The Obama administration is issuing new rules intended to improve fuel efficiency for medium- and heavy-duty trucks, to cut pollution blamed for global warming.

The proposed standards are expected to lower carbon dioxide emissions by about 1 billion metric tons, cut fuel costs by about $170 billion and reduce oil consumption by up to 1.8 billion barrels over the lifetime of vehicles sold under the rule.

The long-expected rules were announced Friday, a day after Pope Francis issued a teaching document calling for the world to take action to slow climate change.

Transportation Secretary Anthony Foxx said the new rules would help the environment and the economy, as trucks use less fuel and shipping costs go down. He called the rules "good news all around."

The Associated Press