The states most active on climate change announced plans to cut short-lived planet-warming pollutants like methane and black carbon, and expand clean-energy financing.

The 16-state U.S. Climate Alliance’s unveiling of the initiatives June 1 coincided with the one-year anniversary of President Donald Trump’s decision to pull the U.S. out of the Paris Agreement.

The steps were intended to show that action would continue to build at the state level even as the Trump administration moves toward a formal withdrawal from the international climate agreement in 2020.

Part of the Climate Alliance’s plan is to cut hydrofluorocarbons (HFCs), black carbon,...