Let’s just give up. That’s one way of responding to the reports that President Trump has decided to pull the United States out of the Paris climate accord.

After all, without the world’s largest economy and the second-largest emitter of greenhouse gases onboard, what point is there in any of us doing our part to try to prevent catastrophic climate change? Time to focus on yoga and juicing and what the kids today call “self-care.” Or maybe there’s a recreational drug that will make serial disasters seem exciting. Oh, and if you are really rich, it’s time to join the movement of high-end preppers and invest in some land on higher ground.

No, wait a minute, that’s . . . monstrous. Monstrous to people in Sri Lanka, where hundreds were killed in recent days in the midst of deadly mudslides and flooding. Monstrous to people in India and Pakistan, where thousands have died in heat waves in recent years.

Monstrous to the people in the United States who cannot afford to escape the worst impacts of storms like Sandy and Katrina, and whose homes and communities are already disappearing because of coastal erosion, from Alaska to Louisiana.

Today, I feel the same way about the urgency of climate action as I did yesterday: The threat is so grave that it is immoral to waste even a moment pondering our chances of success. So long as there is any chance of keeping temperatures below truly catastrophic levels, we have an unbreakable responsibility to do everything in our power to increase those chances.

"The threat is so grave that it is immoral to waste even a moment pondering our chances of success. So long as there is any chance of keeping temperatures below truly catastrophic levels, we have an unbreakable responsibility to do everything in our power to increase those chances."

And that means deploying every tool in the policy, activist and judicial arsenal to lower emissions. Since Trump has effectively turned the federal government into a subsidiary of ExxonMobil, from here on in, the rule of thumb needs to be: Every domain that he does not control needs to fully commit to being ExxonMobil’s worst nightmare.

Mayor de Blasio just announced that he plans to “sign an executive order maintaining New York City’s commitment to the Paris Agreement.” That’s good news. So is the ongoing investigation by New York’s attorney general into whether ExxonMobil misled shareholders about climate risks. And we need more examples like these.

Large states like New York and California need to commit to getting to 100% renewable energy as fast as current technology allows (and fortunately, that’s very fast). We also need states and cities to show that policies that decrease emissions don’t have to drive up prices or drive down employment; on the contrary, they can be designed to bring better, cheaper services and unionized jobs to those who are currently the most economically excluded.

Universities, faith institutions, foundations and trade unions need to use their endowments and pension funds to starve out the fossil fuel sector and bet big on clean energy.

And if Trump does indeed pull the U.S. out of Paris, Americans should prepare themselves for the possibility that other countries will impose trade and economic sanctions on the United States. This idea is gaining traction quickly, especially because Trump has been so quick to threaten economic retaliation against anyone who doesn’t follow his America-first dictates. It’s now much easier to imagine major trading partners responding to a Paris pullout by imposing penalties on U.S. goods, particularly those with a high carbon footprint.

This kind of tactic, if it went beyond threats, could have painful impacts on the U.S. economy. But it might provoke Trump to reconsider — and if he didn’t, it could cause him serious political damage with the very sectors where he made the most extravagant job-creation promises.

It’s difficult for any country to accept the idea that it might deserve (or even benefit from) outside economic sanctions. But consider this: The United States has imposed sanctions on others — South Africa and Iran are two examples — when it felt the moral case was clear and the stakes were high. It’s impossible to argue that an existential threat like climate disruption, and a rogue action like Trump’s, does not far surpass that bar.

Over the past four months, America’s allies have tried to use charm to get Trump to see the light on climate change. He has been cajoled by European and Chinese leaders. Canadian Prime Minister Justin Trudeau snapped a picture with Ivanka sitting behind her father’s desk in the Oval Office and even took her to the theater.

We now know that none of it worked. It’s time to communicate with this President in the only language he appears to understand: money.