Want climate news in your inbox? Sign up here for Climate Fwd:, our email newsletter.

WASHINGTON — The Environmental Protection Agency plans to change the way it calculates the health risks of air pollution, a shift that would make it easier to roll back a key climate change rule because it would result in far fewer predicted deaths from pollution, according to five people with knowledge of the agency’s plans.

The E.P.A. had originally forecast that eliminating the Obama-era rule, the Clean Power Plan, and replacing it with a new measure would have resulted in an additional 1,400 premature deaths per year. The new analytical model would significantly reduce that number and would most likely be used by the Trump administration to defend further rollbacks of air pollution rules if it is formally adopted.

The proposed shift is the latest example of the Trump administration downgrading the estimates of environmental harm from pollution in regulations. In this case, the proposed methodology would assume there is little or no health benefit to making the air any cleaner than what the law requires. Many experts said that approach was not scientifically sound and that, in the real world, there are no safe levels of the fine particulate pollution associated with the burning of fossil fuels.

Fine particulate matter — the tiny, deadly particles that can penetrate deep into the lungs and enter the bloodstream — is linked to heart attacks, strokes and respiratory disease.