By Michael Brenneis
The Biden administration, in accordance with the Paris Agreement, targets a 50% reduction of greenhouse gas emissions by 2030 in order to avoid the most damaging effects of climate change. Because it contributes almost 30% of GHG emissions, the transportation sector is a ready focus for transformation. Reducing the amount people drive, increasing the use of transit, building better infrastructure for people to safely walk and bike, and electrification are common goals. But changes to land use policy are often missing from this equation. To this end, the researchers at the Rocky Mountain Institute have begun to examine how changing land-use patterns might help curb GHG emissions.
Their study compares a “business-as-usual” growth scenario in three test cities—all dominated by the recent growth of single-family housing on the periphery—to an alternative scenario focused on the following:
- Upzoning: allowing duplexes and multiplexes in areas currently zoned for single-family housing.
- Infill: converting vacant lots, warehouses, and other light industrial sites to 3- to 5-story mixed-use, and
- Transit-oriented development: allowing 5- to 8-story mixed-use development within one-half mile of light rail, and within one-quarter mile of quality bus service.
These reforms reduce vehicle miles traveled and transportation emissions considerably, as shown below. The reforms also deliver other energy efficiencies such as those found in shared or connected housing.
The researchers conclude, however, that land use reform alone will not meet the goal of 20% VMT reduction per capita by 2030—the drop RMI calculates is necessary to limit warming to 2.7°F (1.5°C). The authors point to a list of additional essential reforms, including clustering destinations and housing to reduce trip length and make transit more attractive, building better walking and bicycling infrastructure that increases walkability, reforming parking policy including an unbundling from housing, trading driving lanes for express bus service, and shifting investments from road capacity to transit and maintenance.
Reformed land use and building practices can have additional environmental benefits beyond reducing emissions, which include reserving undeveloped land for other uses such as agriculture, green space, and habitat; reducing water consumption; and maintaining bio matter that functions as a natural carbon sink.
Researchers are finding that not only does upzoning, infill, and TOD reduce our contribution to global warming, it’s better for our general health and safety. A recent study from Dublin, Ireland, even linked living in a walkable neighborhood to an increase in happiness for many who live there.