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Greenhouse Gas Emissions

Greenhouse gas emissions (GHGs) from energy use, waste, and transportation trap heat and drive climate change impacts like rising temperatures, sea levels, and extreme weather. Cambridge is committed to significantly reducing GHGs by 2050 to help avoid these severe impacts. 

City buildings lit up at night

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. 

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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

2023 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 2023, city-owned buildings produced 67% of all emissions from municipal activities.

Municipal GHG Emissions

2023 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.

Image of buildings on a tree-lined street on front cover of City plan document

How Does Cambridge Track Emissions?

Cambridge has reduced its GHG emissions from Municipal operations by 38% between 2008 and 2022 by decreasing energy use, switching to cleaner fuels, and reducing waste.

Learn more about Cambridge's GHG Emissions Inventories