Keeping 6 billion people fed boosts global warming more than all the world's cars, trucks, trains, ships, and planes put together. Agriculture accounts for almost 14 percent of greenhouse gas emissions worldwide, according to the latest report from the Intergovernmental Panel on Climate Change. One response is to eat fewer of the two- and four-legged greenhouse gas factories known as animals. Before you send back that T-bone, though, call in the bioengineers.
 

A San Diego start-up says it is using algae to make oil that can be refined into gasoline and other fuels that are both renewable and carbon-neutral, and it plans to produce 10,000 barrels a day within five years.
 
That's a fraction of the 20 million or so barrels of petroleum the United States consumes each day, but Sapphire Energy says "green crude" production could ramp up to a level sufficient to ease our dependence on foreign oil, if not end it altogether.
 

The world's first home ethanol system, which allows consumers to create their own ethanol and pump it directly into their cars, was unveiled today by the E-Fuel Corporation (www.efuel100.com). The revolutionary EFuel100 MicroFueler(TM) is the first product that allows anyone to reduce their dependency on oil, greatly diminish their carbon footprint and produce fuel for under $1.00 per gallon.