Living Our Values

GHG Emissions from Previous Years

We have not adjusted EDF’s Past Travel or Office Energy Emissions using the emissions factors for FY 2022.

Defining Full-Time Employees

We calculated FTEs as an employee’s scheduled hours divided by the number of hours for a full-time workweek. To account for new hires and departures in FY 2022, we calculated FTEs on a monthly basis and used the annual average. Reports from prior years included regular and temporary contingent staff members, so FTE numbers (and therefore emissions intensity per FTE) are not fully comparable across years.

Calculating Emissions from Travel

EDF’s Travel Policy requires employees to book travel through a corporate travel provider, which is the source of much of our travel activity data. This report does not include any business-related travel that EDF staff may have arranged outside a preferred travel provider.

Commuting emissions were calculated using data from a survey of EDF employees about their pre-pandemic commuting habits.

Calculating Emissions from Air Travel

Seat numbers were based on the U.K.’s Department for Environment, Food and Rural Affairs (DEFRA) 2022 methodology paper for emissions factors.

Aviation has additional climate impacts from the radiative forcing of contrails. We purchase additional carbon credits to account for this effect. We will continue to monitor this area of research.

Calculating Emissions from Rail Travel

We collected rail travel data from EDF’s corporate travel provider, and we used an emissions factor of 0.058 kgCO₂/mile for the U.S. Northeast Corridor and 0.150 kgCO₂/mile for all other rail routes, as defined by the U.S. EPA.

Calculating Emissions from Vehicle Travel

For miles driven in personal vehicles for business purposes, we used data from EDF’s expense reimbursement records. In the absence of actual data on miles driven in rental vehicles, we assumed that rental cars were driven an average of 36.92 miles per day, based on the U.S. Department of Transportation Federal Highway Administration estimate that the average American’s annual mileage is 13,476 per year. We used emissions factors from the U.S. EPA.

Calculating Emissions from Hotel Stays

We collected data from EDF’s corporate travel provider and from EDF trustee hotel stays related to attending board meetings and events. We used country- and (where available) city-specific emissions factors from the Cornell Hotel Sustainability Benchmarking Index.

The global food system produces significant GHG emissions, but we have not included such emissions in our inventories thus far. We are investigating the best way to account for food-related emissions from hotel stays, conferences and events.

Calculating Emissions from Employee Commutes

We conducted an anonymous staff survey in April 2020 to gather data about pre-pandemic commuting, including but not limited to modes of transportation, distance traveled and commuting frequency. The survey received a 62% response rate, with proportional representation of offices and programs. We assumed the survey responses were representative of all staff, and that employees commuted more in FY 2022 than in FY 2020. We used emissions factors defined by the U.S. EPA.

Calculating Emissions from Office Energy Use

We collected data from property managers and energy providers, and we used emissions factors from the following sources:

• For Austin, Boston (electricity), Boulder, New York, Raleigh, San Francisco (electricity) and Washington, DC we used conversion factors from the U.S. EPA’s eGRID output rates.
• For Beijing we used emissions factors from the GHG protocol.
• For natural gas usage in New York and San Francisco, we used emissions factors from the IPCC.
• For Boston (district steam), we used emissions factors from the U.S. EPA.
• For Jakarta, we used conversion factors from Enerdata.
• For La Paz, we used emissions factors from Registro Nacional de Emisiones.
• For London, we used emissions factors from DEFRA.

Office energy emissions include CO₂, CH₄ and N₂O. The emissions of non-CO₂ gases from direct electricity generation are minimal. However, CH4 leaks in the natural gas supply chain have additional climate impacts. To calculate fugitive CH₄ emissions from the electricity supply chain, we used state-specific upstream leak rates of delivered gas. For international offices, we assumed a leak rate of 2.9% We also included state-specific heat content of consumed natural gas (U.S. Energy Information Administration) and the fraction of electricity generation by fuel (U.S. EPA eGRID). We assumed a power plant efficiency of 7,732 BTU/kwh (U.S. Energy Information Administration). To calculate fugitive CH₄ emissions from the natural gas supply chain, we assumed a leak rate of 2.9% and used state-specific heat content of consumed natural gas (U.S. Energy Information Administration).

Two offices had missing or anomalous energy data.

• New York City: Building management in the NY office does not provide natural gas usage data per tenant or floor. We assumed our use was a percentage of the building’s total use, based on square footage.
• Raleigh: This office is not sub-metered. We estimated our energy use as a percentage of the building’s total use, based on square footage.

Calculating Emissions from Paper Use

EDF’s Development Department tracks the weight of membership mailings and contracted projects. EDF offices in the U.S. track paper use with PaperCut print management software. We used purchase records to estimate paper usage in the London office. Due to a lack of data on paper use, this report does not include emissions from office paper used in Beijing, Jakarta or La Paz. This is a data gap we will work to fill in future reports. U.S. offices use TreeZero paper. According to TreeZero, the production and distribution of their sugarcane waste-based paper generates 1 tCO₂ per ton of paper. The price of TreeZero paper includes the cost of carbon credit purchases, but we included the emissions in this inventory and purchased carbon credits for those emissions.

For external printing and membership mailings, we used emissions factors from the Environmental Paper Network, Paper Calculator Version 4.0, except for CH₄, where we used a GWP-20 of 84, not the Paper Calculator’s default of 102.9 For more information visit www.papercalculator.org. The conversions were 4.04 tCO₂e (GWP-20) / 2.62 tCO₂e (GWP-100) per ton of paper with 100% recycled content and 6.18 tCO₂e (GWP-20) / 4.79 tCO₂e (GWP-100) per ton of paper with 30% recycled content. This calculation does not include emissions from shipping the materials from printers to recipients. We hope to calculate these emissions in future inventories.

Emissions of Other Pollutants

GHG emissions from travel, office energy, and paper included CO₂, CH₄, and N₂O. The emissions factors for paper and office energy also included other pollutants that have a range of deleterious effects on human health and the environment. Most of these pollutants have atmospheric lifetimes on the order of hours to weeks, so including them in calculations of our overall climate impacts over decades-long time horizons is inappropriate. We report them separately here. We are considering how to mitigate the impact of such emissions in the future.

Other Pollutant Emissions from Office Energy Use

• • Other Pollutant Emissions from Office Energy Use
  • Mg (t)
  • tCO₂e (GWP-20)
  • tCO₂e (GWP-100)
• • Nitrogen oxides (NO_x)
  • 0.13
  • 16
  • -1.5
• • Sulfur dioxide (SO₂)
  • 0.05
  • -12
  • -1.8