Oil prices finally take a tumble on weakening demand; scientists propose ways to geoengineer a cooler climate; and clever new ways to keep cattle from burping methane. It’s the midweek edition of The Daily Five.

Oil prices drop back below $130 in London and New York: High gasoline prices seem to be doing what no amount of lecturing or common sense could accomplish — lower demand for oil. Despite a brief spike on reports of escalating violence against Nigerian petroleum facilities, the price of crude finally turned downward Tuesday, closing below $130 a barrel in American and European markets. That could bring some short-term relief to drivers, who have been staggered by record gasoline prices since January. The price for a gallon of gas is hovering near $4 in the United States, though prices traditionally decline following the Memorial day holiday. (Telegraph.co.uk)

Geoengineering Could Slow Down Global Water Cycle: From our Rife With Danger Department this morning: scientists speculate artificially reducing the sunlight which reaches Earth’s surface could slow climate change. A study just published by the Lawrence Livermore National Laboratory suggests tactics such as spreading sunlight-blocking aerosols in the upper atmosphere or even orbital sun shades could keep temperatures in check and favorably manipulate rainfall patterns. Of course, climate modeling is still a somewhat conjectural science — and the term “unintended consequences” isn’t something you’d want to hear on whatever passes for the evening news in 2050 or so. (Science Daily)

Honda Leasing First Ever Consumer Fuel Cell Car : It appears Honda is still on track to become the first major automaker to bring a real fuel cell car to market. That’s if you don’t mind leasing, and live in one of three California test markets. Honda says they expect to offer its attractive FCX Clarity coupe in July. The car’s range will be quite acceptable: 270 miles on an average fill. The big caveat, of course, is that there’s very little hydrogen infrastructure beyond the city limits of Torrance, Irvine, and Santa Monica. The Clarity rollout will give Honda the chance to see how their new vehicles really stand up to real-world driving. (EcoGeek)

Green Highways:Environmentally Friendly Asphalts Target of New Research Program: Asphalt is so common in modern society that we hardly give it any thought. But the scale on which asphalt is utilized makes it a prime target for energy saving. Scientists hope to improve methods for laying asphalt without the usual prractice of heating it to nearly 300 degrees. A South African method may point the way, grinding asphalt into powder and keeping it suspended in a soapy solution until ready for use. (Newswise)

Extra Cheese, Hold the Methane: Scientists in Australia and New Zealand are hoping to slow the cattle industry’s environmental impact. It’s well-known that cattle produce a dramatic amount of methane — a potent greenhouse gas thought to be worse than carbon dioxide. Researchers hope that low-enzyme, genetically modified grasses might do the trick. There’s a catch: commercially raised cattle are mostly fed corn and soybeans, not grass. And there’s still the issue of the deforestation and watershed damage caused by large-scale cattle production. (WorldChanging)