By Reynard Loki

If the world's governments don't prevent the planet's surface temperature from increasing more than 2 C, then life on Earth will become a difficult proposition for many humans, animals and plants. Glaciers will melt, sea levels will rise, crops will fail, water availability will decrease and diseases will proliferate. Some areas will experience more wildfires and extreme heat; in others, more hurricanes and extreme storms. Coastal cities and possibly entire nations will be swallowed by the sea. There will be widespread social and economic instability, leading to regional conflicts.

Considering that the U.S. is the world's second biggest emitter behind China, accounting for 16 percent of cumulative global greenhouse gas emissions, the climate decisions President Donald Trump and the Republican-controlled Congress make will be critical for future generations. But he has shown no sign that he's remotely interested in tackling what climate scientist James Hansen calls "humanity's greatest challenge."

Contrary to the view of the international scientific community, Trump has called climate change a "con job" and a "myth." In 2012 he tweeted that "the concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive." He cited cold winter weather as evidence that global warming isn't real, tweeting during a 2014 winter blizzard, "The entire country is freezing—we desperately need a heavy dose of global warming and fast! Ice caps size reaches all time high."

So, what could America's newly elected climate-denier-in-chief do to undermine action on the climate threat? Here are five ways President Donald J. Trump could spell doom for the planet.

1. Dismantle the U.S. Environmental Protection Agency

Trump said would get rid of the U.S. Environmental Protection Agency (EPA), the agency created in 1970 by President Richard Nixon that has become the nation's main federal lever for mitigating the impacts of climate change. "Environmental Protection, what they do is a disgrace," he told Fox News Sunday host Chris Wallace in October of last year. "Every week they come out with new regulations. They're making it impossible."

When Wallace asked him who would protect the environment, Trump replied, "We'll be fine with the environment. … We can leave a little bit, but you can't destroy businesses." During the GOP presidential debate on March 3, he hammered the EPA again, saying he would "get rid of [EPA] in almost every form. We are going to have little tidbits left but we are going to take a tremendous amount out."

But he has since backtracked, saying in September that he'll "refocus the EPA on its core mission of ensuring clean air, and clean, safe drinking water for all Americans." Still, his more moderate tone should offer little solace for environmentalists. Last month at a roundtable in Boynton Beach, Florida, he committed to cutting EPA regulations "70 to 80 percent."

The person currently running the EPA working group on Trump's transition team—and a leading candidate to become the agency's next administrator—is Myron Ebell, the director of energy and environment policy at the conservative think tank Competitive Enterprise Institute, who the Financial Times called "one of America's most prominent climate-change skeptics." Ebell, whose work has been funded by some of the nation's worst polluters, like Murray Energy, the nation's largest coal mining company, said, "I would like to have more funding [from big coal] so that I can combat the nonsense put out by the environmental movement."

2. Reopen Shuttered Coal Mines

Among all fossil fuels, coal is the dirtiest. When it's burned, it produces more pollution than oil, gasoline and natural gas. And though we burn 8 billion tons of coal every year to fuel around 33 percent of the nation's electricity generation, the industry has been slumping in the face of low natural gas prices and sluggish growth in electricity demand.

In January, the coal industry received a major blow when Interior Secretary Sally Jewell issued a federal moratorium on the issuing of new coal mining leases on public lands across the U.S. as her department conducts a review of the program, the first in more than three decades.

The death knell of the coal industry has been good news for environmentalists and renewable energy advocates, but a Trump regime may breathe new life into coal. One of his top candidates to replace Jewell is oil industry executive Forrest Lucas, co-founder of Lucas Oil. During his victory speech after securing the GOP presidential nomination in May, Trump said, "Let me tell you, the miners in West Virginia and Pennsylvania ... they're going to start to work again, believe me. You're going to be proud again to be miners."

While it is unlikely that President Trump can completely reverse the steady decline in coal jobs, which has taken place over decades, he can instruct his Interior Secretary to end Jewell's lease moratorium. He can reverse Obama's clean air and water initiatives that the coal industry views as job killers. He can push coal subsidies through Congress in the form of direct spending, low-interest loans and loan forgiveness, tax breaks and tax exemptions, and discounted royalty fees for the right to mine on federal land.

3. Pull the U.S. Out of Paris Climate Agreement

The U.S. is the world's second largest emitter of greenhouse gases after China. The nation's pledge to the Paris climate agreement, which aims to keep the global surface temperature increase to a maximum of 2 C to avoid the worst impacts of climate change, is to avoid 22 billion tons of carbon dioxide equivalent emissions between 2016 and 2030. That amounts to about a fifth of the total of all the nations that have signed the accord.

The problem with the Paris agreement is that it is a non-binding treaty; there is no punishment for nations that don't meet their carbon reduction target. In May, when Trump outlined his energy policy in a prepared speech in Bismarck, North Dakota, he castigated "draconian" climate rules, pledging to "cancel" the Paris climate agreement and withdraw funding for climate-related United Nations programs.

What would happen if Trump pulled America out of the accord, something he could technically accomplish in several ways?

"I think the rest of the world would be less likely to take action on their own part and do their own share," said Andrew Jones, co-director of Climate Interactive, a Washington, DC-based think tank.

4. Approve the Keystone XL Pipeline

Last November, following a seven-year review, President Obama rejected the controversial Keystone XL pipeline, which would transport crude oil from the oil sands in Alberta, Canada, through Montana and into Nebraska.

In August of last year, Trump tweeted, "If I am elected President I will immediately approve the Keystone XL pipeline. No impact on environment & lots of jobs for U.S." With Trump set to enter the White House in January, the pipeline plans have been resuscitated as TransCanada, the company behind the proposed 1,179-mile pipeline, announced plans on Wednesday to meet with the president-elect's camp. "TransCanada remains fully committed to building Keystone XL," Mark Cooper, a spokesman for the company, said in a statement emailed to the Huffington Post. After conducting environmental impact review, the U.S. State Department said it was likely that the pipeline, which crosses thousands of rivers and streams, including several major rivers like the Yellowstone and Platte, would experience spills.

"I want it built, but I want a piece of the profits," Trump said in May. "That's how we're going to make our country rich again."

5. Reduce Investment in Clean Energy

Speaking in November of last year in Newton, Iowa, Trump said "wind is a problem," calling it "a very expensive form of energy." However, the fact is that in some parts of the nation, like Texas and in particular Iowa—the state that generates the highest amount of wind power as a percentage of its total energy portfolio—wind energy is cheaper than coal or gas-powered energy.

According to projections by the U.S. Energy Information Administration, the average rate for new combined cycle natural gas-fired plants (which use both a gas and a steam turbine) going online in 2018 will be around $48 per megawatt hour (MWh). The agency said that the 2018 unsubsidized rate for onshore wind farms will be $51.9/MWh, but with subsidies, that rate drops to $34/MW—cheaper than gas.

Speaking in Fresno in May, Trump said, "I know a lot about solar. I love solar," but added that there are "a lot of problems with it. One problem is it's too expensive."

He's right on that front, as solar power is pricier than wind, with the U.S. Energy Information Administration projecting the cost for solar in 2018 at $71/MWh without subsidies and $53.5/MWh with subsidies. But abandoning solar installations today will stifle the downward trend in cost: Since 2011, the price of a solar panel has declined an impressive 60 percent.

Today, around 209,000 American workers fill solar-related jobs in more than 8,000 companies. That's more than double the number of solar workers in 2010. By 2020, the number of solar workers is expected to more than double, with 420,000 Americans employed in the industry. Government subsidies in solar, which was around $24 billion from 2014 to 2018, helped lower costs by at least 10 percent a year.

Together, wind and solar generate less than 5 percent of America's electricity. But renewable energy advocates argue that we have the technology to move the nation to 100 percent clean energy in the coming decades. "For the first time in human history, we're actually at a place, technologically speaking, where we can make this transition," actor/activist Mark Ruffalo told Mother Jones in 2014.

But Trump has signaled the opposite: investing more in fossil fuels and less in renewable energy. The biggest wind power tax credit has already expired, while the most important solar power tax credit is set to expire at the end of this year. Trump is unlikely to renew them.

Is There Any Hope?

Could President Trump surprise freaked-out environmentalists and be green? If we've learned anything this election season, it's not to be surprised by anything Trump says. On the campaign trail, has has shown he can change his views, for better or worse, or at least be fluid with them—when it suits his purpose.

In May, for example, Politico reported that the billionaire's application for permission to erect coastal protection at his seaside golf resort, Trump International Golf Links & Hotel Ireland, in County Clare, explicitly cited the consequences of global warming as the main justification for building the sea wall. The zoning application noted that the wall was necessary to protect the course from "global warming and its effects." And during the first presidential debate in September, Trump denied ever saying that climate change was a Chinese hoax (though his tweet saying that is still on his Twitter feed).

The fact remains that executive power is balanced by Congress and the Supreme Court. "Trump would find himself hemmed in by the built-in limitations on presidential power. One of these is Congress," said John Sides, an associate professor of public policy at George Washington University. "There are others—including divided government, bureaucratic inertia and public opinion. He would be no different than any other president in this respect."

Looking past the next four years, there is some promise: Young voters between the ages of 18 and 25 overwhelmingly voted for a non-Trumpian vision.

"I know the youth voted for the future that so many of us yearn for. A future where there is a greater sense of shared abundance and responsibility to one another, our nation and our planet," said John Horning, executive director of WildEarth Guardians, in an email. "This fills me with enormous hope. Without a doubt, the ushering in of Trump is belied by our future generations speaking loudly and clearly that they intend to bring forward a better world."

Time to Redouble Efforts

While the Trump presidency gives much to worry about when it comes to the health of the planet, many green leaders joined Horning in striking a hopeful tone, seeking to mobilize more action on climate change and the environment.

"Fear may have won this election, but bravery, hope and perseverance will overcome," said Annie Leonard, the executive director of Greenpeace USA. She called on those who didn't vote for Trump to "use this moment to re-energize the fight for the climate and the fight for human rights around the world."

Wenonah Hauter, the executive director of Food & Water Watch, called Trump's victory a "major disaster." In a statement, she said:

"Unsurprisingly, the Trump administration will likely be filled with people who will benefit financially from more fracking, more industrial agriculture and factory farms, and expanded deregulation masquerading as trade policy. The people he has indicated will be in his cabinet are the same people who have advocated policies that are destroying our climate and creating a society marked by stratification and racial prejudice."

But Hauter also offered a motivational spark, saying, "We must redouble our efforts to build a movement that holds our elected officials accountable—and that provides a counterweight to the big business interests that continue to look out only for profits."

That could mean working more on a local level, where the long arm of Washington, DC, doesn't reach, through state- or city-wide initiatives. On Election Day, for example, voters in Monterey County, California's fourth-largest oil-producing county, passed Measure Z to ban fracking. Golden State voters also narrowly passed Prop 67, which bans grocery stores and selected retail outlets from handing out single-use plastic bags. Voters in Alabama passed ballot measure SB260, a statewide amendment that will end the practice of spending revenues generated at state parks for purposes other than maintaining the parks. Plus, many cities and states will continue their own carbon emission reduction plans.

Environmentalists' Toughest Test

Donald Trump's most enduring legacy as president may be the lasting damage he does to the environment. If you're concerned about that, the next four years promises to be a rough ride, but now is the time to get involved in the fight for the health of the planet and all the creatures who call it home.

As Greenpeace's Leonard pointed out, "Millions of people around the world have all the power we need to combat climate change and create a just world for everyone." While she may be right, that sentiment is set to face its toughest test yet: The 45th president of the U.S.

Reposted with permission from our media associate AlterNet.