MIT researchers are advising the government to use natural gas as a low-carbon bridge to a cleaner energy society, but they warn renewables must be developed lest gas become a bridge to nowhere. "The scenario goes like this, according to MIT: Nuclear power, renewable energy and carbon capture and sequestration are relatively expensive next to gas. Conventional coal is no longer a major source of power generation in the United States. 'Natural gas is the substantial winner in the electric sector: The substitution effect, mainly gas generation for coal generation, outweighs the demand reduction effect,'" writes Scientific American.