Fuel efficiency and emissions reduction

Improvements in fuel efficiency

Improving fuel efficiency is critical to our ability to manage our carbon footprint. Here are the actions we take to improve our fuel efficiency.

In the air

Since 1990, we've improved our fuel efficiency by more than 45 percent. United has made significant investments in a modern, fuel-efficient fleet while implementing operational and procedural changes to drive fuel conservation.

Weight reductions

We constantly review the amenities of our aircraft for lighter-weight alternatives, as lighter aircraft consume less fuel and produce fewer emissions. Learn more

Single-engine taxiing

Shutting down one engine and taxiing on the other saves five million gallons per year, or the equivalent of removing 9,000 cars from the road.

Continuous descent approaches

By avoiding applying thrust at low altitudes, aircraft can save fuel—while also reducing noise impacts to cities.

Towing aircraft

Rather than taxiing aircraft between flights, United’s fleet of 69 SuperTugs at 10 airports saves eight million gallons each year by moving nearly 500 aircraft every day between the gates and hangars.

Engine washes

We routinely wash our aircraft engines to reduce drag and emissions.

Auxiliary power unit savings

Where possible, we provide aircraft parked at the gate with air conditioning and electric power via alternative, emissions-reducing methods rather than using the aircraft’s auxiliary power unit.

On the ground and at our facilities

On the ground

Over 4,000 of our ground service equipment (GSE) around the world are electric or use alternative fuels, including high adoption at airports such as Los Angeles (70 percent), Houston (70 percent) and San Francisco (65 percent). United also encourages employee ridesharing, and provides commuter benefits and electric vehicle charging at select locations.

At our facilities

United has LEED certified buildings in Chicago, Houston and San Francisco. One of the largest green roofs in Chicago is on our United Cargo building at O’Hare. Also, we’re conducting an energy efficiency audit on our top 10 energy using facilities in our network, which make up 85 percent of our non-fuel energy use.


Chart, aviation’s impact on the environment.  The entire aviation industry produces approximately two percent of human-induced carbon dioxide emissions. Other industries account for 98 percent of human-induced carbon dioxide emissions. Major contributors include: electricity and heat production, 25 percent; agriculture, forestry and other land use, 24 percent; industry, 21 percent; non air transportation, 12 percent; other energy, 10 percent; buildings, 6 percent.

Aviation’s impact on the environment

Aviation stimulates the economy, trade and tourism, generates business opportunities and enhances quality of life in both developed and developing regions. However, aviation does produce approximately two percent of human-caused CO2 emissions.

We support a global approach to addressing greenhouse gas emissions. Together with other airlines, engine and airframe manufacturers, fuel suppliers, airports and governments, we’re working towards a collective industry goal of 1.5 percent average annual fuel efficiency improvement through 2020, carbon neutral growth beginning in 2020 and a 50 percent reduction in airline CO2 emissions by 2050.

United is involved with the Carbon Disclosure Project (CDP), becoming the first U.S. airline to participate. For additional information on our carbon footprint and climate change strategy, view our latest CDP questionnaire response.

You can also view our entire emissions footprint on our Corporate Responsibility Report. Read more

There are three types of emissions we have, explained below this image. The total emissions for Scope 1, labeled in blue, are 31,447,052 metric tons of carbon dioxide equivalent. The total emissions for Scope 2, labeled in yellow, are 291,543 metric tons of carbon dioxide equivalent. The total emissions for Scope 3, labeled in teal, are 6,268,793 metric tons of carbon dioxide equivalent. There are three types of emissions we have, explained below this image. The total emissions for Scope 1, labeled in blue, are 31,447,052 metric tons of carbon dioxide equivalent. The total emissions for Scope 2, labeled in yellow, are 291,543 metric tons of carbon dioxide equivalent. The total emissions for Scope 3, labeled in teal, are 6,268,793 metric tons of carbon dioxide equivalent. There are three types of emissions we have, explained below this image. The total emissions for Scope 1, labeled in blue, are 31,447,052 metric tons of carbon dioxide equivalent. The total emissions for Scope 2, labeled in yellow, are 291,543 metric tons of carbon dioxide equivalent. The total emissions for Scope 3, labeled in teal, are 6,268,793 metric tons of carbon dioxide equivalent.
Blue - Scope 1

Emissions from sources that are owned and/or controlled by United. This includes:

Jet fuel for United flights -31,282,902*

Biofuel - 10,237

Vehicles - 78,196

Facilities - 72,486

Dry ice from catering - 3,231

*in metric tons CO2e

Yellow - Scope 2

Emissions from the consumption of purchased electricity or other energy sources. This includes:

Electricity consumption - 291,543

Green - Scope 3

Emissions from sources not directly owned and/or controlled by United. This includes:

Regional jet fuel - 6,157,267

Ownership stakes in other companies - 109,678

Vehicles - 1,847

United Global Performance Commitment

Our industry-leading program for select corporate travel partners represents our continued commitment to operational performance excellence throughout the entire travel process. In 2017, United added an environmental commitment that we’ll have a lower gross carbon footprint than American and Delta.

Learn more

United Eco-Skies CarbonChoice carbon offset program

Through the Eco-Skies® CarbonChoice program, United offers customers and businesses the opportunity to purchase carbon offsets to reduce the carbon footprint associated with their air travel and cargo shipments.

Learn more

Emissions and other data

Every year, we report on our carbon emissions, local air quality, waste management, water and energy consumption and more. See the table below for our latest data.

Carbon emissions

Carbon emissions - Direct (Scope 1) emissions
 
2017 in metric tons CO2e
2016 in metric tons CO2e
2015 in metric tons CO2e
2014 in metric tons CO2e
Direct (Scope 1) emissions 32,425,313 31,447,052 31,446,166 31,132,366
Aircraft (jet fuel) 32,269,841 31,282,902 31,279,288 30,966,621
Aircraft (biofuel) 3,822 10,237 0 0
Vehicles (diesel, gasoline, CNG, LPG) 69,084 78,196 78,315 75,361
Facilities (natural gas combustion, engine test cells) 79,169 72,486 88,563 90,384
Dry ice from catering 3,397 3,231 Not reported Not reported
Intensity ratio (Scope 1+2 metric tons CO2e / 1000 RTMs)1 1.317 1.348 1.372 1.423

Carbon emissions - Direct (Scope 1) emissions

  • 2017 in metric tons CO2e

    32,425,313
  • 2016 in metric tons CO2e

    31,447,052
  • 2015 in metric tons CO2e

    31,446,166
  • 2014 in metric tons CO2e

    31,132,366

  • 2017 in metric tons CO2e

    32,269,841
  • 2016 in metric tons CO2e

    31,282,902
  • 2015 in metric tons CO2e

    31,279,288
  • 2014 in metric tons CO2e

    30,966,621

  • 2017 in metric tons CO2e

    3,822
  • 2016 in metric tons CO2e

    10,237
  • 2015 in metric tons CO2e

    0
  • 2014 in metric tons CO2e

    0

  • 2017 in metric tons CO2e

    69,084
  • 2016 in metric tons CO2e

    78,196
  • 2015 in metric tons CO2e

    78,315
  • 2014 in metric tons CO2e

    75,361

  • 2017 in metric tons CO2e

    79,169
  • 2016 in metric tons CO2e

    72,486
  • 2015 in metric tons CO2e

    88,563
  • 2014 in metric tons CO2e

    90,384

  • 2017 in metric tons CO2e

    3,397
  • 2016 in metric tons CO2e

    3,231
  • 2015 in metric tons CO2e

    Not reported
  • 2014 in metric tons CO2e

    Not reported

  • 2017 in metric tons CO2e

    1.317
  • 2016 in metric tons CO2e

    1.348
  • 2015 in metric tons CO2e

    1.372
  • 2014 in metric tons CO2e

    1.423
Carbon emissions - Indirect (Scope 2) emissions
 
2017 in metric tons CO2e
2016 in metric tons CO2e
2015 in metric tons CO2e
2014 in metric tons CO2e
Indirect (Scope 2) emissions 235,794 291,543 283,499 416,062
Electricity consumption 235,794 291,543 283,499 416,062

Carbon emissions - Indirect (Scope 2) emissions

Indirect (Scope 2) emissions

  • 2017 in metric tons CO2e

    235,794
  • 2016 in metric tons CO2e

    291,543
  • 2015 in metric tons CO2e

    283,499
  • 2014 in metric tons CO2e

    416,062

Electricity consumption

  • 2017 in metric tons CO2e

    235,794
  • 2016 in metric tons CO2e

    291,543
  • 2015 in metric tons CO2e

    283,499
  • 2014 in metric tons CO2e

    416,062
Carbon emissions - Other Indirect (Scope 3) emissions
 
2017 in metric tons CO2e
2016 in metric tons CO2e
2015 in metric tons CO2e
2014 in metric tons CO2e
Other Indirect (Scope 3) emissions 6,078,739 6,268,793 6,474,314 7,022,328
Regional jet fuel 5,977,955 6,157,267 6,472,504 7,020,223
Vehicles (diesel, gasoline, CNG, LPG) 1,789 1,847 1,809 2,105
Ownership stakes in other companies 98,996 109,678 Not reported Not applicable

Carbon emissions - Other Indirect (Scope 3) emissions

  • 2017 in metric tons CO2e

    6,078,739
  • 2016 in metric tons CO2e

    6,268,793
  • 2015 in metric tons CO2e

    6,474,314
  • 2014 in metric tons CO2e

    7,022,328

  • 2017 in metric tons CO2e

    5,977,955
  • 2016 in metric tons CO2e

    6,157,267
  • 2015 in metric tons CO2e

    6,472,504
  • 2014 in metric tons CO2e

    7,020,223

  • 2017 in metric tons CO2e

    1,789
  • 2016 in metric tons CO2e

    1,847
  • 2015 in metric tons CO2e

    1,809
  • 2014 in metric tons CO2e

    2,105

  • 2017 in metric tons CO2e

    98,996
  • 2016 in metric tons CO2e

    109,678
  • 2015 in metric tons CO2e

    Not reported
  • 2014 in metric tons CO2e

    Not applicable

Local air quality

Local air quality - NOx emissions
 
2017 in tons NOx
2016 in tons NOx
2015 in tons NOx
2014 in tons NOx
NOx emissions 15,074 17,881 13,139 13,027
Mainline aircraft (jet fuel) 14,143 16,823 11,988 11,864
Vehicles (diesel, gasoline, CNG, LPG) 814 946 1,022 1,032
Facilities (Natural gas combustion, engine test cells) 117 111 129 131

Local air quality - NOx emissions

  • 2017 in tons NOx

    15,074
  • 2016 in tons NOx

    17,881
  • 2015 in tons NOx

    13,139
  • 2014 in tons NOx

    13,027

  • 2017 in tons NOx

    14,143
  • 2016 in tons NOx

    16,823
  • 2015 in tons NOx

    11,988
  • 2014 in tons NOx

    11,864

  • 2017 in tons NOx

    814
  • 2016 in tons NOx

    946
  • 2015 in tons NOx

    1,022
  • 2014 in tons NOx

    1,032

  • 2017 in tons NOx

    117
  • 2016 in tons NOx

    111
  • 2015 in tons NOx

    129
  • 2014 in tons NOx

    131
Local air quality - SO2 emissions
 
2017 in tons SO2
2016 in tons SO2
2015 in tons SO2
2014 in tons SO2
SO2 emissions 1,367 1,598 1,173 1,171
Mainline aircraft (jet fuel) 1,366 1,597 1,172 1,170
Facilities (Natural gas combustion, engine test cells) 1 1 1 1

Local air quality - SO2 emissions

  • 2017 in tons SO2

    1,367
  • 2016 in tons SO2

    1,598
  • 2015 in tons SO2

    1,173
  • 2014 in tons SO2

    1,171

  • 2017 in tons SO2

    1,366
  • 2016 in tons SO2

    1,597
  • 2015 in tons SO2

    1,172
  • 2014 in tons SO2

    1,170

  • 2017 in tons SO2

    1
  • 2016 in tons SO2

    1
  • 2015 in tons SO2

    1
  • 2014 in tons SO2

    1
Local air quality - CO emissions
 
2017 in tons CO
2016 in tons CO
2015 in tons CO
2014 in tons CO
CO emissions 9,414 11,034 9,164
9,231
Mainline aircraft (jet fuel) 7,478 9,058 6,370 6,324
Vehicles (diesel, gasoline, CNG, LPG) 1,875 1,918 2,724 2,836
Facilities (Natural gas combustion, engine test cells) 60 58 70 71

Local air quality - CO emissions

  • 2017 in tons CO

    9,414
  • 2016 in tons CO

    11,034
  • 2015 in tons CO

    9,164
  • 2014 in tons CO

    9,231

  • 2017 in tons CO

    7,478
  • 2016 in tons CO

    9,058
  • 2015 in tons CO

    6,370
  • 2014 in tons CO

    6,324

  • 2017 in tons CO

    1,875
  • 2016 in tons CO

    1,918
  • 2015 in tons CO

    2,724
  • 2014 in tons CO

    2,836

  • 2017 in tons CO

    60
  • 2016 in tons CO

    58
  • 2015 in tons CO

    70
  • 2014 in tons CO

    71

Waste management

Waste - total
 
2017 in metric tons
2016 in metric tons
2015 in metric tons
2014 in metric tons
Waste — total 61,232 41,786 43,756
49,948
Hazardous and non-hazardous waste generation 34,120 16,729 -
-
Catering — Municipal waste 27,112 25,057 - -
Hazardous Moved to new category Moved to new category 2,565 555
Non-hazardous/other waste Moved to new category Moved to new category 41,191
49,393
Recycling — total 9,015 7,302 14,942
9,329
Non-Catering — recycled 5,326 4,093 12,840 6,454
Catering — recycled 3,689 3,209 2,102 2,875

Waste - total

  • 2017 in metric tons

    61,232
  • 2016 in metric tons

    41,786
  • 2015 in metric tons

    43,756
  • 2014 in metric tons

    49,948

  • 2017 in metric tons

    34,120
  • 2016 in metric tons

    16,729
  • 2015 in metric tons

    -
  • 2014 in metric tons

    -

  • 2017 in metric tons

    27,112
  • 2016 in metric tons

    25,057
  • 2015 in metric tons

    -
  • 2014 in metric tons

    -

  • 2017 in metric tons

    Moved to new category
  • 2016 in metric tons

    Moved to new category
  • 2015 in metric tons

    2,565
  • 2014 in metric tons

    555

  • 2017 in metric tons

    Moved to new category
  • 2016 in metric tons

    Moved to new category
  • 2015 in metric tons

    41,191
  • 2014 in metric tons

    49,393

  • 2017 in metric tons

    9,015
  • 2016 in metric tons

    7,302
  • 2015 in metric tons

    14,942
  • 2014 in metric tons

    9,329

  • 2017 in metric tons

    5,326
  • 2016 in metric tons

    4,093
  • 2015 in metric tons

    12,840
  • 2014 in metric tons

    6,454

  • 2017 in metric tons

    3,689
  • 2016 in metric tons

    3,209
  • 2015 in metric tons

    2,102
  • 2014 in metric tons

    2,875

Water consumption

Water consumption
 
2017 in millions of gallons
2016 in millions of gallons
2015 in millions of gallons
2014 in millions of gallons
Billed water consumption2 528 453 343
355

Water consumption

Billed water consumption2

  • 2017 in millions of gallons

    528
  • 2016 in millions of gallons

    453
  • 2015 in millions of gallons

    343
  • 2014 in millions of gallons

    355

Energy consumption

Energy consumption
 
2017
2016
2015
2014
Electricity (MWh) 543,632 616,396 561,586
763,023
Aircraft (Mainline jet fuel – millions of gallons) 3,356 3,261 3,216
3,183
Natural gas (MM BTUs) 1,401,566 1,279,545 1,579,085 1,204,290

Energy consumption

  • 2017

    543,632
  • 2016

    616,396
  • 2015

    561,586
  • 2014

    763,023

  • 2017

    3,356
  • 2016

    3,261
  • 2015

    3,216
  • 2014

    3,183

  • 2017

    1,401,566
  • 2016

    1,279,545
  • 2015

    1,579,085
  • 2014

    1,204,290

Other

Other
 
2017
2016
2015
2014
Revenue Ton-Miles (RTMs — millions)1 24,796 23,282 22,813
22,176
CO2e/1,000 RTMs1 1.317 1.348 1.372 1.423

Other

Revenue Ton-Miles (RTMs — millions)1

  • 2017

    24,796
  • 2016

    23,282
  • 2015

    22,813
  • 2014

    22,176

CO2e/1,000 RTMs1

  • 2017

    1.317
  • 2016

    1.348
  • 2015

    1.372
  • 2014

    1.423

Footnotes

1Scope 1+2/Mainline only; calculation changed in 2016 based on better passenger weight assumptions; new values are approximately 9% higher

2Does not account for all United locations or locations shared with other businesses (e.g., terminals)