WASHINGTON — At a time when the country is already deeply fractured along partisan lines, individual states are starting to pursue vastly different policies on climate change with the potential to cement an economic and social divide for years to come.

A growing number of blue states are adopting sweeping new climate laws — such as New York's bill, passed this week, to zero out net greenhouse gas emissions by 2050 — that aim to reorient their entire economies around clean energy, transforming the way people get their electricity, heat their homes and commute to work.

But these laws are passing almost exclusively in states controlled by Democrats, while Republican-led states have largely resisted enacting aggressive new climate policies in recent years. At the same time, the Trump administration is rolling back federal climate regulations, which means many red states now face even less pressure to shift away from coal power or gas-guzzling vehicles.

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"What we're seeing is a tale of two climate nations," said Barry Rabe, a professor of public policy at the University of Michigan. "The split has become much more pronounced in recent years."

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Over the past year, Democratic majorities in California, Colorado, Maine, Nevada, New Mexico, New York and Washington have all passed bills aimed at getting 100 percent of their state's electricity from carbon-free sources like wind, solar or nuclear power by midcentury, while enacting a raft of measures to install more electric-vehicle charging stations and ratchet up efficiency codes for buildings. In all, these states plan to invest billions of dollars to shift away from fossil fuels, the major driver of global warming.