Climate change might be one of the world's "hardest problems to solve," but President Barack Obama says he is determined to establish policies that will help the United States to reduce its ecological footprint, and that making difficult political decisions can bring long-term payoff.

In a wide-ranging interview with VICE founder Shane Smith, Obama said climate change is among a cluster of key issues he's determined to tackle before he exits the White House in 2017.

"When I leave this office, I want things to be a little bit better," he said. "The longer you're in the job, the more you're likely to take the long view."

Obama outlined his key policy goals on the environment for the coming months, including gaining commitments from China to curb its greenhouse gas emissions ahead of the global climate summit in Paris at the end of this year, in addition to making appliances more efficient, and doubling both fuel efficiency standards and the production of clean energy.

He says he has his work cut out for him.

"The hardest thing to do in politics and in government is to make sacrifices now for a long-term payoff," he said. "There's always going to be resistance to change, and some of that is going to be generational. I guarantee you that the Republican Party will have to change its approach to climate change because voters will insist upon it."

Not only are Republican lawmakers resisting action on climate change, but some continue to deny the science and evidence, he said. This antagonism — the kind that has senators throwing snowballs on the Senate floor — has further seeped into other areas of legislation, becoming a damaging characteristic of gridlocked government in recent years.

"A sizeable portion of their party deny [climate change] even exists," Obama said**.** "Right now, on a lot of the issues young people care about, it's not both sides arguing and creating gridlock — you've got one side that is denying the facts."

How to combat the partisanship and obstruction? Vote, said Obama, adding that young people cannot afford complacency.

**"**The fact of the matter is that in the last election, a third of the eligible voters voted," Obama said. "And so if you've got gridlock and you've got people that aren't producing… that's a consequence of everyone staying home and acting cynical. And the minute that you withdraw in that way from the process of politics, well then you're destined to have existing power structures call the shots."

But there is one area that is seemingly beginning to rise above Congress' wrangling, and that's the issue of marijuana legalization. Nationwide, it is estimated that a taxed and regulated marijuana industry could take in some $10 billion for the government in coming years. It's also not just the money that has lawmakers from both parties interested, but also freewheeling public opinion that's rolling ever closer toward legalization.

"You're starting to see not just liberal Democrats, but also some very conservative Republicans recognize [prohibition] doesn't make sense, including sort of the libertarian wing of the Republican Party," Obama said.

"They see the money and how costly it is to incarcerate," he added. "So, we may actually be able to make some progress on the decriminalization side."

Yet for the government, domestic and international issues remain riddled with partisan politics. An example of this turmoil came earlier this month, when 47 Republican senators signed an open letter to Iran's supreme leader in an effort to undermine Obama's efforts to secure a deal to halt the Islamic Republic's nuclear program. The letter warned that any deal signed with Obama's administration would not last beyond his second term in the oval office, sparking a rift in public opinion, with some siding with the senators and others who coined the hashtag #47traitors.

The president responded last week by telling VICE News that he is "embarrassed" for the senators, among them the entire Republican Senate leadership, including potential 2016 presidential candidates Ted Cruz (Texas), Marco Rubio (Florida), and Rand Paul (Kentucky).

"For them to address a letter to the ayatollah — the supreme leader of Iran, who they claim is our mortal enemy — and their basic argument to them is: don't deal with our president, because you can't trust him to follow through on an agreement... That's close to unprecedented," he told VICE News.

Other areas of Middle East policy at the center of contention between Republicans and Democrats include how best to handle the growing global threat posed by the so-called Islamic State — also known as ISIS or ISIL — the Sunni Muslim militant group that has violently seized vast masses of land in Iraq and Syria and established a so-called caliphate over territory it controls.

The US response so far has been to lead a coalition of 60 member states in conducting airstrikes, while training and arming security forces and moderate militia in both of those countries.

Obama told VICE News he is "confident" the coalition will "slowly push back ISIL out of Iraq." But even after a potential defeat of the militant group, when the smoke clears, the threat of instability remains, via a new generation of disaffected youth — particularly Sunnis — in the Middle East and parts of northern Africa. This is why foreign aid investment to make those societies "responsive and functional" to their youth must be prioritized, he said.

"We can't keep on thinking about counterterrorism and security as entirely separate from diplomacy, development, education — all these things that are considered soft, but in fact are vital to our national security, and we do not fund those," Obama said. "We should be thinking about making investments there that ultimately save us from having to send our young men and women to fight or having folks come here and doing great harm."