With the Democrats scrambling to come up with a legislative agenda after their November takeover of the House of Representatives, an old idea is making a comeback: a “Green New Deal.” Once the flagship issue of the Green Party, an environmental stimulus package is now a cause de celebre among the Democratic Party’s progressive wing.

While it looks like the party leadership isn’t too receptive to the idea, newly-elected Representative Alexandria Ocasio-Cortez has spearheaded legislation designed to create a “Select Committee for a Green New Deal.” The mandate of the proposed committee is ambitious, possibly to a fault. At times utopian in flavor, the committee would pursue everything from reducing greenhouse gas emissions to labor law enforcement and universal health care.

A recent plan from the progressive think tank Data for Progress is more disciplined, remaining focused on environmental issues, with clearer numerical targets for transitioning to renewable energy and reducing greenhouse gas emissions.

Yet in all the talk about a Green New Deal, there’s a conspicuous omission that could fatally undermine efforts to reduce greenhouse gas emissions: little to no focus is placed on the way we plan urban land use. This is especially strange considering the outsized role that the way we live and travel plays in raising or lowering greenhouse gas emissions.

According to the Environmental Protection Agency (EPA), transportation and electricity account for more than half of the US’ greenhouse gas emissions. As David Owen points out in his book “Green Metropolis,” city dwellers drive less, consume less electricity, and throw out less trash than their rural and suburban peers. This means that if proponents of the Green New Deal are serious about reducing carbon emissions, they will have to help more people move to cities.

One possible reason for this oversight is that urban planning in America isn’t a federal issue: it’s technically handled by states and administered by local governments. But when local urban planning is undermining basic civil liberties or degrading the environment, the federal government can and should step in.

Think of urban planning like education: most people agree that running schools should mostly be a local issue. Yet most people would also agree that federal interventions to desegregate local schools—against the wishes of local governments—were merited. More federal oversight over local land-use planning is wise for similar reasons: policies that enforce segregation and harm the environment don’t deserve federal deference.

So how should a federally-implemented Green New Deal approach land use? For starters, it could take on rules that only serve to reinforce car dependence and drive up the cost of urban housing. For example, take minimum parking requirements, which force developers to build more parking spaces than they otherwise would. In practice, these rules lead to greater dependence on personal automobiles and rising costs for housing in urban neighborhoods where land is scarce, which forces more people out of the city. The combined effect is higher greenhouse gas emissions.

Or take single-family zoning. These zones permit only detached single-family homes, prohibiting denser and more affordable housing types such as townhomes, duplexes, and apartments. Historically a tool of racial and economic segregation, single-family zoning today largely serves to force people into low-density, energy-hungry, auto-dependent neighborhoods. Encouraging cities to scrap these out-of-date policies—like Minneapolis did late last year—as a condition for any federal Green New Deal dollars could go a long way toward reducing carbon emissions.

Whatever your feelings on minimum parking requirements and single-family zoning, the least a Green New Deal could do is take on explicitly anti-environmental local rules. For example, a Green New Deal might require an end to local solar panel and wind turbine prohibitions as a condition for federal deductions and tax credits that mostly help the upper class, such as the mortgage interest deduction or the state and local tax credit. This type of preemption is already common at the state level and would help more people bypass regulatory barriers and transition to renewable energy.

While dismantling harmful local rules should be the priority, a Green New Deal could also help support proactive local environmental planning. Grants to cities interested in rebuilding their zoning ordinance or comprehensive plan to allow for walkable, mixed-use development patterns would do more than any federal infrastructure program to facilitate sustainable development. Getting deeper into the weeds, the federal government could also lend technical assistance to regional planning agencies like Metropolitan Planning Organizations (MPOs), as FEMA often does, to ensure that local planning offices are well-equipped to handle issues like wetlands and coastal management, incentivize efficient building standards, and maintain urban sewer and stormwater systems.

A Green New Deal that pours money into green infrastructure will ultimately fail if most Americans still can’t afford to live in a walkable neighborhood or install a solar panel on their roof. And merely ramping up federal environmental enforcement can only go so far while neglecting local governments, the front lines of building, flood, and sewerage regulation. If the Green New Deal can find its way into the busy Democratic agency in 2019, let’s hope it doesn’t forget about cities.