With U.S. carmakers facing tough times, questions over whether Chevy’s Volt electric car will make it to market; buried forests to combat climate change; and cutting urban srawl could have a big green payoff. It’s the midweek edition of The Daily Five.

Could Recession Crash the Volt?: Rising gasoline prices and tight credit are putting the squeeze on American automakers, including mighty General Motors. After all the progress made toward the launch of the Chevy Volt, will GM remain in a position to complete its costly development? The company is sitting on $24 billion in cash reserves, but sluggish sales cost GM over $3 billion in the last quarter alone. The Volt is expected to come to market sometime in the next two years. (GM-Volt)

Put The Trees In The Ground: A Fix For The Global Carbon Dioxide Problem?: Save the trees — for deep burial. Researchers at Germany’s University of Greifswald are proposing a novel trap to draw carbon dioxide out of the environment: massive temporary forests. Trees are natural carbon sinks, but their stored carbon is released as their wood burns or decays. Not if you bury them. The Greifswald plan suggests entombing “carbon forests” at peak maturity, effectively removing their contained CO2 from the biosphere. (Science Daily)

Sweet sorghum promoted as “smart” biofuel: The race is on to find replacements for food-based biofuel stock. The use of corn and sugar has helped spike world food costs. Now scientists are taking a good look at hardy sweet sorghum, which can grow under difficult conditions while providing four times the energy yield of corn-based ethanol. Best of all, sorghum can be harvested for biofuel without sacrificing the food grains which grow at the top of its stalk. (Reuters)

Nissan to Introduce Electric Vehicle in US and Japan in 2010; New Business Plan Focuses on Zero-Emission Vehicle Leadership: Nissan is getting into electric cars in a big way, promising to debut a plug-in no later than 2010. Green Car Congress reports Nissan sees value in establishing leadership as a zero emissions car company. Nissan’s plans are incorporated in a company roadmap known at Nissan GT 2012. The G and T stand for Growth and Trust.

Combating Climate Change by Tackling Sprawl: Jetson Green contributor Jeff Stephens points out that one of our biggest tools to reduce long-term greenhouse gas emission levels is stomping out urban sprawl. A study published by the Urban Land Institute calculates that a full 30 percent of U.S. carbon dioxide emission are caused by transportation. The solution: hhifting about 60 percent of new urban growth to compact, mixed-use communities with walkable, bike-able neighborhoods. (Jetson Green)