WASHINGTON – Sen. Marco Rubio will give the Republican response to President Obama’s State of the Union address next week, demonstrating the younger, more diverse face of the party as the nation confronts issues such as immigration.

But Rubio doesn’t think much of climate change, one of the other hot political topics of the moment. That puts the 41-year-old Rubio squarely in the anti-science wing of his party and among a shrinking number of Americans with doubts about global warming.

The Florida senator last week in an interview questioned whether “man-made activity” is contributing most to global warming, and he suggested there’s reasonable debate on whether there’s “significant scientific consensus” on the human role. He also questioned whether there’s anything the government can do to make a difference.

“When you look at the cost-benefit analysis that’s being proposed, if you did all these things they’re talking about, what impact would it really have on these changes that we’re outlining?” Rubio said during the interview with BuzzFeed. “On the other hand, I can tell you the impact it would have on certain industries and on our economy, and that’s where it falls apart.”

The Sierra Club in Florida issued a statement that oozed with incredulity. In recent years, extreme weather has “seriously damaged Florida’s infrastructure,” said Frank Jackalone, the staff director of Sierra Club Florida.

Already, local governments are developing regional plans to deal with rising seas, which are projected to make problems much worse along the Florida coastline. Studies show that Florida faces some dire consequences even with modest sea level rises.

They include saltwater intrusion into freshwater supplies, damage to infrastructure such as roads and sewer lines, and flooding that could force people to abandon beachfront property. Some studies show sea levels rising as much as six and a half feet over the next century, said Harold Wanless, chairman of the geology department at the University of Miami.

“We cannot afford to sit idly while the threat of climate change becomes a dangerous reality,” Jackalone said. “By denying the climate crisis and rejecting climate action, Marco Rubio’s got his head buried in the sand — and that’s a bad place to be when the seas are rising.”

A spokesman for Rubio, Alex Conant, said, “Sen. Rubio doesn’t think that big government can control the weather. But big government can hurt Florida’s economy and destroy jobs.”

There’s no doubt that fiscal matters, immigration and gun control are expected to take precedence in the coming months. Yet Obama almost certainly will address climate change in his State of the Union speech. Obama said last month in his inaugural address that Americans have a moral obligation to address the consequences of global warming, and he’s expected to offer more details Tuesday night.

Already, federal agencies are beginning to issue climate adaptation plans that outline what can be done to limit exposure of federal programs, assets and investments to the impacts of climate change, including sea level rise or more frequent or severe extreme weather. The Environmental Protection Agency warned in its preliminary adaptation plan that until now, the agency “has been able to assume that climate is relatively stable and future climate will mirror past climate.”

“However, with climate changing more rapidly than society has experienced in the past, the past is no longer a good predictor of the future.”