A coalition of environmental advocates has filed three initiative petitions for the 2020 ballot, saying they plan to take a carbon cap directly to voters after the Oregon Legislature failed to pass one this year.

The first potential ballot measure would require the state to reduce greenhouse gas emissions to 50 percent below 1990 levels by 2035 and to 100 percent "carbon free" by 2050.

The second would require all electricity to be free of carbon emissions by 2045. (More than 48 percent of Oregon's electricity comes from coal and other fossil fuels now, the advocates say.) The third initiative petition is a variation on the electricity proposal.

The initiative petitions come after Oregon's Republican senators fled the state this spring to block the quorum necessary for a vote on House Bill 2020, a carbon cap. They were wooed back to town with a pledge from Senate Democrats not to vote on the bill, because Democrats in the more conservative legislative chamber said they didn't have enough votes, even with a quorum.

Democratic leadership in Salem has said it will try again to pass a version of HB 2020 in the short session of the Legislature next year, though it's not clear exactly how they'll keep the Republicans in the state for the required quorum.

The initiative petitions provide some leverage for doing so—Republicans will have to choose between compromise in the Legislature or an expensive fight at the ballot—though environmental advocates say they have not abandoned their effort to get legislative action.

"One way or another we're going to listen to Oregonians and act on climate in 2020," says Renew Oregon spokesman Brad Reed. "We hope the legislature will do that. If the legislature walks away without significant and bold climate action, we are prepared to go forward."

Opponents of HB 2020 say that legislation continues to be unpopular with voters.

"If Renew Oregon believes that cap-and-trade is the best approach to reducing carbon emissions, why didn't they file it as an initiative alongside these ballot measures?" asks Oregon Manufacturers and Commerce spokesman Preston Mann. "It's because they know the public does not support a program that would hammer Oregonians with significant cost increases in the name of a policy that offers imperceptible benefits. This new group of initiatives is clearly meant to try and exert influence over the legislative process by essentially saying 'pass cap and trade, or else."