Here are the top environmental stories folks are Digging today:

National Geographic: "Methane Bubbling Up From Undersea Permafrost?"

— Ancient methane that's been trapped beneath a "lid" of ocean-floor permafrost is now bubbling to the surface, and Russian scientists say global warming may be the culprit.

• Red, Green and Blue: "New York City To Get LED Street Lighting"

— The Big Apple's Office for Visual Interaction is testing light-emitting diodes that could one day replace all 300,000 of the city's street lamps.

The Christian Science Monitor: "Greens mixed on Obama’s Interior, Agriculture picks "

The CS Monitor highlights environmentalists' varying reactions to Ken Salazar and Tom Vilsack, who are generally embraced but have some unchecked baggage.

• Inventing Green: "250,000 Tiny Greenhouses, Each Containing One Head of Lettuce"

— Inventing Green's Alexis Madrigal examines Britain's WWI-era practice of cultivating lettuce under individual bell-shaped glass "jars."

• UPI: "Amino acid good for sex, helps trees too"

— Arginine, which improves sperm production and genital blood circulation in human males, apparently also helps trees grow stronger root systems and draw nitrogen more efficiently.

Russell McLendon