Wendy Koch, USA TODAY12:52 a.m. EDT June 3, 2014

Taking a historic step to fight climate change, the Obama administration proposed a plan Monday that aims to slash carbon dioxide emissions from existing power plants 30% by 2030 and could accelerate the nation’s shift away from coal.

The Environmental Protection Agency plan, which is President Obama’s largest climate effort so far, could help the United States prod other countries like China to pledge similar emissions cuts as part of a new international treaty that’s slate for negotiation next year in Paris.

The controversial 645-page plan, expected to trigger legal challenges, sets different reduction targets for each state and gives them flexibility in how to achieve them. Yet it aims for a 30% national reduction of heat-trapping CO² emissions, from 2005 levels, by 2030 — an amount that the EPA says is equal to annual emissions from powering more than half of U.S. homes.

“This is not just about disappearing polar bears or melting ice caps,” said EPA Administrator Gina McCarthy. “This is about protecting our health and our homes. This is about protecting local economies and jobs.” McCarthy said the proposal will spur innovation and create jobs.

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