fossil fuels

Louisiana is the latest state to redefine natural gas as green energy, even though it’s a fossil fuel that emits planet-warming greenhouse gases.

The U.S. aims to reduce carbon dioxide emissions by 80 percent by 2050. Wind and solar power can help. But folks doing the math say other pricey, controversial technologies — such as burying carbon gas underground, and expanding nuclear power — are also likely to be part of a low-carbon future.