FOOD FOR THOUGHT: Wal-Mart hasn't stopped thinking globally, but the world's largest retailer is launching a plan to start acting much more locally, potentially transforming the way food is grown and moved around the planet. Unveiled Thursday, the new plan sets distinct food-sourcing goals for each country where Wal-Mart operates, all designed to boost the amount of locally grown food sold in its stores by 2015. The goals depend largely on how ingrained its current practices are in each country — in the U.S., for example, it plans to double its sales of local produce to 9 percent of purchases (it defines "local" as food grown and sold in the same state), while its smaller presence in Canada lets it set a more ambitious goal of 30 percent. The company has also pledged to sell $1 billion of food from small and medium farms (defined as those with fewer than 50 acres) in emerging markets like China and India, as well as to invest $1 billion in improving its supply chain for perishable food. It's all part of a broader overhaul the company began five years ago, hoping to clean up its eco-unfriendly image by switching to renewable energy, eliminating waste, selling more sustainable products and working with many of the same environmental groups that were once its biggest critics. That has led Wal-Mart to a variety of changes recently — such as rolling out hybrid semi-trucks, selling smaller detergent packages and recycling plastic bottles into dog beds — but none matches the scope of this most recent announcement. Wal-Mart is the world's No. 1 grocer, and that means it wields enormous influence in determining how entire markets operate, points out Michelle Harvey of the Environmental Defense Fund, one of the advocacy groups that advised Wal-Mart on its new plan. "This is where Wal-Mart's scale enables them to do what other retailers aren't large enough to do," Harvey tells the [skipwords]Washington[/skipwords] Post. "They really can change a market." (Sources: New York Times, Washington Post)

COLORS OF THE WIND: Insects are attracted to certain colors of paint on wind turbines, a new study has found, suggesting an unexpected explanation for why turbine blades occasionally kill birds and bats. Wind turbines are often painted white or gray to keep them from being visually obtrusive, but that apparently makes them stand out even more to certain migrating insects, which swarm to the light-colored turbines and subsequently bring bug-eating birds and bats along for the ride, the researchers report. "We found it extremely interesting that the common turbine paint colors were so attractive to insects," says Chloe Long of the U.K.'s Loughborough University. "No other study has looked in detail at what specific insect species might be attracted to turbine installations or why." The researchers tested a range of turbine colors and found that white and gray trailed only yellow as the leading bug baiters, attracting small and large flies, greenflies, moths, butterflies, thrips, beetles and crane flies — many of which in turn attract bats and birds that are sometimes killed by turbines' spinning blades. Purple was the least attractive paint color, but the researchers stop short of calling for an emergency purpling of the planet's wind farms. "If the solution were as simple as painting turbine structures in a different color this could provide a cost-effective mitigation strategy," Long says, adding that other factors such as heat given off by turbines may also attract insects and their predators. Some 20 to 40 bats are killed annually by a single turbine on some wind farms, although death rates of one to three bats are more common. (Source: BBC News)

LOVE DOESN'T HURT: Intense feelings of love can provide surprisingly powerful pain relief, on par with narcotic painkillers and illegal drugs like cocaine, according to a new study published in the journal PLoS One. "When people are in this passionate, all-consuming phase of love, there are significant alterations in their mood that are impacting their experience of pain," says Stanford University professor and lead author Sean Mackey. "We're beginning to tease apart some of these reward systems in the brain and how they influence pain. These are very deep, old systems in our brain that involve dopamine — a primary neurotransmitter that influences mood, reward and motivation." That doesn't necessarily mean patients with chronic pain should replace Tylenol with a tryst, though; the researchers are more interested in finding new brain pathways for pain relief, which could then be recreated with a drug or therapy. "It turns out that the areas of the brain activated by intense love are the same areas that drugs use to reduce pain," says Arthur Aron, another of the study's authors. "When thinking about your beloved, there is intense activation in the reward area of the brain — the same area that lights up when you take cocaine, the same area that lights up when you win a lot of money." The researchers induced pain in test subjects using a thermal stimulator placed on their hands, and then showed them photos of their romantic partners as well as an equally attractive acquaintance. The photo of a subject's partner was much more effective at alleviating pain, working at least as well as the already-proven technique of distraction, although using a different brain pathway. This could lead to more effective methods of pain relief, the researchers say, without as many side effects as existing drugs. "This tells us that you don't have to just rely on drugs for pain relief," Aron says. "People are feeling intense rewards without the side effects of drugs." (Source: Stanford University)

CLIMATE COMPREHENSION: Nearly two-thirds of Americans acknowledge that global warming is happening, but many don't understand quite how or why, according to a new national survey conducted by Yale University. The "Americans' Knowledge of Climate Change" report found that 63 percent of respondents agree the planet is rapidly growing warmer, although only 57 percent know what the greenhouse effect is, just 45 percent understand that carbon dioxide traps heat from escaping into space, and about 50 percent accept that global warming is caused primarily by human activities. There is also widespread confusion about what does cause global warming, with large majorities of respondents incorrectly answering that the ozone-layer hole and aerosol spray cans are responsible. And a whopping three-quarters are unaware of related environmental problems such as ocean acidification or coral bleaching (pictured). But most Americans at least know they don't know everything about climate change — only one in 10 say they're "very well-informed" about the process, and 75 percent say they'd like to know more about it. The same percentage says schools should teach children more about climate change, and 68 percent say they'd support a national educational program to that effect. "This study demonstrates that Americans need to learn more about the causes, impacts and potential solutions to global warming," says study director Anthony Leiserowitz. "But it also shows that Americans want to learn more about climate change in order to make up their minds and take action." (Sources: Science Centric, Yale University)

Russell McLendon

Want to receive the day's eco-news in your inbox? Click here to sign up for the Daily Briefing newsletter.

Photo (Walmart employee stocking shelves): Chris Hondros/Getty Images

Photo (spinning wind turbine): Kim Steele/Getty Images

Photo (OxyContin painkiller tablets): Toby Talbot/AP
Photo (bleached coral): National Institute of Standards and Technology

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.