It doesn’t solve the problem to buy a hybrid and retrofit your house if all of that takes place 20 miles from your job

Researchers from the Lawrence Berkeley National Laboratory recently published a projection in the journal Science of what it would take for California, by 2050, to reach the state’s goal of cutting greenhouse gas emissions to 80 percent below 1990 levels. Their vision would make any environmentalist swoon: They see workers locking the door to their net-zero homes, hopping in battery-powered cars, then heading to uber-efficient offices powered by solar panels.

In the methodical build-up to this world, first buildings, lighting and appliances become more energy efficient. Then the energy sector shifts wholesale to renewable and cleaner sources. Then vehicles and heaters that today run on fuel will become electrified.

This vision sounds great, if not technically daunting. But it falls prey to a common assumption about how we’re going to address climate change: that we have to do it all with technology.

A significant – and seldom noticed – part of the solution lies with some fairly low-tech infrastructure: our houses, and the relationship they have to each other and where we want to go. A growing body of data has mapped the carbon footprint in sprawling suburbia of a single-family home, which is located nowhere near the grocery store, the job center or the shopping district. We can now compare that footprint to a multi-family home in a walkable urban neighborhood. And it turns out the gap between those two models may offer a serious – and perhaps more palatable – place to start thinking about the problem of climate change.

Proponents of this strategy aren’t talking about lithium-ion batteries, carbon capture and storage or smart grids. They’re talking about land use (and inviting to the climate change table urban planners who are seldom mentioned in the same breath as electrical engineers).

“It’s got to be the number one way we’re going to address both energy security and greenhouse gas emissions,” predicts University of Michigan professor and Brookings Institution senior fellow Christopher Leinberger. “And it is a structurally sustainable reduction.”

Other solutions, like increasing the efficiency of cars and appliances, have been shown in some research to have a perverse side effect: Give people a hybrid, and they drive more. Give people a state-of-the-art home heating system, and sometimes they turn up the temperature. But there’s no backsliding with land-use changes.

Some smart-growth advocates put this even more bluntly, suggesting that suburban lifestyles represent one of the most serious threats to the climate. Real estate developer and planner Jonathan Rose has done modeling that puts data to this claim, some of which is corralled in this chart from the Center for Clean Air Policy report “Growing Wealthier."

The chart underscores a growing realization among environmentalists: It doesn’t solve the problem to buy a hybrid and retrofit your house if all of that takes place 20 miles from your job. You’d still consume more energy (“suburban single family green”) than an urban household without the latest green tech (“urban single family”). And that has as much to do with associated transportation emissions as the size and efficiency of your home.

The implication is that if more suburbanites opted to move out of their low-density detached homes and into walkable, mixed-use urban communities (or if we retrofitted suburbia to better resemble such places), right there we’d be on our way to taking a real whack at carbon emissions.

We'd still need to increase the fuel standards of cars, and change the makeup of fuel itself. But what if we could also simply reduce the miles people drive by in a sense pushing their many destinations closer together?

“Engineers and economists say, ‘get the right technology, set the right price signals, and you’re done,’” says Steve Winkelman, one of the authors of “Growing Wealthier.” “I’ve been working in planning circles, and this is a lot messier. That’s why regulators don’t like it. Really, it’s much more of a planning approach, and people have to find their own self-interest in this to get to a [higher] penetration level.”

This messy approach, though, has several things going for it that technological solutions to climate change don’t. For one, urbanizing communities comes with a whole host of co-benefits: it saves people money on utility bills, it improves public health, it reduces congestion and improves air quality, and it may even make communities happier (as walkability has been shown to do).

The need to shift to low-carbon, denser living also parallels where the market is heading anyway. There’s no need to forcibly decamp suburbanites for inner-city condos. People are doing this anyway, with demand in particular growing for housing located near transit.

“I wish that 30-50 percent of people wanted to drive a hybrid, but that’s not whatever the couple-percent penetration is now,” Winkelman says. Many more people do, however, want to live in low-carbon communities (although most of them don’t put it that way). “Right here,” Winkelman says, “it’s clear that there’s unmet market demand.”

Peter Calthrope has taken some of these calculations even further, as part of California’s scenario planning for the state law that set those 2050 emissions-reduction goals. He's projected the impact of changes in housing stock and land-use planning into the year 2050, examining shifting ratios of supply for large-lot single-family homes, small-lot single-family homes, attached homes and multi-family apartments, under varying degrees of energy efficiency.

On the neighborhood level, an average household in a high-density urban San Francisco-area community produces 6 metric tons of carbon emissions a year from transportation and household heating. A single-family household in a nearby suburban area produces 21 metric tons. Like other practitioners, Calthrope concludes that we can’t get where we want to go in cutting emissions without bringing that second number closer to the first.

“There’s a lot of built cities that basically are not going to be able to change, and you have to do technological change,” says John Fregonese, a veteran planner based in Portland. “But that being said, this is important. If you’re going to live in a situation where energy use and carbon emissions are going to be important and something you want to reduce, the kind of community you build is really important.”

Like Calthorpe, Fregonese has been peddling this message to cities and states that now want to begin crafting master plans for regional land use decades into the future. California, Oregon, and Washington state are all at the forefront of this, as is, surprisingly, more conservative Utah. Communities there are beginning to get the connection between housing style, location, associated transportation and carbon emissions.

 “On the other hand, when we were working in Texas, we mentioned to one city that I won’t name that this downtown plan would reduce their greenhouse gas emissions by 20 percent,” Fregonese says. “And they said, ‘Don’t mention that, just don’t bring that up. Tell people they’re saving money.’”

This may be one of the best arguments in an era of fraught climate politics for land-use planning as a part of the solution: No one has to call it that. Especially not when market forces are heading this direction, too.

“Sometimes it really helps,” Fregonese says. “Sometimes you’re better off just to list the co-benefits.”

Photo credit: Reuters/Mike Blake

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