The Trump administration took aim at two Obama-era environmental policies on Dec. 6 to boost the oil and coal industries, proposing to open up a bird's wildlife habitat to drilling and mining and remove hurdles to new coal-fired power plant construction.

The moves, part of a broader agenda by U.S. President Donald Trump to revive the ailing coal industry and ramp up domestic energy production, come amid increasingly urgent warnings from within his own government about climate change, and as world leaders gather at a United Nations conference to combat planetary warming.

Announced separately by Trump appointees who were both former energy lobbyists, the proposals cheered the coal and oil industries but triggered an uproar from environmental groups who raised the prospect of legal challenges.

"Trump and his deputies are delivering on the wish list of the coal and oil industries, but they are up against the public and market demand for clean energy," said Mary Anne Hitt, senior director of Sierra Club's Beyond Coal campaign.

The U.S. Interior Department proposed easing Obama-era protections for a bird, the greater sage-grouse, to boost oil drilling and mining across Western states, potentially opening up hundreds of thousands of acres of grouse habitat in states like Colorado and Utah to oil and gas leasing.

Announced by Interior Department Deputy Secretary David Bernhardt, a Colorado native and a former energy lobbyist, the proposal would allow for changes to habitat boundary maps of the chicken-sized prairie fowl—considered by conservationists to be a key indicator species for America’s dwindling sagebrush ecosystem.

The Obama administration had launched the plan to protect the sage-grouse in September 2015 as an alternative to listing the ground-dwelling bird under the Endangered Species Act, a move that would potentially have entailed even tougher habitat protections. The oil and mining industries, however, have said the limits to development are overreaching.

Also on Dec. 6, the U.S. Environmental Protection Agency (EPA) proposed rolling back an Obama-era rule requiring new U.S. coal plants to slash carbon emissions, a move that could crack open the door in coming years for new plants fired by the fossil fuel.

Rejecting criticism that the move would potentially increase carbon emissions, acting EPA Administrator Andrew Wheeler, a former coal lobbyist, argued that the move would encourage cleaner coal investments in the U.S., which would then be exported worldwide and help reduce global emissions.

It is unclear if the move will spur any new construction of coal plants in the U.S., however, as many utilities turn to cheaper natural gas and renewables like solar and wind energy. The U.S. government lists only two major coal-fired power plants scheduled to come online over the next five years, with more than 70 scheduled to retire over the same period.

Since taking office in January 2017, Trump has made a habit of rolling back Obama-era environmental and climate protections to maximize production of domestic fossil fuels, including crude oil. U.S. oil production is already the highest in the world, above Saudi Arabia and Russia, after a boom that was triggered more than a decade ago by improved drilling technology.

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Trump's agenda to encourage more fossil fuels use clashes with a congressionally mandated government report that came out last month saying climate change is driven mainly by human activity and will cost the U.S. economy hundreds of billions of dollars by the end of the century.

The White House has discounted the report, saying it fails to account for potential advances in technology that could make burning fossil fuels cleaner in the future.