Sprawling, car-reliant suburbs have among the highest carbon emissions per household, while densely populated and transit-rich neighborhoods near city centers have among the lowest levels, according to the New York Times. Conventional wisdom suggests that greater population density translates to more walking, biking and public transit use, thus lowering carbon emissions from cars. But the relationship isn’t actually so straightforward, with local policies playing a major role, researchers say. That means decisions made today about city growth strategies will have ripple effects in the decades to come.

Enter activity centers. A Brookings Institution analysis indicates activity centers are spread across — and within — the country’s major metro regions, with most locals living within three miles of one. Officials in San Antonio; Boise, Idaho; Cape Cod, Massachusetts; and elsewhere are using activity centers as blueprints to create greener built environments.