Sen. Marco Rubio, R-Fla., speaks Tuesday at the National Press Club in Washington. (Molly Riley/AP)

Sen. Marco Rubio acknowledged Tuesday that climate change exists but questioned whether current legislative proposals could stop it.

Days after he attracted attention with controversial comments about the environment, Rubio (R-Fla.) fielded questions at the National Press Club and said that although climate change is a reality, he doesn’t see a solution in existing legislative proposals.

“Headlines notwithstanding, of course the climate is changing,” he said. “The climate is always changing, and that is a measurable that you can see. There is climate change.” He added: “The issue is whether there is legislative proposals before us that can do anything about it. What I have said and what I disagree with is the notion that if we pass cap and trade, it will stop this from happening.”

In an interview with ABC News on Sunday, Rubio said he thinks the impact of man-made climate change is being overstated — remarks that some interpreted as a denial that global warming is occurring.

“I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it,” he said in the interview.

Former vice president Al Gore, speaking at the Chicago University Institute of Politics, voiced a skeptical and at times sarcastic response to the stances of Senators Rand Paul (R-Ky.) and Marco Rubio (R-Fla.) on climate change. (Video courtesy University of Chicago's Institute of Politics)

Those comments sparked outrage on the left, and audience members at the National Press Club asked Rubio about them three times.

“There are things that we can do to become more efficient in our use of energy, there are things we can do to develop alternative forms of energy, there are things we can do to become better stewards of the energy resources that we have,” Rubio said. “But for people to go out and say, ‘If you pass this bill that I am proposing, this will somehow lead us to have less tornados and less hurricanes,’ that’s just not an accurate statement, and that’s what I take issue with.”

Rubio’s expansion on his previous remarks about climate change, as well as responses about the 2016 presidential contest and immigration reform, came after he delivered a speech on Social Security during the luncheon.

The senator, who has drawn scorn from some of the most conservative members of the GOP for backing comprehensive immigration reform, doubled down on the sentiment that the immigration system is broken.

Top Republicans in the House signaled earlier this year that they would be willing to bring a comprehensive immigration reform package up for a vote, but they quickly faced backlash from conservatives who said that passing changes that include a pathway to citizenship would doom the GOP during this year’s midterm elections.

House Republicans have since signaled that immigration reform probably won’t come up for a vote this year.

The senator declined to speculate whether the House would pass comprehensive immigration reform this year but said he is glad that he championed the cause — despite the political blowback.

“I regret that we didn’t get more support for it, because it’s an important issue that we’ve got to tackle,” Rubio said. “For this country to move forward in the 21st century, it needs to solve this . . . as a sovereign country and for our national security we need to have immigration laws we can enforce. And we need to address that we have 12 million people living in this country illegally. And we have to address it in a way that’s responsible and reasonable.”

In the speech, Rubio called for overhauls to both the Social Security and Medicare systems — including an elimination of the Social Security payroll tax, allowing public enrollment in the same government savings plan provided to members of Congress, and slowly raising the retirement age.

“The answer is to gradually increase the retirement age for future retirees to account for the rise in life expectancy,” Rubio said. “And if we act soon, we can do this without changing the retirement age for people who are currently over the age of 55.”

The speech was the latest in a series of policy addresses by Rubio, who is attempting to strengthen his policy credentials as he ponders a 2016 presidential run.

Asked about his presidential ambitions, Rubio said that if he seeks the GOP nomination, he will not simultaneously seek re-election to the Senate. He said he will not base his decision about whether to run on what former Florida governor Jeb Bush decides to do.

Rubio also showcased a more playful side, joking that he hopes Senate Majority Leader Harry M. Reid (Nev.) becomes the Democratic presidential nominee in 2016 and that, if elected president, he would invite Vice President Biden to the White House for a beer summit.

“He always tells good jokes,” Rubio said of Biden.