Environment

Environmental data including emissions, energy, water and waste

Greenhouse Gas Emissions

Direct (Scope 1) emissions
2023metric tons CO2e 2022metric tons CO2e 2021metric tons CO2e 2020metric tons CO2e
Direct (Scope 1) emissions 36,590,472 30,400,715 21,375,325* 15,485,363
Mainline aircraft direct emissions 36,454,532 30,263,431 21,253,385 15,392,492
Conventional jet fuel 36,454,016 30,263,216 21,253,316* 15,392,491*
Sustainable aviation fuel – CH4 and N2O 517 215 68* 45*
Mainline vehicles (diesel, gasoline, CNG, LPG)2 52,976 47,447 38,242 24,766
Facilities (natural gas combustion, engine test cells) 82,964 89,837 81,997 70,797
Dry ice from catering 0 0 1,720 2,015

Biogenic emissions – outside of scopes
2023metric tons CO2e 2022metric tons CO2e 2021metric tons CO2e 2020metric tons CO2e
Biogenic emissions – outside of scopes 67,395 26,806 5,745* 5,976*
Mainline aircraft emissions – CO2 from sustainable aviation fuel 67,395 26,806 5,745* 5,976*

Indirect (Scope 2) emissions
2023metric tons CO2e 2022metric tons CO2e 2021metric tons CO2e 2020metric tons CO2e
Indirect (Scope 2) emissions 144,019 149,252 160,794 175,087
Electricity consumption (location-based) 160,340 166,757 183,311 196,066
Electricity consumption (market-based) 143,991 149,251 160,794 175,087
Steam consumption 28 0 0 0

Other Indirect (Scope 3) emissions
2023metric tons CO2e 2022metric tons CO2e 2021metric tons CO2e 2020metric tons CO2e
Other Indirect (Scope 3) emissions 12,671,510 13,343,676 11,926,943* 8,982,191*
Category 3 – Mainline aircraft fuel production 7,391,936 7,250,196 5,106,045* 4,701,874*
Conventional jet fuel 7,377,946 7,246,478 5,104,506* 3,752,824*
Sustainable aviation fuel 13,990 3,718 1,538* 1,491*
Category 4 – Regional aircraft direct emissions and fuel production 4,873,562 5,587,322 1,259,152* 94,7558*
Regional aircraft and bus-operated flights flown under capacity purchase agreement – direct emissions 4,048,183 4,504,664 5,294,725 4,053,434
Regional vehicles (diesel, gasoline, CNG, LPG)2 12,799 14,533 15,481 13,658
Regional aircraft flown under capacity purchase agreement – fuel production 789,189 1,030,688 1,202,863* 908,708*
Regional aircraft flown on an at-risk basis – fuel production 23,391 37,437 56,289* 38,849*
Category 7 – Employee commuting 125,795 111,108 52,278 80,980
Category 14 – Regional aircraft flown on an at-risk basis 122,425 163,902 243,553 0
Category 15 – Ownership stake in Azul Brazilian Airlines 156,432 229,912 199,099 132,220
Category 15 – United Airlines Ventures investments3 1,361 1,236 162 24

Gross emissions
2023metric tons CO2e 2022metric tons CO2e 2021metric tons CO2e 2020metric tons CO2e
Gross GHG emissions 49,406,001 43,893,642 33,463,063* 24,647,396*
Carbon offsets 0 0 0 0
Net GHG emissions 49,406,001 43,893,642 33,463,063* 24,647,396*

Efficiency numbers
2023 2022 2021 2020
Revenue passenger-miles (RPM), in millions – mainline and regional 244,585 206,791 128,979 73,883
Metric tons CO2e per million RTKs – mainline and regional4 1,056.9 1,097.7 1,106.6** 1,337.7*
Revenue tonnes-kilometers (RTK), in millions – mainline and regional 46,361 39,526 25,212 15,934
Available seat-miles (ASMs), in millions – mainline and regional 291,566 247,858 178,684 122,804
Metric tons CO2e per million ASMs – mainline and regional 168.9 176.2 186.2** 199.6*

Energy consumption

2023 2022 2021 2020
Conventional jet fuel – Mainline aircraft, in millions of gallons 3,779 3,139 2,205 1,600
Sustainable aviation fuel – Mainline aircraft, in millions of gallons 7 3 1 1
Lifecycle reduction from SAF 77.9% 86.9% 83.4% 79.3%
Emissions reductions from SAF (metric tons CO2e) 11,308 3,419 987 8,517
Conventional jet fuel – Regional aircraft, in millions of gallons 418 466 523 404
Electricity (MWh) 434,790 435,259 447,714 477,751
Natural gas (MM BTUs) 1,481,604 1,628,722 1,494,698 1,264,964

Local air quality

Nitrogen Oxide emissions
2023tons 2022tons 2021tons 2020tons
NOx emissions from mainline aircraft 10,356 14,948 10,813 7,660
NOx emissions (old) 11,554 16,144 11,626 8,565
Mainline aircraft (jet fuel) 10,356 14,948 10,813 7,660
Vehicles (diesel, gasoline, CNG, LPG)2 1,197 1,196 813 905
Facilities (Natural gas combustion, engine test cells) 156 153 121 130

Sulfur Dioxide emissions
2023tons 2022tons 2021tons 2020tons
SO2 emissions from mainline aircraft 1,250 1,413 1,022 730
SO2 emissions (old) 1,251 1,414 1,022 731
Mainline aircraft (jet fuel) 1,250 1,413 1,022 730
Vehicles (diesel, gasoline, CNG, LPG) 0 0 0 0
Facilities (Natural gas combustion, engine test cells) 1 1 1 1

Carbon Monoxide emissions
2023tons 2022tons 2021tons 2020tons
CO emissions from mainline aircraft 9,027 7,805 5,503 3,743
CO emissions (old) 16,089 16,759 10,507 9,207
Mainline aircraft (jet fuel) 9,027 7,805 5,503 3,743
Vehicles (diesel, gasoline, CNG, LPG)2 6,977 8,864 4,921 5,388
Facilities (Natural gas combustion, engine test cells) 85 91 83 76

Waste management
2023metric tons 2022metric tons 2021metric tons 2020metric tons
Waste–total 59,025 25,176 31,407 26,667
Hazardous and non-hazardous waste generation 19,303 22,399 24,253 15,602
Catering–Municipal waste 37,014 2,776 10,367 11,066
Hazardous Moved to new category Moved to new category Moved to new category Moved to new category
Non-hazardous/other waste Moved to new category Moved to new category Moved to new category Moved to new category
Recycling–total 9,209 6,112 5,818 4,468
Non-catering–recycled 5,047 5,255 4,446 3,302
Catering–recycled 4,158 857 1,372 1,166

Water consumption

2023millions of gallons 2022millions of gallons 2021millions of gallons 2020millions of gallons
Billed water consumption5 429 329 661 484

The data presented herein reflecting United’s 2023 GHG emissions footprint has been internally validated by United Airlines Internal Audit Department and externally verified by our third-party verification partner ERM CVS. United obtains this third-party verification of our Selected Information on an annual basis. ERM Certification and Verification Services (ERM CVS, a wholly owned subsidiary of the ERM Group, a global market leader in sustainability services) conducts our emissions verification and provides an ISO 14064-3 limited assurance on our GHG emissions for reporting.

Download our GHG Emissions Verification Report

Footnotes

  1. United accounts emissions reductions associated with the use and combustion of sustainable aviation fuel (SAF) to be a Scope 1 reduction, as it is in-sector and a sustainable alternative to the conventional jet fuel usage that is accounted in the gross emissions of this Scope. This is an interpretation of the GHG Protocol, until such time that an accepted GHG accounting methodology is developed to reflect in-sector reductions associated to biogenic products.
  2. United changed to a more straightforward methodology to determine GHG emissions from GSE starting with 2018 reporting, but has not restated prior years; this change also re-allocated GHG emissions between Mainline and Regional GSE
  3. United Airlines Ventures investments in Alder Fuels, Archer Aviation, Boom, Clear, Fulcrum BioEnergy, Heart Aerospace, and ZeroAvia (some of which may not have developed GHG inventories yet)
  4. Intensity metric is used to track United's progress against our SBTi near term target it includes Scope 1, Scope 2, and Scope 3 category 3 and 4 emissions
  5. Does not account for all United locations or locations shared with other companies (e.g., airport terminals) and as a result may change considerably from year to year

* This data point has been added or updated to reflect the change in our GHG accounting methodology made in 2023 as referenced in our 2023 Corporate Responsibility Report and accurately tracking against our SBTi validated mid-term goal.

** This calculation has been updated since the publishing of United’s Form 10K to include Scope 3 Categories 3 & 4 for comparability with the 2023 emissions disclosures which include these emission categories. Inclusion of these Scope 3 emission categories reflects a change in our GHG accounting methodology as referenced in our Corporate Responsibility Report and accurately tracking against our SBTI-validated mid-term goal.

Totals may not add up due to rounding.