An outline of the soon-to-be-unveiled “Green New Deal” says the proposal set a goal of achieving net-zero emissions — rather zero emissions — in the U.S. because it is not possible to eliminate “farting cows” and airplanes” within the next decade.

A handful of progressive Democrats, including Rep. Alexandria Ocasio-Cortez (D-NY), are calling for a Green New Deal intended to transform the U.S. economy to combat global warming and “systemic injustices.” The 29-year-old congresswoman and Sen. Ed Markey (D-MA) are teaming up on the plan and are scheduled to discuss it at a press conference Thursday.

The outline’s FAQ section addresses why the proposal seeks to shift from “100% clean and renewable” instead of strictly using energy which is “100% renewable.”

The answer reads:

“We set a goal to get to net-zero, rather than zero emissions, in 10 years because we aren’t sure that we’ll be able to fully get rid of farting cows and airplanes that fast, but we think we can ramp up renewable manufacturing and power production, retrofit every building in America, build the smart grid, overhaul transportation and agriculture, plant lots of trees and restore our ecosystem to get to net-zero.”

A joint resolution expected to be introduced Thursday sets a goal to meet all power demand in the U.S. through zero-emission energy sources by 2030. Use of wind and solar power would be dramatically increased under the plan.

The Democrats are likely to meet resistance to their proposal in Congress, especially in the Republican-controlled Senate.

The announcement of the Green New Deal came as Pelosi tapped eight Democrats to serve on a special committee to address climate change. Ocasio-Cortez was not among those selected for the panel, which is chaired by Rep. Kathy Castor (D-FL).

The freshman lawmaker has yet to comment on the snub.

Pelosi said in a statement that the climate committee will “spearhead Democrats’ work to develop innovative, effective solutions to prevent and reverse the climate crisis.” She made no mention of the Green New Deal.

The resolution being introduced Thursday marks the first time Ocasio-Cortez and other lawmakers have attached legislative language to the Green New Deal, a concept that until now has been largely undefined other than as a call for urgent action to head off catastrophic climate change and create jobs.

The Associated Press contributed to this report.