Former president Barack Obama jokingly congratulated himself Tuesday for strong employment numbers in the U.S. this year during an address to a global conference of mayors convened in Chicago to discuss climate change.

"As we took these actions, we saw the U.S. economy grow consistently. We saw the longest streak of job creation in American history by far, a streak that still continues by the way," Obama told attendees of the North American Climate Summit Chicago, referring to clean energy priorities and carbon pollution regulations he introduced during his two terms in the White House.

"Thanks, Obama," the former president quipped, quoting a meme used by his supporters and opponents alike throughout his time in office.

Job growth recovered in October after hurricanes hindered progress the month before, the Bureau of Labor Statistics employment report showed in November.

Obama made the remarks before the group of mayors from around the world while arguing that rising temperatures can have run-on effects that impact national security and economic stability.

He said it was "an unusual time" for American leadership since President Trump announced a U.S. withdrawal from the Paris climate accord in June, adding "it was a difficult position to defend."

"But the good news is that the Paris Agreement was never going to solve the climate crisis on its own," Obama said, saying national governments can set goals, invest in alternate energy research, and incentivize market responses.

The centerpiece of the conference was the signing of the Chicago Climate Charter, designed as a substitute to the Paris deal, by the mayors present.

Obama praised the local leaders for their contribution.

"That's a powerful signal to the world, that's what leadership means, and it will make a difference," he concluded.

Many scientists believe climate change is caused by the burning of fossil fuels, along with other human factors, and that it is subsequently causing the planet to experience warmer weather.