Additional GHG Accounting

Preliminary and emerging scope 3 greenhouse gas emissions assessments are tracked in a separate inventory from the main Cornell GHG baseline inventory used to measure progress towards carbon neutrality by 2035.

What does Cornell measure as part of its baseline inventory, and what additional Scope 3 areas have been completed in the additional inventory? Click on this diagram to enlarge and learn more.

What is "Additional Accounting"?

Cornell maintains a baseline GHG inventory and publishes additional GHG accounting here.

The baseline greenhouse gas inventory includes accounting areas required by our public commitment to reach carbon neutrality as part of the Second Nature Carbon Commitment. Read more about our baseline inventory methodology here.

New areas of Scope 3 accounting are measured and reported separately in the additional inventory.  The additional GHG inventory allows members of the camps community to contribute to a wider view of Cornell's organizational climate impact, without changing the original "goalposts" of the public carbon commitment. 

These additional areas of accounting also allows faculty and students to contribute to emerging greenhouse gas accounting science using Cornell facilities as a living laboratory to inform operational best practices and test solutions to scale for greater impact. Some additional inventories were completed once, others may be updated annually.  Additional inventories are the responsibility of the interested party to assess and keep up to date.

Additional Inventory Assessments Available

Baseline and Additional Comparison

Most additional inventories use exploratory methodologies and calculations, and/or have significant amounts of uncertainty, therefore, some inventories present both 'high' and 'low' emissions scenarios. 

Note: These inventories use various fiscal years' data depending on when the inventory was completed. 


Inventory first performed in FY2020 using the SIMAP Calculator by the Campus Sustainability Office.

This accounting area measures the carbon footprint from Cornell's disposal of landfill waste and wastewater. 

FY2020 Assessment

Cornell's landfill waste is processed at a site with methane (CH4) recovery and electric generation, so the carbon impact of institutional waste is lower than if the waste went to a "traditional" landfill.  This area can be reduced by producing less landfill waste on campus, and increasing recycling & composting.  Some wastewater is sent to a local anaerobic digester, which also reclaims wastewater and ensures it is used for energy production. 

This preliminary assessment suggests waste emissions are de minimus, meaning they comprise less than 1% of Cornell's total GHG footprint.  

Purchased Goods 

Inventory first performed in FY2019 using a new methodology created by Professor Natalie Mahowald, Earth and Atmospheric Sciences, the Campus Sustainability Office, and a student research team in partnership with Cornell Atkinson Center for Sustainability and The Sustainability Consortium.

This accounting area measures the greenhouse gas impact of Cornell's purchased goods across a wide variety of categories such as medical equipment, furniture, food, electronics, laboratory supplies, and building construction materials.

FY2019 Assessment

Dr. Natalie Mahowald, professor in Earth and Atmospheric Sciences and lead scientist for The Intergovernmental Panel on Climate Change (IPCC) and Campus Sustainability Director Sarah Zemanick led a team of students EAS4900 during Spring 2019 to create the first comprehensive Scope 3 inventory of Cornell's purchased goods, using data available from procurement services at the University.

This preliminary assessment made initial attempt to clean and classify procurement data into logical groupings by which carbon emissions impacts could be measured. The course produced a supporting documents detailing their methodology, data classification, and results.

As of 2021, Professor Mahowald and University partners are working to use this preliminary assessment to develop a rigorous methodology that could be used by higher education partners across North America, in partnership with the UNH SIMAP team.

Upstream Fuel Activities

Inventory completed in 2016 by Professor Bob Howarth, Ecology and Evolutionary Biology

This accounting area is studied emissions from methane during the process of natural gas extraction and delivery.  Cornell uses natural gas as a fuel source to heat and power the campus as part of our District Energy Combined Heat & Power.

FY2016 Assessment

Cornell University and Tompkins County include a preliminary assessment of the upstream impacts of natural gas as part of Cornell's 2016 Options for a Carbon Neutral Campus Report - a report advancing the Climate Action Plan - and the Tompkins County greenhouse gas inventory completed the same year. 

Recognizing that methane is a powerful greenhouse gas, these preliminary assessments showed the impact of purchasing natural gas and related upstream methane leakage that occurs during the extraction of natural gas, and from pipeline distribution.  Upstream and downstream greenhouse gas emissions accounting protocols are emerging methodologies, and as such, will continue to fluctuate as new science and technologies evolve.

2020 Update

Since the accounting published in the Options Report, Cornell researchers and others have revised the approximate leakage rate of methane, which alters the corresponding emissions measured as part of upstream fuel activities.

In 2020, the Sustainable Cornell Council began a working group to further explore this accounting area.  The group discussed different options for Cornell to assess the methane emissions associated with the production and distribution of natural gas used at the Cornell Central Energy Plant, guided by the Intergovernmental Panel on Climate Change (IPCC) Assessments. The group’s conclusions and updated estimates will be shared when finalized.

Forest Carbon Sinks

Information coming soon.