Obama had a two-hour private lunch with Macron at the presidential Elysee Palace on Saturday. The area was placed under high security.
The French presidency said the meeting was expected to include a presentation about the Obama Foundation. No journalists were allowed at the meal.
Obama also met with former French President Francois Hollande, who said in a tweet that climate change was among the issues they discussed almost two years after they both signed the Paris agreement.
U.S. President Donald Trump has threatened to withdraw the United States from the agreement on reducing greenhouse gas emissions.
"We are confident the Paris agreement will be implemented," Hollande tweeted.
Obama mentioned climate change during his evening speech organized by a club for leaders from the internet and communications industries was on the theme, "Fear Less, Innovate More."
In a clear reference to his White House successor's threat, he remarked on the "absence of American leadership on the issue," making the audience laugh.
"But despite that, you're seeing American companies and states and cities continuing to work on this issue," Obama said.
The former two-term president said he is convinced the United States can fulfill its commitment to reduce emissions through actions outside of Washington.
Earlier Saturday, Obama also discussed climate issues with Paris Mayor Anne Hidalgo.
Obama was in China and India before he arrived in France.
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