It’s no exaggeration that Donald Trump is setting up the most anti-environmental administration in American history.

As president-elect, Trump has nominated fossil fuel lobbyists and executives for key energy and environmental cabinet positions. His EPA administrator nominee, Oklahoma Attorney General Scott Pruitt, led the fight against the Clean Power Plan and other important EPA environmental and climate protections. Trump’s secretary of state nominee, Exxon Mobil CEO Rex Tillerson, literally aligns the most powerful fossil fuel corporate interests with federal foreign policy priorities.

As a candidate, Trump bizarrely said the climate crisis was a “ hoax” and that he would double down on fossil fuel development. He pledged to reverse President Barack Obama’s landmark climate policies achievements by derailing the Clean Power Plan, which set the first-ever limits on carbon pollution on power plans, and by withdrawing the U.S. from the breakthrough United Nations climate accord.

According to the scientific community, Trump’s dangerous energy policies come at the worst time for our climate, when we must take bold and ambitious actions to transition from dirty fossil fuels to a 100 percent clean energy-powered economy as soon as possible.

So how should we respond to the Trump climate crisis?

​The first step is to mount sustained and vocal political resistance to Trump’s extreme agenda. This means insisting that the Senate reject misguided cabinet nominees like Pruitt and Tillerson. Mainers should pressure Sens. Susan Collins and Angus King not only to vote no on these nominations but also to lead the fight against these nominees. Mainers should also demand that our congressional delegation defend our nation’s clean air and water safeguards and laws against all legislative and administrative attacks.

We cannot, however, afford to play defense only for the next four years. The truth is that Trump cannot prevent states, cities and towns from advancing the clean energy economy and sustainable policies. And while he can slow it down, Trump cannot stop the clean energy revolution driven by dramatically lower costs for solar, wind, efficiency and other smart energy technologies.

On the state level, in 2017 legislative session Mainers will have the opportunity to protect the right of citizens to generate — and be fairly compensated for — our own solar power. Mainers should call on their local representatives to pass an anticipated pro-solar bill and, if necessary, override a veto by Gov. Paul LePage.

Perhaps the wisest strategic action is to focus on making progress in Maine towns and cities. In response to LePage’s re-election, Sierra Club Maine launched a local Climate Action Team program to help citizens organize with their neighbors around town-based climate solutions like community and municipal solar projects, energy efficiency, waste reduction and more.

The Sierra Club’s Climate Action Team program is now active in Kezar Falls, Bath, Dover-Foxcroft, Brunswick, Portland, Bangor, Phippsburg, Bath, Cumberland, Freeport, Norway and South Paris. These grass-roots efforts not only improve their communities but they also provide models for other towns and build public support for statewide solutions. And we have found that taking local action empowers people and gives them much needed hope during times when many of us feel powerless and in despair.

During the next four years, it will be worth remembering that the majority of Americans did not vote for Trump. They rejected him for many reasons​ — and one of these reasons was his profoundly dangerous and ill-informed environmental positions. Trump cannot legitimately claim any mandate for such policies.

It’s true that we are in uncharted territory with Trump. But I take strength from the fact that we successfully blocked George W. Bush’s dirty energy agenda. On taking office, President Bush proclaimed that he wanted to build hundreds of new coal-fired power plants, but a grass-roots coalition of environmental justice and climate activists rose up to defeat 186 of them, one by one. Now, dirty coal is in serious decline, clean solar power is booming and the U.S. is part of a science-based global climate treaty.

We understand that Trump’s administration and an extreme Republican congressional majority are likely to cause real harm, but by building broader and more diverse coalitions and through bold grass-roots action, we will ultimately defeat Trump’s backward-looking energy and environmental policies.

Glen Brand is the director of the Sierra Club Maine.