This year, the Trump administration has made it clear that addressing climate change is not a priority. It’s repealing Obama’s Clean Power Plan, the 2015 legislation that would cut power sector emissions by an estimated 32% by 2030, and it intends to roll back fuel efficiency standards. Even if the administration kept those laws in place, they still wouldn’t be enough to meet the carbon emission reduction goals put in place by the Paris climate accord–which Trump plans to ditch in 2020, the first year countries can withdraw, anyway.
But a new study from the University of Pennsylvania and MIT suggests three strategies focused on our homes and cities to make up for all the laws Trump is cutting: change urban development patterns, make housing more energy efficient, and make cars more environmentally friendly.
“If you ask which end-use sectors are responsible for the most greenhouse gas emissions, the answer is housing and transportation,” John D. Landis, the crossways professor of city and regional planning in Penn’s School of Design, said in a news release. “These are two places where, if you wanted to take a regional approach to reducing greenhouse gases, you could. We wanted to see how far you could go.”
Landis and coauthors Erick Guerra and David Hsu of MIT examined ways to reduce energy consumption in two related areas: housing (since residential energy use accounts for 22% of energy consumption in the United States) and transportation (since 28% of greenhouse gas emissions are from transportation, and private cars and trucks account for 62% of transportation emissions). Their two primary research questions asked: “What is the potential for local residential energy conservation mandates to substantially reduce residential energy consumption and related CO2 emissions?” and “What is the potential for local infill and compact growth programs to reduce vehicle miles traveled, and thus transport-based CO2 emissions?”
In other words, can changing how–and where–we build housing stave off climate change apocalypse?
First, with respect to housing, the researchers set a baseline for how 11 metro areas from Los Angeles to New York consume energy based on the Energy Information Administration’s 2015 Residential Energy Consumption Survey. Then, they estimated how adopting energy-efficient design features–like efficient HVAC systems, efficient lighting, and more insulation, among other details–in new and retrofitted houses would reduce that aggregate power use, and thereby reduce carbon emissions from power plants. These changes alone could reduce emissions from the housing sector by 31% by 2030, “which isn’t all that much,” Landis tells Co.Design in an email.
Next, the researchers used data from the Texas A&M Transportation Institute to analyze development patterns and transportation behaviors in the 11 metropolitan regions. They concluded that changing land-use policies (like densifying through infill development, which is associated with more mass transit use and more walking) and transportation behaviors (like better mass transit) would only lead to marginal reductions in carbon emissions–since so many regions of the country are wholly dependent on driving. All in all, building cities more compactly and promoting alternatives to driving would only lead to a 10% reduction in emissions. However, pairing these efforts with fuel economy standards of 40 miles per gallon could lead to a 31% reduction in transportation-related carbon emissions by 2030.
The researchers point out that since projected population growth, the existing built environment, climate, and transportation infrastructure vary so much from place to place, there’s no one-size-fits-all approach that local governments can take to reduce carbon emissions. Their simulations concluded that residential conservation standards offered a lot of potential to reduce emissions since they’re scalable, cost-effective, and don’t receive very much local political backlash–unlike compact growth initiatives.
When Landis, Guerra, and Hsu began their study, they were interested in ways that local governments could supplement the Obama administration’s national climate change policy with local planning interventions. However, the study today takes on new meaning given the federal government’s focus on deregulation.
“If indeed the Trump administration steps completely away from its responsibilities to reduce CO2 emissions, thereby requiring state and local governments to take on a bigger role, those same government entities will have to get a lot better at using their regulatory, pricing, and investment powers to reduce auto dependency and residential energy use,” the study states.
One of the study’s final conclusions is that housing, land use, and transportation are all intertwined, complementary, and reinforcing. In order for planners to meaningfully combat climate change, they’ll have to view all three of these forces as a single system–and institute multidisciplinary policy changes that target them all.