Sustainable Cities

The September 2018 landmark IPCC report warns that over 1.5C of warming above pre-industrial levels will cross planetary tipping points that cannot be reversed. Our goal is to reach carbon neutrality by 2050, which requires halving global carbon emissions by 2030. Innumerable scenarios can be modeled with different pathways for achieving these targets by 2030 and 2050. We’re relying on the Exponential Climate Roadmap released alongside the IPCC report because it is comprehensive, science-based, and backed by the UN. 

We believe that supporting action at the city scale can play a role in reaching these goals as cities contribute up to 75% of global carbon emissions, with transportation and buildings being among the largest contributors. We are tracking progress in the 100 largest U.S. cities as defined by the population of the Metropolitan Statistical Areas (MSAs) in Census data. 

50% of commuter trips are by transit, walking, or biking by 2030 

Currently 73% of global emissions from the transportation sector come from cars, motorbikes, buses, and trucks making short journeys mainly in and around cities. 

We know that every vehicle on the road must be electric to meet our 2050 climate goals, but we also know that reducing vehicle miles traveled in private cars is an important part of the equation. Getting more people in US cities to walk, bike, and take transit is essential for reaching our climate goals and creating an equitable transportation system that does not require people to own a personal vehicle to meet their basic needs.

Based on 2019 data, there are 3 U.S. cities where over 20% of the workforce commutes to work by transit, walking, or biking. Another 11 cities are over 10%, but the remaining 86 largest U.S. cities are currently below 10%. 

No new fossil fuel use in buildings by 2030 

Seventy million American homes and businesses burn natural gas, oil, or propane on-site to heat their space and water, generating 560 million tons of carbon dioxide each year—one-tenth of total U.S. emissions. All homes and buildings must be decarbonized by 2050 to reach carbon neutrality. The first phase of reaching this goal is ensuring that new buildings constructed this decade are not designed to burn fossil fuels. There are immediate emissions savings because all-electric buildings are more efficient, and their emissions will continue to decrease as the electricity supply gets cleaner. There are also significant health impacts associated with burning fossil fuels indoors and the risk of explosions, meaning that all electric buildings are safer and healthier for people. 

As of August 2021, 3 of the top 100 largest U.S. cities have enacted local policies preventing fossil fuel use in new buildings. 

100% carbon free electricity by 2035 

Electrifying buildings and transportation will not lead to carbon neutrality until the electricity supply is carbon neutral. Currently renewables, large-scale hydro, and nuclear energy comprise 38% of electricity generation in the U.S. The other 62% is from fossil fuels that will need to be replaced in the coming decade to meet our climate goals. We see a tremendous opportunity for the coming energy transition to create a new energy system that builds wealth in local communities. 

Based on 2019 data, currently 4 of the top 100 largest U.S. cities are in states where carbon-free electricity is over 65%.