By Michael Kohn in Ulaanbaatar Two decades ago, Sumiyabazar Dolgorsuren was battling opponents on the wrestling mat as an Olympic athlete. Now he spends his days trying to put a stranglehold on Ulaanbaatar’s traffic and air pollution problems as mayor of the Mongolian capital. While his wrestling career is over, Sumiyabazar is still taking on challenges that result in both wins and losses. He’s credited with improving parks and open spaces, but has been blamed for the increasingly intolerable traffic. There is a lot riding on his success. The population of Ulaanbaatar has nearly tripled in the…