Republican presidential candidate Marco Rubio (R-FL) asserted on Sunday that he was skeptical of human-induced global warming because there "never has been a moment" when the climate was not changing.

During an interview on Face the Nation, CBS host Bob Schieffer pressed the Florida Republican on whether he really believed that climate change could not be linked to human activities.

"What I said was that humans are not responsible for climate change in the way that some of these people out there are trying to make us believe for the following reason: I believe the climate is changing because there has never been a moment when the climate is not changing," he opined. "The question is what percentage of that -- or what is due to human activity?"

According to Rubio, attempts to address climate change were pointless because scientists could not prove that any solution would be worth the damage it did to the economy.

"If we do the things they want us to do -- cap and trade, you name it -- how much will that change the pace of climate change versus how much will it cost our economy?" the candidate asked. "Scientists can't tell us what impact it would have on reversing these changes. But I can tell you with certainty that it would have a devastating impact on our economy."

When Schieffer asked him about his opposition to LGBT rights, Rubio argued: "It's not that I'm against gay marriage, I believe the definition of the institution of marriage should be between one man and one woman."

"I don't believe courts should be making that decision, and I don't believe marriage is a constitutional right," he added. "I also don't believe your sexual preferences are a choice for the vast and enormous majority of people. In fact, the bottom line is that I believe that sexual preference is something that people are born with."