The Trump administration’s deepest impact on domestic climate policy might have little to do with its efforts to dismantle the Clean Power Plan or its decision on the Paris accord.

Instead, the coming battle over the future of the Energy Department could prove far more significant for the United States’ long-term efforts to cut greenhouse gas emissions.

Among energy experts, there is broad agreement that the world still needs major technological advances to halt global warming, like better batteries to integrate larger shares of solar and wind power into the grid, or carbon capture to curb pollution from cement plants.

Historically, the Energy Department has nurtured these kinds of innovations, conducting basic research in its network of 17 national laboratories and aiding private firms struggling to bring risky technologies to market. But those efforts would be drastically scaled back under President Trump’s fiscal 2018 budget proposal, released on Tuesday, which proposes to cut the agency’s energy programs by $3.1 billion, or 18 percent below last year’s levels.