Since taking office, President Donald Trump has initiated a number of rollbacks against Obama-era climate policies, including pulling out of the Paris climate agreement.

But states are standing up against him: 24 states and Puerto Rico have joined the US Climate Alliance, a bipartisan coalition of governors who vow to stick to the original carbon emission reduction goals set by the Paris agreement.

Each state has committed to policies that aim to reduce greenhouse gas emissions by around 27% below 2005 levels by 2025.

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Since taking office, President Donald Trump has significantly weakened federal policy by pulling out of the Paris climate agreement, working to repeal nearly 100 environmental protection laws, and continuously advocating for the use of coal.

But states are fighting back.

Since 2017, nearly half of state governors and Puerto Rico have signed legislation that will uphold Paris agreement emission reductions.

But it's not clear if it's enough. According to 2016 data, these 25 members account for only about 42% of US carbon emissions.

Leah Stokes, an assistant professor of political science at the University of California, said that while state efforts are making an impact, action at the federal level will be required if we want to cut carbon emissions in half and avoid catastrophic warming in the next decade.

"I think it's kind of a race with the clock at this point in time," she told Insider. "We know we have to cut our emissions in half by 2030 ... to do that we need to make a lot of progress to clean up our electricity systems."

But that's not to undermine the progress of local governments, Stokes explained. The American public is mobilizing and climate change policy has gained more traction in the 2020 presidential race.

Here's a breakdown of states involved in the US Climate Alliance, and some of the ways they've vowed to combat climate change.