Bloomberg's sit-down with the new Yahoo News global anchor, which debuted Friday, was his first major interview since leaving office in December. In it, he addressed climate change, gun control, education and income inequality.
On his support of charter schools, Bloomberg said "everyone forgets" that they are public schools.
"Charter schools have delivered superior educational results to a group of people who desperately need them and have been left out for far too long by the traditional methods," he added.
His successor, Bill de Blasio, last month prevented three charter schools from using space with traditional public schools under leases approved by Bloomberg's administration.
Bloomberg also touched on his controversial ban of large sugary drinks and said he expects to "win that battle" in court.
On de Blasio's decision not to march in the St. Patrick's Day parade because of it doesn't allow gay and lesbian groups to carry signs identifying themselves, the former mayor said "boycotting it doesn't get it done."
He supports gay rights and agreed the parade policy was misguided but said "that's just not the way I would do it." However, he said he respected de Blasio's decision, adding "he's the mayor.
He criticized President Barack Obama's effort to raise the minimum wage, calling it "one of the most misguided things we can do." He said an increase in the earned income tax credit, which Obama also supports, was the way to go.
Bloomberg was appointed the United Nations special envoy for cities and climate change in January.