As Secretary of State John Kerry prepares to step down in less than two weeks, he has a lot of concerns about the impact of climate change. Kerry spoke at MIT on Monday. Despite his concerns, Kerry struck a sometime-optimistic tone. 

Kerry told a crowd at MIT that 2016 was the hottest year in recorded history. He described melting glaciers and spoke of rising sea levels and an increase in severe storms.

“And unless we take the steps necessary to change the course that our planet is on, the impacts that we have already seen will pale in comparison to what we will witness in years to come,” he said.

The question, he said, is whether the country can transition to clean energy sources in time: “We face resistance of a strange combination of doubters and people making a lot of money off today’s paradigm.”

While coal might seem like a cheaper option now, Kerry said, energy sources that contribute to climate change are far costlier in the long term.  President-elect Donald Trump, who has pledged to bring back coal jobs, has called climate change a hoax. And Trump’s pick to run the Environmental Protection Agency, Oklahoma Attorney General Scott Pruitt, has fought EPA regulations of greenhouse gases.

Kerry said climate change shouldn’t be a partisan issue. “It’s an issue that all of us should care about, regardless of political affiliation,” he said.

The outgoing secretary of state seemed hopeful the new administration will keep an open mind on the subject.

“I’m not going to speculate about the policies that the president elect and his secretary of state will chose to pursue," he said. "But I will tell you this: In the time I’ve spent in public life, one of the things I’ve learned is that some issues look a lot different when you’re actually in office, compared to when you’re on the campaign trail.”

Even if the Trump administration doesn’t take steps to reduce greenhouse gases, Kerry struck an optimistic tone as he looked forward.

“Today, I am confident that the United States is going to meet all of the emissions targets we that have set, not because of future government action, but because of the market-based forces that are taking hold all over the world," he said. "The energy curve is bending towards sustainability.”

In the U.S., Kerry said, more people are now employed in renewable energy than by either the petroleum or coal industries, while cities are taking crucial steps to reduce their climate impact. Boston Mayor Marty Walsh, who was in the audience for Kerry’s speech, said the new administration may cause Boston to intensify its efforts to reduce greenhouse gases.

“The White House can only set policy. It’s carried out by cities and industry," Walsh said. "And I think that whether or not the White House believes in it, as long as cities and towns and industry around America continue to move forward, that’s where the work is carried out anyway, regardless of what the policy is.”

In November, Walsh and 13 other mayors in the region pledged to eliminate their communities’ carbon footprint by 2050.