GETTING OFF TRACK? Just as Americans are finally getting on board for a railroad renaissance in the name of cutting CO2, new research questions whether trains are really the green god-sends we think they are. Published today in the journal Environmental Research Letters, the study looks at the "full life-cycle" emissions produced by 11 different modes of transportation in the United States, and finds that — under certain conditions — trains and buses may be no eco-friendlier than planes. Previous studies focused on the direct "tailpipe" emissions generated by cars, trains, buses and planes, but the new study also factors in emissions from building and maintaining the vehicles and their infrastructure. This more than doubles the carbon footprint of train travel, especially in places like Massachusetts, where 82 percent of the electricity that powers Boston's trains is generated from coal. Compared with trains and other mass transit, airplanes have relatively little infrastructure, so their life-cycle emissions are only 10 to 20 percent higher than their tailpipe emissions. Not surprisingly, empty trains and buses have much higher carbon footprints than ones full of people who would otherwise be driving cars. (Sources: Environmental Research LettersScientific American, New Scientist, Agence France-Presse

HOT VS. COLD: As federal stimulus money begins to flow throughout the country, air conditioners are kicking on across the Deep South. Many homes leak this A/C pointlessly into the outdoors, and President Obama's plan to weatherize 1 million homes will nearly double federal efforts to keep hot states cool more efficiently. Weatherization in the past has mainly focused on keeping cold states warm, since the United States spends twice as much on home heating as it does on home cooling, and because heating uses more energy and thus produces more greenhouse gases. The NY Times examines whether it's wise to weatherize so many homes in Florida, even though the plan still dedicates most of its efficiency efforts in cold climes like Minnesota and the Dakotas. (Source: New York Times)

A GOREY BATTLE: Much like God, the Shadow or swine flu, Al Gore is "simultaneously everywhere and nowhere," ABC News reports today. The Nobel-winning ex-VP has held on to a lot of political power for someone who hasn't held elected office in nearly a decade, and he's now flexing that muscle to help push the House cap-and-trade bill closer to reality. He's been advising Obama on climate and environmental matters since Bush was still in power, and lately he's been milking his thick D.C. Rolodex to lubricate the climate bill's tortuous travels through Congress. Still, the Houston Chronicle reports, there are plenty of hurdles along the way, namely competing lawmakers with varying regional agendas, and Reuters points out how daunting a task it is for the Obama administration to overhaul both U.S. energy and health care policy in its first year. (Sources: ABC News, Houston Chronicle, Reuters)

BANKING ON IT: Iran says it just wants to enrich uranium for civilian nuclear power generation — a way to secure its energy independence — and not for nuclear weapons. The United States and other Western nations have long been skeptical of this claim, and now President Obama is calling Iran's bluff, proposing an international uranium bank that would let any nation withdraw fuel for nuclear energy, but would limit their ability to make bombs. Not only would this free up the peaceful power source for more countries, but it would also hinder their ability to use power plants as cover for making nuclear weapons. (Source: Boston Globe)

WINDS OF CHANGE: A small Louisiana enclave with only about 500 homes may become the state's first town to build a wind turbine, the Baton Rouge Advocate reports. Settled in 1720, Washington, La., is the third-oldest settlement in Louisiana, known more for its historic architecture and antiques than for leading the state into new technological frontiers. But Mayor Joseph Pitre hopes to take Washington off the power grid completely, generating all of the town's electricity from the turbine and a methane plant that burns gas from a nearby landfill. "If it works, I see the real estate values going up," Pitre tells the Advocate. "I see people being grateful they live in Washington. I see other people being envious that they don’t live in Washington." (Source: Baton Rouge Advocate)

THERE WILL BE FLOOD: When the Red River began flooding this spring, North Dakota residents sprang into action as they had many times before, throwing sandbags into the face of impending disaster. The humans mostly won the battle, even resorting to dynamite in some places to loosen melting ice as the river's bank swelled to record levels. But the war may just be getting started — flooding in the Upper Midwest is likely to keep getting worse as climate change drives up temperatures and increases precipitation in the region, the Grand Forks Herald reports today. "Certainly, there's a trend toward these heavier rainfall events and heavier rainfall seasons," one climate scientist tells the paper. "That obviously increases the risk of flooding." The number of days with more than 4 inches of precipitation has increased by 50 percent in the past century, and the topography of the Red River Valley is already primed for flooding. (Source: Grand Forks Herald)

FUNNEL VISION: Exuberant storm chasers Reed Timmer and Joel Taylor are all over YouTube, screaming and cheering as they tail tornado after tornado across the Great Plains and Midwest. In this video from Friday, the gang takes its antics to a new level in Goshen, Wyo., driving in front of an oncoming twister and letting it hit their car so they can take measurements — and film it through a "roof bubble cam." Their equipment recorded 155 mph winds as the tornado passed overhead. For more funnel-cloud footage, check out MNN's top 10 tornado videos. (Source: via Digg

— Russell McLendon

(Photo: ZUMA Press)