Coca-Cola's outgoing chairman Muhtar Kent is planning his retirement at a time when he sees running a global business becoming an even more difficult task.

"I think running a global business is getting tougher, it's getting harder. Not just the global competition, but also the sociopolitical dynamics around the world are making it harder, with more unknowns, more volatility — constant volatility," Kent told CNBC's Sara Eisen in an interview for "Closing Bell."

He listed Brexit, the U.S. trade wars and the falling value of emerging market currencies as several examples of political uncertainty. But he does not believe that volatility will disappear once the U.K. leaves the European Union and the U.S. strikes a trade deal with China.

"That's the world we live in, and that's going to be here to stay," he said.

While he sees more volatility as a challenge for leaders of global businesses, he also named two sources of anxiety for all CEOs.

"I think if there's two things that worry a CEO today and give them sleepless nights, one is the global war for talent and the second one is digitization," he said.

Coke announced on Thursday that Kent would retire in 2019, ending a 40-year career at the company.

Kent served as both chairman and CEO of the beverage company from 2009 to 2017. Current CEO James Quincey replaced him. Kent will formally pass over the reins as chairman to Quincey, his successor, after the company's annual meeting in April next year.

The entire interview will air on CNBC's "Closing Bell," beginning at 4 p.m. ET.