Environmentalism has never been a stable ideology, and its adherents have never been a monolithic group. But, in Minneapolis, the green community has fractured as a wide array of self-described environmentalists find that they don’t agree on very much anymore. Back in 2018, Minneapolis generated national headlines for being the first major American city to eliminate single-family zoning. Under a plan called Minneapolis 2040, the city legalized duplexes and triplexes in all residential neighborhoods. The plan led to a frenzy of ambitious regulatory changes meant to yield denser, transit-accessible, and more affordable homes across the city. The stated goals of Minneapolis 2040 included housing affordability and racial equity, but supporters also stressed the environmental benefits of funneling population growth toward the urban core instead of outlying counties. “All the evidence and data shows that when you reduce your carbon footprint by, for instance, not having a 45-minute commute in from the suburbs … it helps the environment,” Minneapolis Mayor Jacob Frey told me at a downtown ice-cream shop in September. “It’s really simple, right?” Maybe. …