"The Paris agreement, even with the temporary absence of US leadership, will still be a critical factor in helping our children solve the enormous challenge in civilization," Obama said at a Seoul conference organized by South Korea's Chosun Ilbo media group.
President Donald Trump's decision to withdraw from the Paris climate agreement in June was criticized by some as shifting leadership
of global efforts to limit climate change to Asia. Trump said last month he was open to renegotiating aspects of the agreement -- which was inked under his Democratic predecessor and which all nations except two have signed onto.
In his speech, Obama highlighted the role China plays in allowing North Korean Supreme Leader Kim Jong Un's regime to continue.
"China is the one country North Korea does depend on to some extent and the elites depend on to access foreign currency, basic supplies that are important to the regime," the former president said.
Obama also noted that Kim governs a bit differently than his father who preceded him, but is still a threat due to his hunger for power.
"Pyongyang doesn't always listen to China," the former president said. "Unlike the father, the son often times has engaged in fairly significant diplomatic insults of Beijing in a way we haven't seen before and in a way that surprised China."
"You have a young man who is only interested in maintaining power and is willing to do anything to sustain that," Obama added.
Trump spoke alongside South Korean President Moon Jae-in Friday in the US, expressing his frustration with the North Korean government.
"The era of strategic patience with the North Korean regime has failed," he said
in a statement from the Rose Garden. "And, frankly, that patience is over."
After the speech in Seoul Monday, Obama and Moon met and discussed the future relationship between the US and Asia.
The US and China have been at odds recently over a $1.4 billion arms sale
to Taiwan, which Beijing regards as a renegade province, and after the US sanctioned China's Dandong bank for alleged ties to North Korea
. The US also labeled China as one of the world's worst countries for human trafficking
and challenged Beijing in the South China Sea, by sailing close
to a disputed island chain that China claims.