SALEM — Lawmakers revealed changes Wednesday to the plan to cut back on the state’s greenhouse gas emissions that would ease the impact on rural Oregon.

The revisions, which contain elements proposed by Timber Unity, are part of the continuing effort by Democratic sponsors to drive a policy that has greater statewide acceptance.

The proposed revisions to Senate Bill 1530 incorporate requests from Republicans and Timber Unity, a grassroots organization that has been agitating against a cap-and-trade system. Republicans in the Senate fled the state over last year’s version of the bill.

The bill was slated for a work session in the Senate Committee on Environment and Natural Resources Thursday.

The cap-and-trade program would set a limit on statewide carbon emissions and aims to reduce emissions over time.

Limits on emissions would apply to certain industries and major fuel importers. The policy would carve up the emissions limit into allowances that emitters can buy and sell on a market. The idea is that as emissions targets get lower, fewer allowances would be available, and industry would improve pollution controls.

Opponents have criticized the plan for its potential impact on consumers and small businesses, particularly through higher fuel costs.

The amendments could change how fuel would be regulated under the program. It would delay the impact on Curry and Coos counties, as well as the Bend and Klamath Falls metro areas until 2028, six years later than for the Portland area.

And rather than 20 counties triggering a statewide adoption of limits on fuel importers, the amendment sets the trigger at 23 counties.

And under the amendment, a greater share of the revenue from transportation — 90% — would go to counties or metro areas that engaged in the program to use on emissions reduction and climate adaptation projects. The rest would go to the state Transportation Department for projects around the state.

The amendments would incorporate policy ideas from Sen. Alan Olsen, R-Canby, and Sen. Lynn Findley, R-Vale, who sit on the Senate Committee on Environment and Natural Resources.

Olsen’s idea would make it easier for state agencies receiving money raised by the program to buy electric vehicles, and Findley’s would streamline a state energy efficiency audit process for manufacturers that use a lot of energy but who face competition from areas that aren’t subject to emissions limits.

The amendment also includes policy ideas borrowed from Timber Unity. For example, it would direct the state’s parks department to conduct an annual tree planting day for local governments to sponsor planting trees in public spaces, and it would direct the state’s main operations agency to study ways to account for the greenhouse gas emissions associated with transporting goods and services that state government buys.

The amendment aims to narrow the information about the program that is exempt from public disclosure just to “trade secrets,” which is already defined in the state public records law.