For more than a decade, Congressional Democrats and a growing share of their political base have chased a dream: legislation to combat climate change, large enough to transform our society into one equipped to avert the worst catastrophes of a rapidly warming planet.

On Wednesday the dream made a giant leap toward reality.

In a stunning reversal from when he appeared to kill a climate deal just two weeks ago, U.S. Sen. Joe Manchin, a conservative West Virginia Democrat, announced support for the Inflation Reduction Act of 2022, a bill that would invest about $370 billion into a range of policies aimed at reducing U.S. greenhouse gas emissions. That would make it the most substantial effort by the federal government to tackle climate change in history.

A vote on the bill could come within a week, though supporters are bracing for any last-minute hurdles.

Early reaction suggests the bill could transform the American energy and transportation sectors. Tens of billions of dollars will go toward supporting renewable energy development, lowering the costs of electric vehicles, building out public charging stations, weatherizing homes, plugging leaks of greenhouse gases from pipelines and wells, lowering emissions from the agricultural sector, and supporting communities located near polluting industries.