Greenhouse Gas Emissions
Greenhouse gas emissions (GHGs) are produced when we use energy in our homes and offices, dispose of waste or sewage, and use vehicles. GHGs trap heat in the atmosphere, leading to lasting disruptions in our climate, such as higher temperatures, sea level rise, and more frequent extreme weather events that can cause flooding. Cambridge, along with many other cities, organizations, and businesses, both nationally and internationally, has committed to significantly reduce GHG emissions by 2050 to avoid severe impacts from climate change.
Community GHG Emissions
Our Goals
Cambridge has established a goal to have net-zero GHG emissions community-wide by 2050.
In 2022, the City conducted a greenhouse gas (GHG) emissions inventory with data from 2019. Cambridge has committed to the Global Covenant of Mayors (GCoM), a global network of cities that have committed to reducing emissions, which requires that we update the inventory every 3 to 5 years.
UNIT | Greenhouse gases (GHGs) have a natural heat trapping capacity which varies by gas. Humans produce more carbon dioxide (CO2) than any other GHG. We count emissions of GHGs based on how each GHG’s heat trapping capacity compares to CO2s. This is called the "CO2 equivalent" (CO2e). We measure GHGs in metric tons of CO2e (MTCO2e). | MTCO2eMetric Tons Carbon Dioxide Equivalent |
Greenhouse gases (GHGs) have a natural heat trapping capacity which varies by gas. Humans produce more carbon dioxide (CO2) than any other GHG. We count emissions of GHGs based on how each GHG’s heat trapping capacity compares to CO2s. This is called the "CO2 equivalent" (CO2e). We measure GHGs in metric tons of CO2e (MTCO2e). | MTCO2eMetric Tons Carbon Dioxide Equivalent |
Community GHG Emissions
2019 Community Emissions by Sector
Buildings are the largest sector of community GHG emissions in Cambridge, with commercial and institutional buildings accounting for just over a third (37%) of all community emissions. Residential buildings (20%) and then energy industries (13%), which are the generation facilities that provide electricity and heat for the commercial and institutional properties, follow this. On-road transportation, which includes all the cars, trucks, and buses that travel on our streets, represents only 9% of the City’s total GHG emissions. The Waste sector comprises a total of 7% of our total emissions.
Municipal GHG Emissions
Trends over time
In 2022, the City reduced greenhouse gas emissions (ghg) from municipal operations 38% below 2008 levels. The chart also depicts the significant impact of the planned procurement of 100% renewable electricity supply from a new renewable system with a commercial operation date on or about Dec. 2025.
Cambridge has established a Municipal GHG reduction goal of 30% below 2008 levels by 2020, with a stretch goal of 35%, and Net-Zero by 2050.
How Does Cambridge Track Municipal Emissions?
Cambridge has reduced its GHG emissions by 38% between 2008 and 2022 by decreasing energy use, switching to cleaner fuels, and reducing waste.
Municipal GHG Emissions
2022 Emissions by Sector
We look at GHG emissions by sector to determine the amount of emissions being produced by various city activities. Buildings in Cambridge both consume the most energy and produce the greatest volume of emissions at the municipal and community-wide scale. In 2022, city-owned buildings produced 69% of all emissions from municipal activities.
Municipal GHG Emissions
2022 Emissions By Fuel Type
Electricity and natural gas are the two primary fuel types that produce greenhouse gas (GHG) emissions from our municipal operations. This is not surprising given that the buildings sector is our number one emitter and that is largely where energy is being consumed.
This pie chart also shows us where there are opportunities to improve. The City has learned a lot about how to be more efficient in our buildings and to integrate renewable energy into our facilities - demonstrated by the 33% reduction that has already been achieved.
Did You Know?
Cambridge's 2022 GHG emissions from municipal operations are equivalent to the GHG emissions from 3,802 passenger vehicles driving for one year.
How You Can Help
Reduce Your Carbon Footprint
Throughout our daily lives, we all take actions that produce GHGs. Here are some actions you can take to reduce your contribution to the community's emissions:
- Reduce your energy use at home or work. Buildings represent nearly two-thirds of community GHG emissions.
- Switch to renewable energy. Clean energy sources produce fewer GHGs than fossil fuels.
- Reduce your waste by recycling and composting. Solid waste and incineration accounts for 6.4% of community GHG emissions.
- Prioritize low-carbon transportation. Cambridge residents have many options to get around without a vehicle.
