Portside

For progressives, Donald J. Trump’s presidency so far has been a little like standing in front of one of those tennis ball machines — and getting hit in the face over and over again. Yet looking back, the blow that still has me most off-kilter didn’t come from the new president himself. It came two weeks ago, when several smiling union leaders strolled out of the White House and up to a bank of waiting cameras and declared their firm allegiance to President Trump.

Sean McGarvey, president of North America’s Building Trades Unions, reported that Mr. Trump had taken the delegation on a tour of the Oval Office and displayed a level of respect that was “nothing short of incredible.” Mr. McGarvey pledged to work hand in glove with the new administration on energy, trade and infrastructure, while one of the other union leaders described the Inaugural Address as “a great moment for working men and women.” When Mr. Trump issued executive orders to smooth the way for construction of the Keystone XL and Dakota Access pipelines, the same leaders rejoiced.

A new administration can always count on many organizations to issue pro forma statements expressing a nonpartisan willingness to work with the new leader. Let’s be clear: This was not that. This was a new alliance. As Terry O’Sullivan, head of Laborers’ International Union of North America, put it on MSNBC: “The president’s a builder. We’re builders.”

But the edifice that Mr. Trump is building is rigged to collapse on the very people these unions are supposed to defend. His cuts to regulations will make them less safe on the job, and he may well wage war against the National Labor Relations Board, an agency that recently ruled that Mr. Trump violated the rights of the workers in his Las Vegas hotel to unionize and bargain collectively. His proposed cuts to corporate taxes will eviscerate the public services on which they depend, not to mention public sector union jobs. He supports “right to work” legislation that poses an existential threat to unions. His pick for labor secretary, the fast-food magnate Andrew Puzder, has a long record of failing to pay his workers properly, and he has praised the idea of replacing humans with machines

And Mr. Trump’s nominee for the Supreme Court, Neil Gorsuch, has ruled in favor of employers far more frequently than workers.

Indeed, the more cleareyed unions are openly questioning whether their organizations will survive this administration. The Labor Network for Sustainability, in a report, warns this could be “an ‘extinction-level event’ for organized labor.”

All this is an awful lot of ground to lose in exchange for mostly temporary jobs repairing highways and building oil pipelines.

And it’s worth taking a closer look at the implications of those pipelines, along with the rest of Mr. Trump’s climate-change denying agenda. A warming world is a catastrophe for the middle and working classes, even more than for the rich, who have the economic cushions to navigate most crises. It’s working and precariously unemployed people who tend to live in homes that are most vulnerable to extreme weather (as we saw during Hurricane Katrina and Superstorm Sandy) and whose savings, if they have any, can be entirely wiped out by a disaster.

It’s natural to ask: In times of insecurity, why shouldn’t unions worry more about jobs than about the environment? One reason is that responding to the urgency of the climate crisis has the potential to be the most powerful job creation machine since World War II. According to a Rockefeller Foundation-Deutsche Bank Climate Change Advisers study, energy-efficient retrofits in United States buildings alone could create “more than 3.3 million cumulative job years of employment.” There are millions more jobs to be created in renewable energy, public transit and light rail.

Moreover, a great many of those jobs would be in the building trades — jobs for carpenters, ironworkers, welders, pipe fitters — whose union leaders have been so cozy with Mr. Trump. These unions could be fighting for sustainable jobs in a green transition as part of a broad-based movement. Instead, they are doing public relations for the mostly temporary jobs Mr. Trump is offering — those building oil pipelines, weapons, prisons and border walls, while expanding the highway system even as public transit faces drastic cuts.

The good news is that the sectors that have made common cause with Mr. Trump represent less than a quarter of all unionized workers. And many other unions see the enormous potential in a green New Deal.

“We must make the transition to a clean energy economy now in order to create millions of good jobs, rebuild the American middle class, and avert catastrophe,” George Gresham, president of 1199 S.E.I.U., the largest health care union in the nation, said in a statement two days after Mr. Trump’s pipeline executive orders.

Other unionized workers, like New York’s Taxi Workers Alliance, showed their opposition to Mr. Trump’s travel ban by refusing fares to and from Kennedy Airport during the protests.

For a long time, these different approaches were papered over under the banner of solidarity. But now some union heads are creating a rift by showing so little solidarity with their fellow union members, particularly immigrants and public sector workers who find themselves under assault by Mr. Trump.

Today labor leaders face a clear choice. They can join the diverse and growing movement that is confronting Mr. Trump’s agenda on every front and attempt to lead America’s workers to a clean and safe future.

Or they can be the fist-pumping construction crew for a Trump dystopia — muscle for a menace.

Naomi Klein is the author of “This Changes Everything: Capitalism vs. the Climate” and “The Shock Doctrine.”