oil shale mining projects near the Rocky Mountains, six oil companies have gained rights to billions of gallons of water in the American West, potentially jeopardizing water supplies throughout the region, according to a new report by Western Resource Advocates [pdf], an environmental group. It is still preliminary to speculate on the implications of the findings, but many are concerned that if the companies put their rights to use, water will be shifted away from agriculture and community use.
Using public records, the report examines more than 200 water rights held by six energy companies, including Shell and ExxonMobil, which, it is estimated, are collectively entitled to divert at least 6.5 billion gallons of water from rivers in western Colorado, as well as almost 2 million acre-feet of water from the state’s reservoirs, which is enough to supply the Denver metro area for six years. Shale oil production is a water-intensive process: up to five barrels of water are consumed for every barrel of oil produced. This means that projects producing 1.55 million barrels of oil per day would require 378,000 acre-feet of water each year, compared to the Denver metro area’s consumption, which is less than 300,000 acre feet. Should oil shale production hit full stride in the next 15 to 20 years — something the White House under President George W. Bush tried to accelerate by opening up 2 million acres controlled by the Bureau of Land Management to leasing and approving royalty rates and leasing rules — there will be a major political battle over water rights [Colorado Independent].
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Trees in the old-growth forests of the American West are dying at an accelerating pace, and researchers say that the early impacts of global warming are probably to blame. The bad news was found in California, the Pacific Northwest, and in the interior Western states. Says study coauthor Phillip van Mantgem: “Tree death rates have more than doubled over the last few decades in old-growth forests across the Western United States.” … The researchers found rising death rates across a wide variety of forest types, at different elevations, in trees of all sizes and among major species, including pine, fir and hemlock [Los Angeles Times].
Van Mantgem says that average temperatures in the West have risen by more than 1 degree Fahrenheit in the last few decades. “While this may not sound like much, it has been enough to reduce winter snowpack, cause earlier snowmelt, and lengthen the summer drought” [Reuters], he says. Droughts make trees more stressed and vulnerable to disease, and warmer temperatures have also allowed the spread of pine beetles and other pests that attack trees. And while the death rate of old trees is increasing, the rate of new trees sprouting and surviving has not risen.
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A federal judge declared that California‘s water management system is jeopardizing the existence of the state’s salmon and steelhead, which have to navigate the complicated network on their journeys out to the ocean and back to their riverine spawning grounds. The judge’s ruling established that the canals and pumps that deliver water to 23 million Californians are causing “irreparable harm” to two salmon species, as well as the threatened Central Valley steelhead [AP].
The judge stopped short of ordering immediate remedies like storing more water behind Shasta Dam, which could be released later to help migrating fish. But the judge’s conclusions mean regulators will be forced to impose more protective conditions when they issue a new permit in March, lawyers said. “It’s a clear signal that business as usual in the Delta is not going to be acceptable,” said Kate Poole, a lawyer for the Natural Resources Defense Council [Contra Costa Times].
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An agricultural region that produces over 40 percent of Australia‘s fruit, vegetables, and grain is seriously threatened by the country’s ongoing drought, which has been developing into a crisis over the last decade. Scientists say that the two mighty rivers that irrigate the Murray-Darling Basin (an area the size of France and Germany combined) received the lowest amount of replenishing autumn rain since record-keeping began over a century ago.
Neil Plummer, acting head of the National Climate Centre, described rainfall during the southern hemisphere autumn as “an absolute shocker”, and said: “I’m gasping for good news”. Wendy Craik, chief executive of the Murray-Darling Basin Commission, said the river system’s condition was “critical… tending towards flatlining”. She added: “We have got it on life support” [The Independent].
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It’s official: California is in a state-wide drought, according to Governor Arnold Schwarzenegger. Following the driest spring in 88 years, the state’s reservoirs are low, its farmers are complaining, and its forests are tinder-dry, which may lead to more forest fires like the one that scorched the Santa Cruz mountains two weeks ago.
In giving the current dry spell the official “drought” stamp for the first time since 1991, the governor cleared the way for water transfers to stricken areas and a possible infusion of federal aid to speed water conservation projects. But Schwarzenegger stopped short of declaring a water emergency, which would permit water rationing.
Some researchers have wondered whether the state is already suffering the early effects of global warming, which is predicted to alter California ecosystems by raising temperatures, and thus allowing less snow to build up in the mountains of Northern California.
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