President Obama answering questions at a town hall on MTV in 2010. (KEVIN LAMARQUE/REUTERS)

There’s a “huge contrast” between the two presidential candidates, on the “critical issue” of global warming – an issue that was noticeably missing from all three presidential debates, President Obama told MTV correspondent Sway Calloway Friday.

 "This is an issue that future generations – MTV viewers – are going to have to be dealing with even more than the older generation is,” Obama said, scoring a bullseye during a live interview from the Blue Room of the White House.

“This is a critical issue – and there's a huge contrast in this campaign between myself and Governor Romney. I'm surprised it didn't come up in the debates."

 “[Romney] says he believes in climate change...but he says he's not sure man-made causes are the reason," Obama said, adding, "I believe scientists, who say we're putting too much carbon emissions into the atmosphere and it's heating the planet and it’s going to have a severe effect."

 With polls showing a very tight race in swing states, President Obama took his campaign to Viacom-owned cable net MTV Friday for a live Q&A.

 MTV noted 45 million 18-to-29 year olds are eligible to vote this election – a target age bracket of the network.

 Obama won the ‘08 election by more than 30 points in that age group.

 For the half hour special, MTV took questions from young viewers via its Facebook page, and some submitted by a handful of students hanging out at Georgetown U. with MTV star Andrew Jenks.

 On Tuesday, when it announced the special, MTV had forecast Obama would get questions about jobs, the cost of college, rising student loan debt, and social issues like LGBTQ rights – which, MTV said, are the issues on the minds of MTV’s target audience.

 And, by gum – MTV was right!

 Trying to “to legislate federally” on same-sex couples' marriage rights is “probably the wrong way to go,” Obama told Sway, in answer to a question on that subject, adding that courts are examining these issues, and reminding Sway of  his opposition to the Defense of Marriage Act.

 “Ultimately, I believe that if we have that conversation at the state level, the evolution taking place in this country will get us to a place where were going to be recognizing” same-sex marriages.

 “What is really going to change this is young people – their attitudes are going to reflect the future, instead of the past,” he said.

 Mostly no new ground was covered – unless you count Sway’s suggestion that student loan debts be forgiven for those students who, upon leaving college, become entrepreneurs – like Facebook co-founder Mark Zuckerberg, Sway said.

( Zuckerberg famously dropped out after his sophomore year at Harvard.)

 Obama declined to endorse that plan (to his credit, he also declined to point out Zuckerberg could afford to pay off any student loan he might have taken out, several times over). Obama suggested instead that the way to go is to reward colleges and universities that work to reduce tuition cost, and cut federal aide to those that don’t, as well as keeping down down the interest rates on student loans, etc.

 The interview was a regular love fest, until Sway wondered what music artists Obama feel are upholding the tradition of Bob Marley, Bob Dylan, Rage Against the Machine and others, who made music that “inspired and informed.”

 “We haven’t seen as much directly political music,” Obama said, looking slightly out of his element and giving every indication he was about to punt.

 “I think the most vibrant musical genre over last 10 to 15 years has been hip-hop,” he continued, punt-ily.

 “Some folks have kind of dabbled in political statements, but a lot of it has been more cultural than political,” Obama continued. 

 Then he started talking Bruce Springsteen, and saying things like,  “I remember when I was in college, listening to Bob Marley,” and while not  agreeing with Marley’s “whole philosophy, necessarily,” having his awareness raised of “how people outside our country are thinking about the struggle for jobs, and dignity, and freedom.”

 He began to babble about how he;d like to see a more explicit discussion of political issues in music now, because young people “communicate in a lot of different ways” and “everything moves so fast today, you can set the world on fire in a positive way through a message that goes through the internet” and how he “had to go buy and album or a cartridge.”

 “Cartridge. Wow!” Sway said, and, taking pity on the old man, added, “I’ll send you some music you should tune into.”

 “…some music –  like Roots... and when I talk to them they’re doing some good stuff,” Obama continued, in a panic, explaining he’s been pretty busy the past four years — too busy to update his iPod.

 “I’ll hook you up,” Sway said, reassuringly.