SAN FRANCISCO — It’s an audacious proposal to get Californians out of their cars: a bill in the State Legislature that would allow eight-story buildings near major transit stops, even if local communities object.

The idea is to foster taller, more compact residential neighborhoods that wean people from long, gas-guzzling commutes, reducing greenhouse-gas emissions.

So it was surprising to see the Sierra Club among the bill’s opponents, since its policy proposals call for communities to be “revitalized or retrofitted” to achieve precisely those environmental goals. The California chapter described the bill as “heavy-handed,” saying it could cause a backlash against public transit and lead to the displacement of low-income residents from existing housing.