Property Lines is a column by Curbed senior reporter Patrick Sisson that spotlights real estate trends and hot housing markets across the country. Comments, tips, and suggestions on where Property Lines should head next are welcome at patrick@curbed.com .

Last week, climate change found many ways to inch into the news cycle.

In Washington, D.C., hundreds of young advocates protested at Congressional offices, demanding a Green New Deal. In central California, residents continued to try to make sense of the communities erased by the Camp Fire. In Paris, Yellow Vest protesters rioted in reaction to a planned increase in gasoline taxes, an effort the French president said is meant to combat rising emissions. In Katowice, Poland, representatives from across the globe gathered to craft a global consensus around cutting emissions at the COP24 talks.

With recent blockbuster reports highlighting the dire and immediate nature of climate change, the environment—and the politics and planning that come in response—seem unlikely to leave the spotlight anytime soon. The scope of economic, technological, and social change needed to grapple with climate change is unlike anything we’ve seen before, say advocates and activists. The Green New Deal, a nascent plan to invest in sustainable infrastructure and power generation, would be a “massive system upgrade for the economy,” according to Saikat Chakrabarti, chief of staff for Congresswoman Alexandria Ocasio-Cortez.

What would this type of sweeping change look like for U.S. cities? At a time when municipalities consider or enact climate action plans, two of the bigger urbanism stories of the last week—the passage of the Minneapolis 2040 plan, which will upzone the entire city, and a new effort to pass a statewide transit-oriented development proposal in housing-starved California—may, without meaning to, provide glimpses of what that kind of vision may resemble.

Both proposals seek, first and foremost, to address equity, especially housing affordability. But they also share a focus on increasing urban density, a reliable way to decrease emissions and improve the environment, and recognize that cities will be where the effort to curtail climate change is won or lost.

Climate risk is a challenge for nearly every city

Though cities would likely rather not, they stand on the front lines of the climate fight. Already, 70 percent of the world’s cities are dealing with the impact of a changing climate, according to C40, a global network of cities committed to combating climate change. And nearly every urban area faces significant risk, especially the 90 percent of coastal urban areas looking at a future of increased flooding and rising sea levels.

With this year expected to set a global carbon emissions record, advocates plead that there’s no time to delay ambitious plans and immediate action. A new report by the Global Covenant of Mayors bluntly states that “an incremental approach to adaptation will not suffice.”

The Intergovernmental Panel on Climate Change’s latest report says that absent concerted effort, cities like New Orleans and New York will face extensive flooding. Across the board, U.S. cities will face higher temperatures and the corresponding health issues they bring. As cities sprawl, there’s increased risk of wildfire damage: According to analysis by Montana-based Headwaters Economics, 60 percent of new homes built in the U.S. since 1990 sit within the “Wildland-Urban Interface area,” the liminal area that marks the division between unoccupied land and human development. The National Climate Assessment predicts hundreds of billions of dollars of climate-related damage, concentrated in cities, by the end of the century.

But in the face of this existential threat, cities also present the best places to curb emissions: Though urban areas generate 70 percent of the world’s carbon dioxide, that also makes them a good place to start making a difference. Toward a Healthier World, a report by the C40 network, argues that with a strict series of policy changes—including bolstering cycling, walking, and public transit; enacting more energy-efficient building codes and retrofitting old structures; and a rapid investment in renewable power—cities could achieve an 87 percent reduction in greenhouse gas emissions.

Is greater density the solution?

Environmental proposals face an uphill battle, as they often ask for great sacrifice to merely postpone climate change’s negative impacts—and often challenge entrenched, wealthy interests.

Research suggests that simply increasing density could be a place to start—and get cities much of the way toward their carbon emission-reduction goals. A 2014 London School of Economics study determined that large global cities, with a “modest blend of pro-density housing and transit policies,” could cut their emissions by a third by 2030. Urbanist Peter Calthorpe calculated that through urban densification alone, the United States could achieve half the carbon reductions needed to hold global temperatures to a rise of 2 degrees Celsius (4 degrees Fahrenheit).

More density also means more housing, especially along transit corridors and downtown near jobs. By reducing sprawl, adding more housing units, and, ideally, cutting down transit times, building density tackles a key side effect of rising costs: the movement of affordable housing farther away from opportunity.

“For too long we have created sprawl by artificially limiting the number of homes that are built near transit and job centers,” California state Sen. Scott Weiner told Curbed writer Adam Brinklow via email. “As a result of this restrictive zoning in urbanized areas, people are forced into crushing commutes, which undermines our climate goals.”

Placing density at the center of climate change mitigation strategy means not just doing the “right thing” in terms of cutting emissions, but offering tangible, immediate benefits as a selling point. Increased density means more opportunities for walkable neighborhoods and car-free transit, which would cut pollution. Density means shorter commutes and less driving, leading to less congestion, fewer road fatalities, and improved health outcomes from cleaner air.

These very issues—affordability, transportation, equity—have helped sell both the Minneapolis 2040 plan and Weiner’s transit-oriented development bill, SB-50, the More Housing, Opportunity, Mobility, Equity, and Stability (More HOMES) Act. Weiner’s bill is as much about transportation—now the fastest-growing source of carbon emissions in California, as well as the U.S at large—as it is about housing.

“If we have more people living closer to public transportation, so they’re not driving or [they are] driving less, it’ll give us a much better chance of meeting our climate goals,” Weiner told Curbed. “We’ll never meet them with current land-use patterns.”

Our climate future relies on concerted city action

As Minneapolis Mayor Jacob Frey has said, the Minneapolis 2040 plan isn’t just a housing plan, it’s also about infrastructure and transportation. Other cities and states have proposed larger zoning overhauls. In Massachusetts, Gov. Charlie Baker proposed a bill that would make it easier to upzone. It is currently stalled in the legislature. Seattle is attempting to upzone more of the city to accommodate its growing population; 13 percent of the city’s land area, which has been zoned for more density, has absorbed half of the city’s population increase since 2010.

To make significant impact on climate change, cities everywhere will need to play a part (much of the coming wave of urbanization expected across the globe will take place in the developing world). But as a country that has more resources—and has released more emissions—than any other, it’ll be hard to escape the argument that it’s incumbent on the U.S. to show some kind of leadership on this issue.

According to University of Pennsylvania professor Daniel Cohen, dense neighborhoods “anchored by both affordable housing and good access to transit” are the ones that manage to have lower carbon footprints.

Historian Mike Davis may have summed it up best in an article for the New Left Review: “the cornerstone of the low-carbon city is … the priority given of public affluence over private wealth.” As cities confront climate change, and decide what, if any, action they will take, the recent example set by Minneapolis may be more of a trendsetter than an outlier. Perhaps the desire to invest in climate action will spur changes that solve a host of other urban problems.