7  Travel emission factors

This travel emissions section provides detail on how to calculate emissions associated with both business travel and staff commuting.

Business travel emissions result from travel associated with (and generally paid for by) the entity. We provide factors for private and rental vehicles, taxis, public transport, air travel, helicopters and accommodation. Business travel emissions are indirect (Scope 3/Category 6: Business travel) if the entity does not directly own or control the vehicles used for travel. If the entity owns or has an operating lease for the vehicle(s) these emissions are direct (Scope 1/Category 1: Purchased goods and services GHG Protocol) and should be accounted for in transport fuels (see Section 3.3).

Staff commuting emissions result from employees travelling between their homes and their worksites. Emissions from staff commuting may arise from the use of private and rental vehicles, taxis, public transport, and air travel. Other emissions associated with working from home can be accounted for in indirect business-related emission factors (see Section 6).

Staff commuting emissions are indirect (Scope 3/Category 7: Employee commuting Section 6.2.3).

7.1 Overview of changes since previous update

Table 7.1: Summary of changes to travel emission factors
Domain Emission factors Size of change Explanation for change
Travel All electric and PHEV passenger vehicles, electric motorcycles 39.10% The change in all-electric and PHEV passenger vehicles, as well as electric motorcycles, is driven by the increase in the latest annual electricity factor, which is used to derive these emissions factors.
Business travel - Hotel Stays -56.7% to +32.1% The Cornell Hotel Sustainability Benchmarking Index has introduced a new hotel type classification, replacing the previous “All Hotels” group into separate “Resort” and “Non-Resort” categories, with the latter used to calculate the MEG 2025 emissions factors. This had a significant impact, with the factors decreasing for 40 out of the 48 countries provided. 26 of these countries decreased by over 20%.
Domestic air travel n/a These factors have not been updated from the previous edition. The information required to update these factors was not available in time for this publication.
International air travel No change The International air travel emission factors are sourced from the UK Greenhouse Gas Reporting: Conversion Factors 2022, published by the UK Department for Energy Security and Net Zero (DESNZ). These factors have remained unchanged in the 2023 and 2024 DESNZ editions, meaning they still reflect air travel data influenced by the COVID-19 pandemic. As a result, we continue to use the 2022 edition factors, which are based on pre-COVID air travel data which provides a more representative period for emissions reporting.

7.2 Passenger vehicles

This section covers emissions from private vehicles for which mileage is claimed, rental vehicles and taxi travel.

Travel, including rental vehicles, staff mileage and taxi travel are indirect (Scope 3) emissions. This is a change in guidance, to align better with leading practice. As with direct (Scope 1) emissions from transport fuels, the most accurate way to calculate emissions is based on fuel consumption data. Fuel-use data are preferable because factors such as individual vehicle fuel efficiency and driving efficiency mean that kilometre-based estimates of emissions are less accurate. However, this information may not be easily available.

The 2024 fleet statistics (Table 7.3, Table 7.4, Table 7.5 and Table 7.6) were taken from the Te Manatū Waka Ministry of Transport Vehicle Fleet Emissions Model. This provides energy (fuel and electricity) use per km travelled by vehicle.

Fuel-use based emission factors are provided in Section 3.3.

If the only information known is kilometres travelled, use the emission factors in this section. Factors such as individual vehicle fuel efficiency and driving efficiency mean that kilometre based estimates of carbon dioxide equivalent emissions are less accurate than calculating emissions based on fuel-use data.

If the vehicle size and engine type are known, use the factors in Table 7.3, Table 7.4, Table 7.5 and Table 7.6. Table 7.7 lists default private car emission factors and Table 7.8 lists the default rental car emission factors based on distance travelled. Table 7.9 lists emission factors for taxi travel based on dollars spent and kilometres travelled.

Table 7.2 details engine sizes and typical corresponding vehicles.

Table 7.2: Vehicle engine sizes and common car types
Engine size Vehicle size Example vehicles Comparative electric vehicles
<1350 cc Very small Fiat 500 Peugeot iOn
1350-<1600 cc Small Suzuki Swift Renault Zoe
1600-<2000 cc Medium Toyota Corolla Nissan Leaf
2000-<3000 cc Large Toyota RAV4 Hyundai Ioniq
>3000 cc Very large Ford Ranger Nissan e-NV200
Table 7.3: Pre-2010 vehicle fleet emission factors per km travelled
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Pre 2010 Fleet
Diesel hybrid vehicle: 1350 – <1600 cc km 0.1823256532 0.1795097807 0.0002690936 0.0025467788
Diesel hybrid vehicle: 1600 – <2000 cc km 0.1932439545 0.1902594577 0.0002852079 0.0026992889
Diesel hybrid vehicle: 2000 – <3000 cc km 0.237569648 0.2339005767 0.000350628 0.0033184434
Diesel hybrid vehicle: <1350 cc km 0.1894659048 0.1865397569 0.0002796319 0.002646516
Diesel hybrid vehicle: ≥3000 cc km 0.2635284404 0.2594584565 0.0003889404 0.0036810435
Diesel vehicle: 1350 – <1600 cc km 0.2033911669 0.2002499546 0.0003001841 0.0028410282
Diesel vehicle: 1600 – <2000 cc km 0.2155709453 0.2122416261 0.0003181602 0.003011159
Diesel vehicle: 2000 – <3000 cc km 0.265017934 0.2609249461 0.0003911388 0.0037018492
Diesel vehicle: <1350 cc km 0.2113563878 0.2080921591 0.0003119399 0.0029522888
Diesel vehicle: ≥3000 cc km 0.2939759494 0.2894357283 0.0004338778 0.0041063433
Motorcycle: <60cc, petrol km 0.0662625199 0.0634818973 0.0008440524 0.0019365703
Motorcycle: ≥ 60cc, petrol km 0.1325250399 0.1269637945 0.0016881047 0.0038731407
Petrol hybrid vehicle: 1350 – <1600 cc km 0.1542578336 0.147784599 0.0019649372 0.0045082974
Petrol hybrid vehicle: 1600 – <2000 cc km 0.1736903139 0.16640162 0.0022124682 0.0050762257
Petrol hybrid vehicle: 2000 – <3000 cc km 0.1929224594 0.1848267128 0.0024574474 0.0056382992
Petrol hybrid vehicle: <1350 cc km 0.1490491275 0.1427944697 0.0018985886 0.0043560691
Petrol hybrid vehicle: ≥3000 cc km 0.2307857458 0.2211011144 0.0029397501 0.0067448813
Petrol vehicle: 1350 – <1600 cc km 0.1953932558 0.1871938254 0.0024889204 0.00571051
Petrol vehicle: 1600 – <2000 cc km 0.2200077309 0.2107753853 0.0028024597 0.0064298859
Petrol vehicle: 2000 – <3000 cc km 0.2443684485 0.2341138362 0.0031127667 0.0071418456
Petrol vehicle: <1350 cc km 0.1887955615 0.180872995 0.0024048789 0.0055176876
Petrol vehicle: ≥3000 cc km 0.2923286113 0.2800614116 0.0037236835 0.0085435163
Table 7.4: Vehicle fleet emission factors per km travelled, 2010–2015
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
2010–2015 Fleet
Diesel hybrid vehicle: 1350 – <1600 cc km 0.1615804965 0.1590850163 0.0002384759 0.0022570043
Diesel hybrid vehicle: 1600 – <2000 cc km 0.1712565049 0.1686115865 0.0002527567 0.0023921617
Diesel hybrid vehicle: 2000 – <3000 cc km 0.2105387861 0.2072871845 0.0003107333 0.0029408683
Diesel hybrid vehicle: <1350 cc km 0.1679083247 0.1653151162 0.0002478151 0.0023453933
Diesel hybrid vehicle: ≥3000 cc km 0.2335439666 0.2299370686 0.0003446865 0.0032622115
Diesel vehicle: 1350 – <1600 cc km 0.1805474809 0.1777590709 0.0002664692 0.0025219408
Diesel vehicle: 1600 – <2000 cc km 0.1913592991 0.1884039093 0.0002824263 0.0026729635
Diesel vehicle: 2000 – <3000 cc km 0.2352332395 0.2316002521 0.0003471797 0.0032858077
Diesel vehicle: <1350 cc km 0.1876180957 0.1847204857 0.0002769047 0.0026207053
Diesel vehicle: ≥3000 cc km 0.2609367369 0.2569067797 0.0003851154 0.0036448418
Electric vehicle: 1350 – <1600 cc km 0.0210148273 0.0204080078 0.0005674308 0.0000393887
Electric vehicle: 1600 – <2000 cc km 0.0236621497 0.0229788867 0.0006389123 0.0000443506
Electric vehicle: 2000 – <3000 cc km 0.0262821801 0.0255232617 0.0007096569 0.0000492614
Electric vehicle: <1350 cc km 0.0203052357 0.0197189063 0.0005482708 0.0000380587
Electric vehicle: ≥3000 cc km 0.031440365 0.0305325 0.0008489354 0.0000589296
Motorcycle: <60cc, electricity km 0.0049924743 0.0048483128 0.000134804 0.0000093575
Motorcycle: <60cc, petrol km 0.0587366048 0.0562717976 0.0007481872 0.00171662
Motorcycle: ≥ 60cc, electricity km 0.0099849487 0.0096966255 0.0002696081 0.0000187151
Motorcycle: ≥ 60cc, petrol km 0.1174732097 0.1125435953 0.0014963744 0.00343324
PHEV (Diesel) – Diesel consumption: 1350 – <1600 cc km 0.0845604598 0.0832544918 0.0001248024 0.0011811656
PHEV (Diesel) – Diesel consumption: 1600 – <2000 cc km 0.0896242376 0.0882400636 0.000132276 0.001251898
PHEV (Diesel) – Diesel consumption: 2000 – <3000 cc km 0.1101819647 0.1084802932 0.0001626171 0.0015390544
PHEV (Diesel) – Diesel consumption: <1350 cc km 0.0878720233 0.0865149108 0.0001296899 0.0012274225
PHEV (Diesel) – Diesel consumption: ≥3000 cc km 0.1222213425 0.1203337326 0.0001803859 0.001707224
PHEV (Diesel) – Electricity consumption: 1350 – <1600 cc km 0.0101392239 0.0098464459 0.0002737737 0.0000190042
PHEV (Diesel) – Electricity consumption: 1600 – <2000 cc km 0.0111094484 0.0107886545 0.0002999712 0.0000208228
PHEV (Diesel) – Electricity consumption: 2000 – <3000 cc km 0.012574282 0.0122111898 0.0003395238 0.0000235683
PHEV (Diesel) – Electricity consumption: <1350 cc km 0.0105565583 0.0102517295 0.0002850424 0.0000197865
PHEV (Diesel) – Electricity consumption: ≥3000 cc km 0.0148720932 0.01444265 0.0004015681 0.0000278752
PHEV (Petrol) – Electricity consumption: 1350 – <1600 cc km 0.0100170677 0.0097278171 0.0002704753 0.0000187753
PHEV (Petrol) – Electricity consumption: 1600 – <2000 cc km 0.011278958 0.0109532693 0.0003045482 0.0000211405
PHEV (Petrol) – Electricity consumption: 2000 – <3000 cc km 0.0125278392 0.0121660881 0.0003382698 0.0000234813
PHEV (Petrol) – Electricity consumption: <1350 cc km 0.009678829 0.0093993453 0.0002613424 0.0000181413
PHEV (Petrol) – Electricity consumption: ≥3000 cc km 0.014986574 0.014553825 0.0004046592 0.0000280898
PHEV (Petrol) – Petrol consumption: 1350 – <1600 cc km 0.0715429404 0.0685407316 0.0009113144 0.0020908945
PHEV (Petrol) – Petrol consumption: 1600 – <2000 cc km 0.0805554927 0.0771750835 0.0010261163 0.0023542929
PHEV (Petrol) – Petrol consumption: 2000 – <3000 cc km 0.089475132 0.0857204214 0.0011397347 0.0026149758
PHEV (Petrol) – Petrol consumption: <1350 cc km 0.0691272048 0.0662263692 0.0008805427 0.0020202928
PHEV (Petrol) – Petrol consumption: ≥3000 cc km 0.1070356719 0.1025440556 0.001363421 0.0031281953
Petrol hybrid vehicle: 1350 – <1600 cc km 0.1367062556 0.1309695508 0.0017413651 0.0039953397
Petrol hybrid vehicle: 1600 – <2000 cc km 0.153927693 0.1474683124 0.0019607318 0.0044986488
Petrol hybrid vehicle: 2000 – <3000 cc km 0.1709715898 0.1637969837 0.0021778371 0.004996769
Petrol hybrid vehicle: <1350 cc km 0.1320902002 0.1265472023 0.0016825657 0.0038604322
Petrol hybrid vehicle: ≥3000 cc km 0.2045267616 0.1959440552 0.002605263 0.0059774433
Petrol vehicle: 1350 – <1600 cc km 0.1731612571 0.1658947643 0.0022057291 0.0050607637
Petrol vehicle: 1600 – <2000 cc km 0.1949750778 0.1867931957 0.0024835936 0.0056982884
Petrol vehicle: 2000 – <3000 cc km 0.2165640137 0.2074761793 0.0027585936 0.0063292408
Petrol vehicle: <1350 cc km 0.1673142536 0.1602931229 0.0021312499 0.0048898807
Petrol vehicle: ≥3000 cc km 0.2590672313 0.2481958032 0.0032999999 0.0075714282
Table 7.5: Vehicle fleet emissions per km travelled, 2015−2020
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
2015–2020 Fleet
Diesel hybrid vehicle: 1350 – <1600 cc km 0.1523914328 0.1500378702 0.0002249138 0.0021286488
Diesel hybrid vehicle: 1600 – <2000 cc km 0.1615171678 0.1590226656 0.0002383825 0.0022561197
Diesel hybrid vehicle: 2000 – <3000 cc km 0.1985654702 0.1954987869 0.0002930619 0.0027736214
Diesel hybrid vehicle: <1350 cc km 0.1583593982 0.1559136652 0.0002337219 0.0022120111
Diesel hybrid vehicle: ≥3000 cc km 0.2202623489 0.2168605748 0.0003250842 0.0030766899
Diesel vehicle: 1350 – <1600 cc km 0.1717168568 0.1690648287 0.0002534361 0.002398592
Diesel vehicle: 1600 – <2000 cc km 0.1819998662 0.1791890252 0.0002686128 0.0025422282
Diesel vehicle: 2000 – <3000 cc km 0.2236339702 0.2201801242 0.0003300604 0.0031237857
Diesel vehicle: <1350 cc km 0.178441646 0.1756857589 0.0002633612 0.0024925259
Diesel vehicle: ≥3000 cc km 0.2480700371 0.2442387957 0.0003661255 0.0034651159
Electric vehicle: 1350 – <1600 cc km 0.0201048461 0.019524303 0.00054286 0.0000376831
Electric vehicle: 1600 – <2000 cc km 0.0226375345 0.021983858 0.0006112462 0.0000424302
Electric vehicle: 2000 – <3000 cc km 0.0251441127 0.0244180569 0.0006789275 0.0000471283
Electric vehicle: <1350 cc km 0.0194259811 0.0188650408 0.0005245296 0.0000364107
Electric vehicle: ≥3000 cc km 0.0300789385 0.0292103858 0.0008121749 0.0000563778
Motorcycle: <60cc, electricity km 0.0050919711 0.0049449365 0.0001374906 0.000009544
Motorcycle: <60cc, petrol km 0.0557618645 0.0534218886 0.0007102949 0.001629681
Motorcycle: ≥ 60cc, electricity km 0.0098108435 0.0095275477 0.000264907 0.0000183887
Motorcycle: ≥ 60cc, petrol km 0.1074379479 0.1029294506 0.0013685452 0.0031399522
PHEV (Diesel) – Diesel consumption: 1350 – <1600 cc km 0.0797515165 0.0785198188 0.0001177049 0.0011139929
PHEV (Diesel) – Diesel consumption: 1600 – <2000 cc km 0.0845273178 0.0832218617 0.0001247535 0.0011807027
PHEV (Diesel) – Diesel consumption: 2000 – <3000 cc km 0.1039159294 0.1023110318 0.0001533691 0.0014515286
PHEV (Diesel) – Diesel consumption: <1350 cc km 0.0828747517 0.0815948181 0.0001223145 0.0011576191
PHEV (Diesel) – Diesel consumption: ≥3000 cc km 0.1152706292 0.1134903675 0.0001701274 0.0016101344
PHEV (Diesel) – Electricity consumption: 1350 – <1600 cc km 0.0097001765 0.0094200764 0.0002619188 0.0000181813
PHEV (Diesel) – Electricity consumption: 1600 – <2000 cc km 0.0106283886 0.0103214856 0.0002869819 0.0000199211
PHEV (Diesel) – Electricity consumption: 2000 – <3000 cc km 0.0120297921 0.0116824225 0.0003248218 0.0000225478
PHEV (Diesel) – Electricity consumption: <1350 cc km 0.0100994396 0.0098078105 0.0002726995 0.0000189297
PHEV (Diesel) – Electricity consumption: ≥3000 cc km 0.0142281038 0.0138172563 0.0003841794 0.0000266681
PHEV (Petrol) – Electricity consumption: 1350 – <1600 cc km 0.00958331 0.0093065844 0.0002587633 0.0000179623
PHEV (Petrol) – Electricity consumption: 1600 – <2000 cc km 0.0107905581 0.0104789723 0.0002913607 0.0000202251
PHEV (Petrol) – Electricity consumption: 2000 – <3000 cc km 0.0119853604 0.0116392738 0.0003236221 0.0000224645
PHEV (Petrol) – Electricity consumption: <1350 cc km 0.0092597177 0.0089923361 0.0002500258 0.0000173558
PHEV (Petrol) – Electricity consumption: ≥3000 cc km 0.0143376274 0.0139236172 0.0003871367 0.0000268734
PHEV (Petrol) – Petrol consumption: 1350 – <1600 cc km 0.0674743019 0.0646428283 0.000859488 0.0019719855
PHEV (Petrol) – Petrol consumption: 1600 – <2000 cc km 0.0759743113 0.0727861456 0.0009677612 0.0022204045
PHEV (Petrol) – Petrol consumption: 2000 – <3000 cc km 0.0843866918 0.0808455112 0.0010749182 0.0024662624
PHEV (Petrol) – Petrol consumption: <1350 cc km 0.0651959488 0.0624600834 0.0008304664 0.001905399
PHEV (Petrol) – Petrol consumption: ≥3000 cc km 0.1009485659 0.0967123873 0.0012858834 0.0029502953
Petrol hybrid vehicle: 1350 – <1600 cc km 0.128931787 0.123521328 0.0016423338 0.0037681252
Petrol hybrid vehicle: 1600 – <2000 cc km 0.1451738433 0.1390818069 0.0018492252 0.0042428111
Petrol hybrid vehicle: 2000 – <3000 cc km 0.1612484557 0.1544818686 0.0020539837 0.0047126034
Petrol hybrid vehicle: <1350 cc km 0.1245782462 0.1193504779 0.0015868784 0.0036408898
Petrol hybrid vehicle: ≥3000 cc km 0.1928953489 0.18480074 0.002457102 0.0056375068
Petrol vehicle: 1350 – <1600 cc km 0.1633135969 0.1564603487 0.0020802895 0.0047729586
Petrol vehicle: 1600 – <2000 cc km 0.1838868682 0.1761702888 0.002342352 0.0053742274
Petrol vehicle: 2000 – <3000 cc km 0.2042480439 0.1956770336 0.0026017127 0.0059692976
Petrol vehicle: <1350 cc km 0.1577991118 0.151177272 0.002010046 0.0046117938
Petrol vehicle: ≥3000 cc km 0.2443341086 0.2340809374 0.0031123293 0.007140842
Table 7.6: Post 2020 vehicle fleet emissions factors per km travelled
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Post 2020 Fleet
Diesel hybrid vehicle: 1350 – <1600 cc km 0.1444720988 0.1422408439 0.0002132257 0.0020180292
Diesel hybrid vehicle: 1600 – <2000 cc km 0.1531235962 0.1507587259 0.0002259944 0.0021388758
Diesel hybrid vehicle: 2000 – <3000 cc km 0.1882466075 0.1853392907 0.0002778323 0.0026294845
Diesel hybrid vehicle: <1350 cc km 0.1501299266 0.1478112911 0.0002215761 0.0020970594
Diesel hybrid vehicle: ≥3000 cc km 0.2088159632 0.2055909693 0.0003081905 0.0029168034
Diesel vehicle: 1350 – <1600 cc km 0.1642241802 0.1616878704 0.0002423777 0.0022939321
Diesel vehicle: 1600 – <2000 cc km 0.1740585017 0.1713703087 0.0002568922 0.0024313008
Diesel vehicle: 2000 – <3000 cc km 0.2138213793 0.2105190807 0.000315578 0.0029867205
Diesel vehicle: <1350 cc km 0.1706555405 0.1680199035 0.0002518697 0.0023837673
Diesel vehicle: ≥3000 cc km 0.2371852426 0.2335221081 0.0003500606 0.0033130739
Electric vehicle: 1350 – <1600 cc km 0.0193672425 0.0188079983 0.0005229436 0.0000363006
Electric vehicle: 1600 – <2000 cc km 0.021807012 0.0211773176 0.0005888209 0.0000408735
Electric vehicle: 2000 – <3000 cc km 0.0242216293 0.0235222109 0.0006540191 0.0000453993
Electric vehicle: <1350 cc km 0.0187132837 0.0181729231 0.0005052858 0.0000350748
Electric vehicle: ≥3000 cc km 0.028975407 0.0281387196 0.000782378 0.0000543094
Motorcycle: <60cc, electricity km 0.0048625099 0.0047221012 0.0001312948 0.0000091139
Motorcycle: <60cc, petrol km 0.0532490495 0.0510145206 0.0006782867 0.0015562422
Motorcycle: ≥ 60cc, electricity km 0.0096935254 0.0094136173 0.0002617392 0.0000181689
Motorcycle: ≥ 60cc, petrol km 0.1061532049 0.1016986202 0.0013521801 0.0031024046
PHEV (Diesel) – Diesel consumption: 1350 – <1600 cc km 0.0756070651 0.074439375 0.0001115881 0.0010561019
PHEV (Diesel) – Diesel consumption: 1600 – <2000 cc km 0.080134682 0.0788970666 0.0001182704 0.001119345
PHEV (Diesel) – Diesel consumption: 2000 – <3000 cc km 0.0985157246 0.0969942288 0.0001453989 0.0013760969
PHEV (Diesel) – Diesel consumption: <1350 cc km 0.0785679949 0.0773545757 0.0001159582 0.0010974611
PHEV (Diesel) – Diesel consumption: ≥3000 cc km 0.1092803541 0.1075926073 0.0001612864 0.0015264604
PHEV (Diesel) – Electricity consumption: 1350 – <1600 cc km 0.0093442979 0.0090744741 0.0002523096 0.0000175143
PHEV (Diesel) – Electricity consumption: 1600 – <2000 cc km 0.0102384559 0.0099428125 0.0002764531 0.0000191902
PHEV (Diesel) – Electricity consumption: 2000 – <3000 cc km 0.0115884449 0.0112538195 0.0003129048 0.0000217206
PHEV (Diesel) – Electricity consumption: <1350 cc km 0.0097289129 0.009447983 0.0002626947 0.0000182352
PHEV (Diesel) – Electricity consumption: ≥3000 cc km 0.0137061053 0.0133103308 0.0003700847 0.0000256897
PHEV (Petrol) – Electricity consumption: 1350 – <1600 cc km 0.0092317189 0.0089651459 0.0002492698 0.0000173033
PHEV (Petrol) – Electricity consumption: 1600 – <2000 cc km 0.0103946757 0.0100945214 0.0002806713 0.000019483
PHEV (Petrol) – Electricity consumption: 2000 – <3000 cc km 0.0115456433 0.0112122539 0.0003117491 0.0000216403
PHEV (Petrol) – Electricity consumption: <1350 cc km 0.0089199985 0.0086624267 0.0002408529 0.000016719
PHEV (Petrol) – Electricity consumption: ≥3000 cc km 0.0138116107 0.0134127897 0.0003729335 0.0000258875
PHEV (Petrol) – Petrol consumption: 1350 – <1600 cc km 0.0638126603 0.0611348429 0.000812846 0.0018649714
PHEV (Petrol) – Petrol consumption: 1600 – <2000 cc km 0.0718513981 0.0688362452 0.0009152435 0.0020999094
PHEV (Petrol) – Petrol consumption: 2000 – <3000 cc km 0.0798072622 0.0764582516 0.0010165854 0.0023324253
PHEV (Petrol) – Petrol consumption: <1350 cc km 0.0616579471 0.0590705495 0.0007853993 0.0018019983
PHEV (Petrol) – Petrol consumption: ≥3000 cc km 0.0954703697 0.0914640766 0.0012161021 0.002790191
Petrol hybrid vehicle: 1350 – <1600 cc km 0.1219350197 0.1168181711 0.001553209 0.0035636396
Petrol hybrid vehicle: 1600 – <2000 cc km 0.137295665 0.1315342264 0.001748873 0.0040125657
Petrol hybrid vehicle: 2000 – <3000 cc km 0.1524979532 0.1460985698 0.0019425198 0.0044568636
Petrol hybrid vehicle: <1350 cc km 0.1178177333 0.1128736614 0.001500763 0.0034433089
Petrol hybrid vehicle: ≥3000 cc km 0.1824274581 0.1747721209 0.002323762 0.0053315751
Petrol vehicle: 1350 – <1600 cc km 0.154638797 0.1481495758 0.0019697899 0.0045194313
Petrol vehicle: 1600 – <2000 cc km 0.1741192688 0.1668125744 0.0022179322 0.0050887623
Petrol vehicle: 2000 – <3000 cc km 0.1933989111 0.1852831708 0.0024635164 0.0056522238
Petrol vehicle: <1350 cc km 0.1494172272 0.1431471226 0.0019032775 0.0043668271
Petrol vehicle: ≥3000 cc km 0.2313557067 0.2216471576 0.0029470103 0.0067615388
Table 7.7: Default private car emission factors per km travelled for default age of vehicle and <3000 cc engine size
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Private car default
Diesel km 0.265017934 0.2609249461 0.0003911388 0.0037018492
Diesel hybrid km 0.237569648 0.2339005767 0.000350628 0.0033184434
Electric km 0.0262821801 0.0255232617 0.0007096569 0.0000492614
PHEV (Diesel) – Diesel consumption km 0.1101819647 0.1084802932 0.0001626171 0.0015390544
PHEV (Diesel) – Electricity consumption km 0.012574282 0.0122111898 0.0003395238 0.0000235683
PHEV (Petrol) – Electricity consumption km 0.0125278392 0.0121660881 0.0003382698 0.0000234813
PHEV (Petrol) – Petrol consumption km 0.089475132 0.0857204214 0.0011397347 0.0026149758
Petrol km 0.2443684485 0.2341138362 0.0031127667 0.0071418456
Petrol hybrid km 0.1929224594 0.1848267128 0.0024574474 0.0056382992

Note: Defaults are based on the average age of the vehicle fleet (pre-2010 for petrol and diesel including hybrids, and 2010–2015 for all plug-in cars) and most common engine size (2000–3000 cc). Source: Te Manatū Waka Ministry of Transport

Table 7.8: Default rental car emission factors per km travelled
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Rental car default
Diesel km 0.1819998662 0.1791890252 0.0002686128 0.0025422282
Diesel hybrid km 0.1615171678 0.1590226656 0.0002383825 0.0022561197
Electric km 0.0226375345 0.021983858 0.0006112462 0.0000424302
PHEV (Diesel) – Diesel consumption km 0.0845273178 0.0832218617 0.0001247535 0.0011807027
PHEV (Diesel) – Electricity consumption km 0.0106283886 0.0103214856 0.0002869819 0.0000199211
PHEV (Petrol) – Electricity consumption km 0.0107905581 0.0104789723 0.0002913607 0.0000202251
PHEV (Petrol) – Petrol consumption km 0.0759743113 0.0727861456 0.0009677612 0.0022204045
Petrol km 0.1838868682 0.1761702888 0.002342352 0.0053742274
Petrol hybrid km 0.1451738433 0.1390818069 0.0018492252 0.0042428111

Note: Defaults assume a 2015−2020 fleet for rental cars and engine size of 1600 – <2000 cc.

We were unable to source more up-to-date data on the New Zealand taxi fleet to produce a representative vehicle type for the taxi (regular) factor. Therefore, this factor is derived from an average of the factors for a petrol, diesel, petrol plug-in hybrid and electric vehicle, for a 2010−2015 fleet and 2000–3000 cc vehicle class.

Table 7.9: Emission factors for taxi travel
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Taxi Travel
Electric km 0.0262821801 0.0255232617 0.0007096569 0.0000492614
Electric – dollars spent $ 0.0072602708 0.0070506248 0.0001960378 0.0000136081
Petrol hybrid km 0.1709715898 0.1637969837 0.0021778371 0.004996769
Petrol hybrid – dollars spent $ 0.0472297209 0.0452477855 0.0006016125 0.0013803229
Regular km 0.1622627558 0.1570991692 0.0014983168 0.0036652697
Regular – dollars spent $ 0.0448239657 0.0433975606 0.0004138997 0.0010125055

7.2.1 GHG inventory development

Entities should gather the activity data on passenger vehicle use with as much detail as possible, including age of the vehicle, engine size, fuel type and kilometres travelled. If information is not available, we provide conservative defaults to allow for overestimation rather than underestimation.

If fuel-use data are available, see Section 3.3.

If fuel-use data are not available, collect data on kilometres travelled by vehicle type and multiply this by the emission factor based on distance travelled for each GHG. If the vehicle is electric and the charging point is within the entity’s boundaries, this is a direct (Scope 1) emission source and emissions are zero. If travel is by rideshare apps (eg, Uber, YourRide, Waka Rider, Ola or Share Your Ride) we recommend using the taxi travel emission factors by distance travelled Table 7.9. If this information is not available, use the taxi emission factors per dollars spent.

Because plug-in hybrids operate on both a fossil fuel and electricity, two separate emission factors should be applied, that for the fossil fuel (petrol or diesel) and that for electricity. The plug-in hybrid electric vehicle electricity factor includes both the electricity and the electricity transmission and distribution loss factor.

Applying the equation E = Q x F this means:

  • E = emissions from the emissions source in kg CO2-e per year
  • Q = distance travelled by vehicle type (km)
  • F = emission factors for correlating vehicle type from Table 3.3 and Table 7.3 to Table 7.9

7.2.1.1 PASSENGER VEHICLES: EXAMPLE CALCULATION 1

An entity has 15 petrol vehicles. They use 40,000 litres of regular petrol in the reporting period.

Example calculation of standard private vehicle consumption
Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 40,000 x 0.0303562842 kg CO₂-e per litre 1,210 kg CO₂-e
CO₂ emissions 40,000 x 2.283122022 kg CO₂-e per litre 91,300 kg CO₂-e
N₂O emissions 40,000 x 0.0696486174 kg CO₂-e per litre 2,790 kg CO₂-e
Total CO₂-e emissions 40,000 x 2.383126924 kg CO₂-e per litre 95,300 kg CO₂-e

Note: Numbers may not add due to rounding.

7.2.1.2 PASSENGER VEHICLES: EXAMPLE CALCULATION 2

An entity owns three post-2020 petrol plug-in hybrid electric vehicles (PHEVs). They are all between 1600 and 2000 cc and travel a total of 37,800 km in the reporting period. We need to capture both the fossil fuel and electricity-based emissions.

For the petrol-based emissions, use the PHEV (Petrol) − Petrol consumption emission factor:

Petrol component
Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 37,800 x 0.0009152435 kg CO₂-e per km 34.6 kg CO₂-e
CO₂ emissions 37,800 x 0.0688362452 kg CO₂-e per km 2,600 kg CO₂-e
N₂O emissions 37,800 x 0.0020999094 kg CO₂-e per km 79.4 kg CO₂-e
Total CO₂-e emissions 37,800 x 0.0718513981 kg CO₂-e per km 2,720 kg CO₂-e

Then also use the PHEV (Petrol) − Electricity consumption emission factor:

Electricity component
Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 37,800 x 0.0002806713 kg CO₂-e per km 10.6 kg CO₂-e
CO₂ emissions 37,800 x 0.0100945214 kg CO₂-e per km 382 kg CO₂-e
N₂O emissions 37,800 x 0.000019483 kg CO₂-e per km 0.736 kg CO₂-e
Total CO₂-e emissions 37,800 x 0.0103946757 kg CO₂-e per km 393 kg CO₂-e

The sum of the above totals is the total emissions:

  • 2,720 kg CO₂-e + 393 kg CO₂-e = 3,110 kg CO₂-e

Note: Numbers may not add due to rounding.

7.2.1.3 PASSENGER VEHICLES: EXAMPLE CALCULATION 3

An entity uses petrol rental cars to travel 12,000 km. It also spends $18,000 on hybrid taxi travel.

  • Total CO2-e emissions from rental cars = 12,000 km × 0.1838868682 = 2,210 kg CO₂-e
  • Total CO2-e emissions from hybrid taxi travel = $18,000 × 0.0472297209 = 850 kg CO₂-e

Note: Numbers may not add due to rounding.

7.2.2 Emission factor derivation methodology

The 2024 fleet statistics were taken from the Te Manatū Waka Ministry of Transport Vehicle Fleet Emissions Model. This provides energy (fuel and electricity) use per 100 km travelled by vehicle.

We split the fleet into four categories and develop average emission factors for these.

  • The pre-2010 fleet is based on the average fuel consumption data from 1970 to 2010. We assume there are no electric vehicles or plug-in hybrid vehicles.
  • The 2010–2015 fleet is based on the average fuel consumption data from vehicles produced between 2010 and 2015.
  • The 2015−2020 fleet is based on the average fuel consumption data from vehicles produced between 2015 and 2020.
  • The post-2020 fleet is based on the average fuel consumption data from vehicles produced from 2021 onwards.

Note that some guidance documents, such as those published by the UK Department for Energy Security and Net Zero (formerly published by the Department of Business, Energy and Industrial Strategy), apply an uplift factor to passenger vehicles. This accounts for the real-world effects on fuel consumption, such as the use of air conditioning, vehicle payload, gradient and weather. We do not apply an uplift factor here, because the Vehicle Fleet Emissions Model is based on real-world driving and fuel use.

For each category, default vehicles are based on the 2000–3000 cc engine size, as it is the most common size for light passenger vehicles in New Zealand based on Motor Vehicle Register open data.

Table 7.10: Fuel consumption in litres per 100 km
CC Unit Pre 2010 Fleet 2010-2015 Fleet 2015-2020 Fleet Post 2020 Fleet
Diesel hybrid vehicle
1350 - <1600 cc Litres 6.801469 6.027592 5.684804 5.389381
1600 - <2000 cc Litres 7.208765 6.388546 6.02523 5.712116
2000 - <3000 cc Litres 8.862288 7.85393 7.407278 7.022344
<1350 cc Litres 7.067828 6.263645 5.907433 5.600441
>=3000 cc Litres 9.830654 8.712115 8.216658 7.789662
Diesel vehicle
1350 - <1600 cc Litres 7.587296 6.735136 6.405719 6.126212
1600 - <2000 cc Litres 8.04165 7.138459 6.789316 6.493071
2000 - <3000 cc Litres 9.886218 8.775131 8.342433 7.976384
<1350 cc Litres 7.88443 6.998898 6.65658 6.366127
>=3000 cc Litres 10.966467 9.733973 9.253995 8.847949
Electric vehicle
1350 - <1600 cc kWh 21.751352 19.313457 18.477148 17.799261
1600 - <2000 cc kWh 24.491458 21.74645 20.804788 20.041506
2000 - <3000 cc kWh 27.203315 24.154362 23.108433 22.260634
<1350 cc kWh 21.016891 18.661314 17.853244 17.198247
>=3000 cc kWh 32.542283 28.894938 27.643733 26.629544
Motorcycle
<60cc, electricity Litres 5.137236 4.588281 4.508276 4.454366
<60cc, petrol Litres 2.780486 2.464686 2.339861 2.234419
>=60cc, electricity Litres 10.274472 9.176562 9.016553 8.908733
>=60cc, petrol Litres 5.560973 4.929373 4.679723 4.468839
PHEV (Diesel) - Diesel consumption
1350 - <1600 cc Litres 3.559435 3.15444 2.975047 2.820443
1600 - <2000 cc Litres 3.772587 3.343339 3.153204 2.989341
2000 - <3000 cc Litres 4.637931 4.110224 3.876476 3.675027
<1350 cc Litres 3.69883 3.277974 3.091556 2.930897
>=3000 cc Litres 5.144709 4.55934 4.300051 4.07659
PHEV (Diesel) - Electricity consumption
1350 - <1600 cc kWh 10.494582 9.318347 8.914845 8.587779
1600 - <2000 cc kWh 11.498811 10.210022 9.767909 9.409545
2000 - <3000 cc kWh 13.014984 11.556262 11.055854 10.650239
<1350 cc kWh 10.926543 9.701894 9.281784 8.941255
>=3000 cc kWh 15.393328 13.668041 13.07619 12.596452
PHEV (Petrol) - Electricity consumption
1350 - <1600 cc kWh 10.368145 9.206081 8.80744 8.484314
1600 - <2000 cc kWh 11.674262 10.365808 9.916949 9.553118
2000 - <3000 cc kWh 12.966913 11.513579 11.01502 10.610902
<1350 cc kWh 10.018051 8.895226 8.510046 8.197831
>=3000 cc kWh 15.511822 13.773254 13.176846 12.693416
PHEV (Petrol) - Petrol consumption
1350 - <1600 cc Litres 3.387493 3.002062 2.831335 2.677686
1600 - <2000 cc Litres 3.81423 3.380243 3.188009 3.015005
2000 - <3000 cc Litres 4.236566 3.754527 3.541007 3.348846
<1350 cc Litres 3.27311 2.900693 2.735731 2.587271
>=3000 cc Litres 5.068042 4.491396 4.235971 4.006097
Petrol hybrid vehicle
1350 - <1600 cc Litres 6.472917 5.736424 5.410194 5.116598
1600 - <2000 cc Litres 7.288337 6.459064 6.091738 5.761156
2000 - <3000 cc Litres 8.09535 7.174254 6.766255 6.39907
<1350 cc Litres 6.254351 5.542726 5.227512 4.94383
>=3000 cc Litres 9.684157 8.582286 8.094212 7.654962
Petrol vehicle
1350 - <1600 cc Litres 8.199029 7.266137 6.852912 6.488903
1600 - <2000 cc Litres 9.231893 8.181481 7.716201 7.306336
2000 - <3000 cc Litres 10.25411 9.087389 8.57059 8.115342
<1350 cc Litres 7.922178 7.020787 6.621515 6.269797
>=3000 cc Litres 12.266598 10.870895 10.252669 9.708073
Source: Te Manatū Waka Ministry of Transport Vehicle Fleet Emissions Model

Vehicle emissions per kilometre are calculated by combining real-world fuel consumption with fuel-specific emission factors expressed in carbon dioxide equivalent (CO₂-e):

\[ \begin{aligned} \text{emissions per km}~(\mathrm{kg~CO_2\text{-}e~km^{-1}}) &= \frac{ \text{fuel consumption}~(\mathrm{L~per~100~km}) \times \text{fuel emission factor}~(\mathrm{kg~CO_2\text{-}e~L^{-1}}) }{ 100 } \end{aligned} \]

Dividing by 100 gives a factor for litres (or kWh) per fuel per km. Use this with the fuel emission factors to calculate emissions per km.

Multiply the values for fuel consumption by the emission conversion factors in Table 3.3.

New Zealand Transport Agency vehicle registration data is unchanged from the 2022 guidance, where the average year of manufacture for the taxi fleet was 2012, and 2015 for the rental fleet1. We assumed a 2010–2015 fleet for taxis and post-2015 fleet for rental cars.

The taxi (regular) factor is derived from an average of the factors for a petrol, diesel, petrol plug-in hybrid and electric vehicle, for a 2000–3000 cc vehicle class. These workings are in Table 7.11.

Table 7.11: Data used for calculating the taxi (regular) emission factor
Vehicle CC Unit CO₂/unit (kg CO₂-e) CH₄/unit (kg CO₂-e) N₂O/unit (kg CO₂-e) Total kg CO₂-e/unit
Electric 2000 - <3000 cc km 0.025523 0.00071 0.000049 0.026282
Diesel 2000 - <3000 cc km 0.2316 0.000347 0.003286 0.235233
Petrol 2000 - <3000 cc km 0.207476 0.002759 0.006329 0.216564
Petrol hybrid 2000 - <3000 cc km 0.163797 0.002178 0.004997 0.170972
Taxi (regular) Average km 0.157099 0.001498 0.003665 0.162263

TaxiCharge NZ Ltd advised that the current average price per kilometre in a taxi is $3.62. North Island’s average rate = $3.4, while South Island’s average = $3.99.

The calculation to develop the emission factors for taxi based by $ spend is:

\[ \begin{aligned} \text{emissions per \$ spend} &= \frac{ \text{emissions per km} }{ \text{average price per km} } \end{aligned} \]

The private car default is based on the average age of light passenger vehicles in the New Zealand fleet, back-calculated to the year of manufacture, with the fuel consumption factors in Table 7.12 applied.

According to Te Manatū Waka Ministry of Transport’s The New Zealand 2024 Vehicle Fleet: Data Spreadsheet2, the average age of light passenger vehicles in 2024 was 15.2 years. This corresponds to a 2009 year of manufacture.

Table 7.12: Energy consumption per 100 km for average light passenger vehicles
Engine type Unit Units per 100 km for a 2000–3000 cc engine
Petrol Litres 10.25411
Diesel Litres 9.886218
Petrol hybrid Litres 6.766255
Diesel hybrid Litres 7.407278
PHEV (Petrol) - Petrol consumption Litres 3.541007
PHEV (Petrol) - Electricity consumption kWh 11.01502
PHEV (Diesel) - Diesel consumption Litres 3.876476
PHEV (Diesel) - Electricity consumption kWh 11.055854
Electric kWh 23.108433

The default emission factor for rental cars is the same as for vehicles in the post-2015 1600–2000 cc category.

7.2.3 Assumptions, limitations and uncertainties

Emission factors from fuel are multiplied by real-world consumption rates for vehicles with different engine sizes. The uncertainties embodied in these figures carry through to the emission factors. For petrol vehicles, we multiplied the real-world consumption by ‘regular petrol’ emission factors from the fuel emission source category. This may overestimate emissions for some and underestimate emissions for others.

According to Te Manatū Waka Ministry of Transport’s The New Zealand 2024 Vehicle Fleet: Data Spreadsheet, the most common size of light passenger vehicle is between 2000 cc and 3000 cc. Therefore, the default emission factors (for vehicles of unknown engine size) are the same as for a <3000 cc vehicle.

The Vehicle Fleet Emissions Model contains uncertainties about the fuel consumption figures provided. Emission factors represent the average fuel consumption of vehicles operating in the real world under different driving conditions, across all vehicle types in that classification.

We assume there are no electric cars or hybrids in the pre-2010 fleet.

7.3 Public transport passenger travel

The emission factors for public transport for passenger travel on buses, trains and a ferry were provided by Auckland Transport. The unit used for these emission sources are passenger kilometres (pkm).

The national average for the bus factor is unchanged from the previous edition.

Table 7.13: Emission factors for public transport
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e) Uncertainties
Bus
Average Bus pkm 0.1545879756 0.1521743592 0.0002806001 0.0021330164 Unknown
Diesel Bus pkm 0.1700575897 0.1674311876 0.0002509872 0.0023754149 Unknown
Electric Bus pkm 0.020624096 0.0200535933 0.00053611 0.0000343928 Unknown
Hydrogen Bus pkm 0.0371185712 0.0361255988 0.0009278171 0.0000651553 Unknown
National Average for Bus pkm 0.155 0.153 0.000125 0.002125 Unkown
Ferry
Ferry Average pkm 0.3462605439 0.3409128294 0.0005110444 0.0048366701 Unknown
Rail
Metropolitan Average pkm 0.0268170819 0.0261757766 0.0005104428 0.0001308624 Unknown
Metropolitan Diesel pkm 0.274856378 0.2706114432 0.0004056593 0.0038392755 Unknown
Metropolitan Electric pkm 0.0202225932 0.0196770957 0.0005132286 0.0000322688 Unknown

7.3.1 GHG inventory development

To calculate public transport passenger emissions, collect data on the type of transport and distance travelled, and multiply this by the emission factors for each gas. Entities could conduct a staff travel survey to quantify these emissions.3

Applying the equation E = Q x F this means:

  • E = emissions from the emissions source in kg CO2-e per year
  • Q = distance travelled, by vehicle type (km)
  • F = emission factors for correlating vehicle type, from Table 7.13.

7.3.1.1 PASSENGER BUS: EXAMPLE CALCULATION

An employee takes a return trip on an electric Wellington bus from the CBD to the airport (9.4 km each way). This happens five times in the reporting year.

Passenger kilometres travelled = 2 trips × 9.4 km x 5 times = 94 pkm

Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 94 x 0.00053611 kg CO₂-e per pkm 0.0504 kg CO₂-e
CO₂ emissions 94 x 0.0200535933 kg CO₂-e per pkm 1.89 kg CO₂-e
N₂O emissions 94 x 0.0000343928 kg CO₂-e per pkm 0.00323 kg CO₂-e
Total CO₂-e emissions 94 x 0.020624096 kg CO₂-e per pkm 1.94 kg CO₂-e

Note: Numbers may not add due to rounding.

7.3.2 Emission factor derivation methodology

7.3.2.1 National average bus

To calculate the emission factor for national average bus travel we used the New Zealand Transport Agency passenger travel data Table 7.14 to estimate the national average loading capacity of seven people per bus.

Table 7.14: National bus passenger kilometres in 2020/21
Region Mode Breakdown 2020/21
New Zealand Bus pkm 534,976,704
New Zealand Bus Service km 122,934,050

The passenger loading per bus for the different regions for 2020/21 is shown in Table 7.15.

Table 7.15: National bus passenger loading by region
Region Unit End Use
National average Passenger/bus 7
Auckland Passenger/bus 7
Bay of Plenty Passenger/bus 3
Canterbury Passenger/bus Missing data
Gisborne Passenger/bus 8
Hawkes Bay Passenger/bus 1
Manawatū-Whanganui Passenger/bus 5
Marlborough-Nelson-Tasman Passenger/bus 6
Northland Passenger/bus 8
Otago Passenger/bus Missing data
Southland Passenger/bus 3
Taranaki Passenger/bus 12
Waikato Passenger/bus 4
Wellington Passenger/bus 20

We then divided the per kilometre emission factor for diesel buses in Table 7.14 by the national passenger/bus loading rate to give the emissions per gas, see Table 7.22.

Table 7.16: Emission factor for national average bus
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Public Transport Vehicle
Diesel bus: ≥ 12000 kg km 1.081684768 1.06497902 0.0015964537 0.0151092939

7.3.2.2 Auckland buses

To calculate the emissions from Auckland buses we used the most recent data available, which were from the year 2024. This information was from Auckland Transport.

Data for the electric and hydrogen buses are in Table 7.17. The distance travelled by electric and hydrogen buses for each 2023 quarter was multiplied by an estimated average bus power rating of 1.08 kWh and 5.76 kWh per kilometre respectively.4 The resultant energy consumption was multiplied by its respective quarterly electricity emission factor (including the transmission and distribution loss factor of electricity) to produce quarterly emissions totals. These totals were then divided by the quarterly totals for passenger kilometres travelled. The final emission factor is weighted based on the quarterly emissions totals and quarterly passenger kilometres travelled.

Table 7.17: Auckland Transport 2023 data for electric and hydrogen buses
Bus type 2023/24 Quarter Distance (km) Fuel consumption rate (kWh/km) Electricity consumption pkm
Electric Q1 1,816,925.055 1.083652 1,968,915.085638 8,769,389.589
Electric Q2 2,214,166.563 1.083652 2,399,386.774931 12,071,135.61
Electric Q3 2,011,190.4 1.083652 2,179,431.181134 13,121,883.46
Electric Q4 2,152,556.505 1.083652 2,332,622.891473 12,454,403.58
Hydrogen Q1 1,089.389 5.761427 6,276.434671 20,565.56657
Hydrogen Q2 1,226.141 5.761427 7,064.32127 20,056.62695
Hydrogen Q3 1,507.266 5.761427 8,684.002299 27,451.51811
Hydrogen Q4 2,045.531 5.761427 11,785.176543 34,286.74539

Data for the diesel buses are in Table 7.18. The annual distance travelled was multiplied by an estimated fuel efficiency of 0.457 litres per kilometre travelled.5The resultant energy consumption was multiplied by the diesel emission factor, to produce an annual emissions total. This total was then divided by the annual passenger kilometres travelled, to produce the final emission factor.

Table 7.18: Auckland Transport 2023 data for diesel buses
Distance (km) Fuel consumption rate (l/km) Fuel consumption (litres) pkm
55,858,421.04 0.457388 25,548,975.392733 402,737,937

7.3.2.3 Auckland trains

To calculate the emissions from Auckland trains we used the most recent data available, which were from the year 2023/24 for electric trains. Diesel trains stopped operating in the region in August 2022. This information was from Auckland Transport.

Data for the electric and diesel trains are in Table 7.19. The diesel fuel used by diesel trains was multiplied by the diesel emission factor in Table 3.3 to produce an annual emissions total. This total was then divided by the annual passenger kilometres travelled, to produce the final emission factor.

The electricity used by electric trains for each year quarter, was multiplied by the respective quarterly electricity emission factors (including the transmission and distribution loss factor of electricity) to produce quarterly emissions totals. These totals were then divided by the quarterly totals for passenger kilometres travelled. The final emission factor is weighted based on the quarterly emissions totals and quarterly passenger kilometres travelled.

The diesel fuel used by diesel trains was multiplied by the diesel emission factor (in Table 3.3) to produce an annual emissions total. This total was then divided by the annual passenger kilometres travelled, to produce the final emission factor.

Table 7.19: Auckland train data
Train type Quarter/Year Unit Fuel consumption per unit pkm
Electric Sep-23 kWh 8,271,508 39,934,857
Electric Dec-23 kWh 7,447,841 38,607,309
Electric Mar-24 kWh 7,598,900 40,232,907
Electric Jun-24 kWh 7,717,790 44,101,512
Diesel 2021/22 Litres 443,997 4,330,313

The train average factor is weighted based on the emission factors for electric and diesel trains and the respective passenger kilometres travelled.

7.3.3 Auckland ferry

To calculate the emissions from ferry travel we used the most recent data available, which were from 2024. This information was from Auckland Transport and covers the 30 ferries operating in the Auckland region.

The annual distance travelled by diesel ferries over the 4 quaters was multiplied by an estimated average fuel consumption rate of 4.84 l/km to estimate the diesel used by public transport ferries in Auckland region.6 The diesel used was then multiplied by the diesel emission factor (in Table 3.3) to produce an annual emissions total. This total was then divided by the annual passenger kilometres travelled, to produce the final emission factor.

Table 7.20: Ferry data
Distance Fuel consumption (litres) pkm
1,462,099 8,930,329 69,136,84

7.3.4 Assumptions, limitations and uncertainties

Limited data are available for areas outside the Auckland region.

These metro commuter rail emission factors are assumed to be appropriate for use on any commuter rail line in New Zealand.

7.4 Public transport vehicles

Public transport vehicle emissions include those from buses. Emissions are calculated for the whole vehicle. This approach is appropriate for transport operators or if a bus is chartered. Table 7.21 details these emission factors.

Buses: We calculated the emissions of different buses using Te Manatū Waka Ministry of Transport Vehicle Fleet Emissions Model data for fuel consumption in litres per 100 kilometres. The guide presents the data in emissions per kilometre.

The change in all-electric and PHEV vehicle emission factors is driven by the increase in the latest annual electricity factor, which is used to derive these emissions factors.

Table 7.21 details the data provided to calculate the emission conversion factors.

Table 7.21: Bus emission factors per km travelled
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Public Transport Vehicle
Diesel bus: 7500 – 12000 kg km 0.7804570209 0.7684034925 0.001151873 0.0109016554
Diesel bus: < 7500 kg km 0.5634573521 0.5547552084 0.0008316042 0.0078705396
Diesel bus: ≥ 12000 kg km 1.081684768 1.06497902 0.0015964537 0.0151092939
Diesel hybrid bus: 7500 – 12000 kg km 0.5522890998 0.5437594407 0.000815121 0.0077145381
Diesel hybrid bus: < 7500 kg km 0.3987296488 0.3925715914 0.0005884833 0.0055695741
Diesel hybrid bus: ≥ 12000 kg km 0.7654524092 0.7536306149 0.0011297278 0.0106920665
Electric bus: 7500 – 12000 kg km 0.0869461467 0.0844355091 0.0023476719 0.0001629657
Electric bus: < 7500 kg km 0.0627714842 0.0609589088 0.001694921 0.0001176544
Electric bus: ≥ 12000 kg km 0.1205041662 0.1170245147 0.0032537871 0.0002258644

7.4.1 GHG inventory development

To calculate public transport emissions, collect data on the type of transport and distance travelled, and multiply this by the emission factors for each gas.

Applying the equation E = Q x F this means:

  • E = emissions from the emissions source in kg CO2-e per year
  • Q = distance travelled, by vehicle type (km)
  • F = emission factors for correlating vehicle type, from Table 7.21.

7.4.1.1 DIESEL BUS: EXAMPLE CALCULATION

An entity charters a diesel bus (<7,500 kg) to travel 500 km. The emissions would be:

Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 500 x 0.0008316042 kg CO₂-e per km 0.416 kg CO₂-e
CO₂ emissions 500 x 0.5547552084 kg CO₂-e per km 277 kg CO₂-e
N₂O emissions 500 x 0.0078705396 kg CO₂-e per km 3.94 kg CO₂-e
Total CO₂-e emissions 500 x 0.5634573521 kg CO₂-e per km 282 kg CO₂-e

This result is for the entire bus.

Note: Numbers may not add due to rounding.

7.4.2 Emission factor derivation methodology

The average age of the bus fleet is 16.4 years (according to Te Manatū Waka Ministry of Transport fleet statistics). Therefore, we applied an average fuel consumption factor for a pre-2010 fleet to the bus fleet from the Vehicle Fleet Emissions Model.

Table 7.22: Fuel/energy consumption per 100 km for pre-2010 fleet buses
Emission source Weight class Unit Pre-2010 units of energy per 100 km
Diesel bus <7500 kg Litre 21.01919
7500 - 12000 kg Litre 29.114137
>=12000 kg Litre 40.351124
Diesel hybrid bus <7500 kg Litre 14.874195
7500 - 12000 kg Litre 20.60257
>=12000 kg Litre 28.554405
Electric bus <7500 kg kWh 57.689474
7500 - 12000 kg kWh 79.906944
>=12000 kg kWh 110.748089

Using the information in Table 7.22 and appropriate emission factor, the equation is:

\[ \mathrm{Emissions\ per\ km}\,(\mathrm{kg\ CO_2\text{-}e\ km^{-1}}) = \frac{ \mathrm{Energy\ use}\,(\mathrm{unit\ per\ 100\ km}) \times \mathrm{Emission\ factor}\,(\mathrm{kg\ CO_2\text{-}e\ unit^{-1}}) }{ 100 } \]

Where:

  • fuel/energy consumption = units of energy per 100 km travelled (L for diesel/hybrid and kWh for electric)
  • emission factor = the emission factor from Table 3.3 or Table 5.2

This allows you to use distance travelled as a unit for calculating emissions. If there are data on the quantity of fuel used, refer to transport fuel emission factors.

7.4.3 Assumptions, limitations and uncertainties

The Vehicle Fleet Emissions Model historical year results have been carefully calibrated to give a total road fuel use that matches MBIE’s road fuel sales figures. The sources used to develop these emission factors will have inbuilt assumptions, limitations and uncertainties. To investigate these, see the documents referenced.

7.5 Air travel

This section covers emission factors for domestic and international air travel for entities seeking to determine the emissions from business travel.

7.5.1 Domestic air travel

This section provides emission factors based on data from 2023. Domestic air travel is a common source of indirect (Scope 3) emissions for many New Zealand entities.

For air travel emission factors, multipliers or other corrections may be applied to account for the radiative forcing of emissions arising from aircraft transport at high altitude (jet aircraft). Radiative forcing helps entities account for the wider climate effects of aviation, including water vapour and indirect GHGs. This is an area of active research and uncertainty, aiming to express the relationship between emissions and the climate warming effects of aviation, but there is yet to be consensus on this aspect.

In this guidance, emission factors with a radiative forcing multiplier refers to the indirect climate change effects (non-CO₂ emissions eg, water vapour, contrails, NOx). Emission factors without a radiative forcing multiplier refers to the direct climate change effects (CO₂, CH₄ and N₂O). If multipliers are applied, entities should disclose the specific factor used including its source and produce comparable reporting. Therefore, avoid reporting with air travel conversion factors in one year and without in another year, as this may skew the interpretation of your reporting.

The decision to apply the Radiative Forcing Index, and to what type of air travel (flight altitude) should be guided by the requirements of your intended use and users.

In terms of the small and medium aircraft, a radiative forcing multiplier may not be required given the lower altitude at which these aircrafts typically fly. However, these emission factors are provided in the tables below for completeness, and for users wanting to take a conservative approach to their reporting.

Table 7.23 provides the emission factors without the radiative forcing multiplier applied. Table 7.24 provides emission factors with a radiative forcing multiplier of 1.7 applied.

Table 7.23: Domestic air travel emission factors without a radiative forcing multiplier
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Without Radiative Forcing factors
Large aircraft pkm 0.1042303604 0.1034434268 0.000020252 0.0007666817
Medium aircraft pkm 0.1198521492 0.1189472719 0.0000232873 0.00088159
National average pkm 0.1146405571 0.1137750271 0.0000222747 0.0008432554
Small aircraft pkm 0.3524624434 0.3405366516 0.0028841629 0.009041629
Table 7.24: Domestic air travel emission factors with a radiative forcing multiplier
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
With Radiative Forcing factors
Large aircraft pkm 0.1766407592 0.1758538256 0.000020252 0.0007666817
Medium aircraft pkm 0.2031152396 0.2022103623 0.0000232873 0.00088159
National average pkm 0.1942830761 0.193417546 0.0000222747 0.0008432554
Small aircraft pkm 0.5908380995 0.5789123077 0.0028841629 0.009041629

We have provided a national average emission factor, and three factors based on the aircraft size: large, medium or small aircraft. A large aircraft in New Zealand would be an Airbus A320neo, A320ceo and A321neo. A medium aircraft has between 50 and 70 seats (ie, regional services on an ATR 72 or de Havilland Q300) and a small aircraft has fewer than 50 seats. If the aircraft type is unknown, we recommend using the national average.

7.5.1.1 GHG inventory development

To calculate emissions for domestic air travel, collect information on passengers flying, their departure and destination airports, flight length, travel class and, if practical, the type of aircraft. Your travel provider may be able to provide this information.

If the type of aircraft is unknown, use the national average emission factors. Calculate distances using online calculators such as www.airmilescalculator.com. Multiply the number of passengers by the distance travelled to obtain the pkm.

Applying the equation E = Q x F this means:

  • E = emissions from the emissions source in kg CO2-e per year
  • Q = passengers multiplied by distance flown (pkm)
  • F = emission factors from Table 7.23 to Table 7.24
DOMESTIC AIR TRAVEL: EXAMPLE CALCULATION

An entity flies an employee on a return flight from Christchurch to Wellington (304 km each way). This happens five times in the reporting year on an aircraft of unknown size. The national average emission factor with radiative forcing is used.

Passenger kilometres travelled = (2 × 304) × 5 = 3,040 pkm

Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 3,040 x 0.0000222747 kg CO₂-e per pkm 0.0677 kg CO₂-e
CO₂ emissions 3,040 x 0.193417546 kg CO₂-e per pkm 588 kg CO₂-e
N₂O emissions 3,040 x 0.0008432554 kg CO₂-e per pkm 2.56 kg CO₂-e
Total CO₂-e emissions 3,040 x 0.1942830761 kg CO₂-e per pkm 591 kg CO₂-e

Note: Numbers may not add due to rounding.

7.5.1.2 Emission factor derivation methodology

We developed emission factors for aircraft type with data from various data sources. We calculated an average emission factor for domestic air travel using data from the 2016, 2020 and 2023 calendar years.

An average emission factor has also been provided where the aircraft type is unknown (see Table 7.23 and Table 7.24). Entities that own aircraft could calculate emissions based on the fuel consumption data.

To calculate the emission factor, first calculate average fuel (kg) per flight for each aircraft:

\[ \begin{aligned} \frac{ \text{average total fuel used (kg)} }{ \text{average number of flights} } \end{aligned} \]

Then calculate average fuel (kg) per passenger:

\[ \begin{aligned} \frac{ \text{average total fuel (kg) per flight} }{ \text{average number of seats} \times 0.8 } \end{aligned} \]

Using this, next calculate fuel per passenger per km:

\[ \begin{aligned} \frac{ \text{average fuel (kg) per passenger} }{ \text{average flight distance (km)} } \end{aligned} \]

The density of kerosene (the assumed aviation fuel) is 0.79 kg/l.7

Emission factors for each aircraft were determined by multiplying the fuel (litres) per passenger per kilometre by the kerosene (aviation fuel) emission factor in Table 3.3

Table 7.25: Calculated emissions, without the radiative forcing multiplier, per aircraft type
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e) Uncertainties
Without radiative forcing factors
Aerospatiale/Alenia ATR 72 pkm 0.1135302273 0.1126730802 0.0000220589 0.0008350882
Airbus A320 pkm 0.1105000756 0.109665806 0.0000214702 0.0008127995
Beechcraft Beech 1900D pkm 0.1790597259 0.1777078345 0.0000347913 0.0013171
British Aerospace Jetstream 32 pkm 0.2277260737 0.2260067541 0.0000442472 0.0016750724
Cessna Light Aircraft pkm 0.5298459145 0.5258456063 0.0001029491 0.0038973591
De Havilland Canada DHC–8–300 Dash 8/8Q pkm 0.2200666746 0.218405183 0.000042759 0.0016187326
FOKKER F50 pkm 0.0870854283 0.086427938 0.0000169207 0.0006405696
Pilatus PC–12 pkm 0.1806018705 0.1792383361 0.000035091 0.0013284435
Saab SF–340 pkm 0.0930101527 0.092307931 0.0000180719 0.0006841498

Note: 2016 or 2020 data unless denoted otherwise. Airbus A320, Aerospatiale/Alenia ATR 72, De Havilland Q300 updated using 2023 data.

Table 7.26: Calculated emissions, with the radiative forcing multiplier, per aircraft type
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e) Uncertainties
With radiative forcing factors
Aerospatiale/Alenia ATR 72 pkm 0.1924013834 0.1915442363 0.0000220589 0.0008350882
Airbus A320 pkm 0.1872661398 0.1864318702 0.0000214702 0.0008127995
Beechcraft Beech 1900D pkm 0.30345521 0.3021033187 0.0000347913 0.0013171
British Aerospace Jetstream 32 pkm 0.3859308016 0.384211482 0.0000442472 0.0016750724
Cessna Light Aircraft pkm 0.8979378389 0.8939375307 0.0001029491 0.0038973591
De Havilland Canada DHC–8–300 Dash 8/8Q pkm 0.3729503027 0.3712888111 0.000042759 0.0016187326
FOKKER F50 pkm 0.147584985 0.1469274947 0.0000169207 0.0006405696
Pilatus PC–12 pkm 0.3060687057 0.3047051713 0.000035091 0.0013284435
Saab SF–340 pkm 0.1576257044 0.1569234827 0.0000180719 0.0006841498

Note: 2016 or 2020 data unless denoted otherwise. Airbus A320, Aerospatiale/Alenia ATR 72 using 2023 data.

For situations where the aircraft type is unknown, average emission factors are also provided for a domestic average, and for large, medium and small aircraft (see Table 7.23 and Table 7.24).

We then calculated a weighted average emission factor for each size category, using the aircraft types within that size range. The weighted averages are calculated using the annual flight domestic distance travelled and the total number of domestic flights for each aircraft type. This method applies an equal weighting of 50 per cent to both distance travelled and number of flights.

  • Large aircraft: A320neo, A320ceo and A321neo
  • Medium aircraft: ATR 72 and Q300
  • Small aircraft: British Aerospace Jetstream 32, Cessna Light Aircraft.

A national average emission factor was calculated using the same weighted average approach described above, this time considering the contribution each of the five large and medium aircraft types make to the overall distance travelled and number of flights.

7.5.1.3 Assumptions, limitations and uncertainties

We assume the fuel for domestic flights is kerosene (aviation fuel) and all the kerosene is combusted. The domestic emission factors are based on fuel delivery data. Therefore, it is not necessary to apply a distance uplift factor to account for delays/circling and non-direct routes (ie, not along the straight-line/great-circle between destinations). However, this should be considered for international air travel.

7.5.2 International air travel

The International air travel emission factors are sourced from the UK Greenhouse Gas Reporting: Conversion Factors 2022, published by the UK Department for Energy Security and Net Zero (DESNZ). These factors have remained unchanged in the 2023 and 2024 DESNZ editions, meaning they still reflect air travel data influenced by the COVID-19 pandemic. As a result, we continue to use the 2022 edition factors, which are based on pre-COVID air travel data which provides a more representative period for emissions reporting.

Because the DESNZ 2022 emission factors were developed using the GWP values from the AR4, the factors presented here have been converted to AR5 GWP values.

Entities wishing to report their international air travel emissions based on distance travelled per passenger could use the International Civil Aviation Organisation (ICAO) calculator. This calculator considers aircraft types and load factors for specific airline routes but does not apply the radiative forcing multiplier (accounting for the wider climate effect of emissions arising from aircraft transport at altitude) or distance uplift factor to account for delays/circling and non-direct routes (ie, not along the straight-line/great-circle between destinations). If using the ICAO calculator to calculate emissions for international air travel, multiply the output by 1.08 to account for the 8 per cent distance uplift factor (see Section 7.5.2.3) and then by 1.7 to apply a radiative forcing multiplier.

If you prefer not to use the ICAO calculator, we recommend the emission factors in Table 7.27 and Table 7.28. These emission factors follow those published online by the UK Department of Business, Energy and Industrial Strategy conversion factors (Conversion factors 2022: condensed set (for most users)) and include a distance uplift of 8 per cent and a radiative forcing multiplier of 1.7.

Table 7.27: Emission factors for international air travel without radiative forcing multiplier
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Without Radiative Forcing
Long–haul (>3700km): Average passenger pkm 0.1019748913 0.10111 0.0000112 0.0008536913
Long–haul (>3700km): Business class pkm 0.2264776349 0.22457 0.0000224 0.0018852349
Long–haul (>3700km): Economy class pkm 0.0781003611 0.07744 0.0000112 0.0006491611
Long–haul (>3700km): First class pkm 0.3123779369 0.30975 0.0000224 0.0026055369
Long–haul (>3700km): Premium economy class pkm 0.1249516362 0.1239 0.0000112 0.0010404362
Short–haul (<3700km): Average passenger pkm 0.0810870389 0.0804 0.0000112 0.0006758389
Short–haul (<3700km): Business class pkm 0.1196371732 0.11863 0.0000112 0.0009959732
Short–haul (<3700km): Economy class pkm 0.0797581463 0.07908 0.0000112 0.0006669463
Table 7.28: Emission factors for international air travel with radiative forcing multiplier
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
With Radiative Forcing
Long–haul (>3700km): Average passenger pkm 0.1929848913 0.19212 0.0000112 0.0008536913
Long–haul (>3700km): Business class pkm 0.4285876349 0.42668 0.0000224 0.0018852349
Long–haul (>3700km): Economy class pkm 0.1477903611 0.14713 0.0000112 0.0006491611
Long–haul (>3700km): First class pkm 0.5911479369 0.58852 0.0000224 0.0026055369
Long–haul (>3700km): Premium economy class pkm 0.2364616362 0.23541 0.0000112 0.0010404362
Short–haul (<3700km): Average passenger pkm 0.1534470389 0.15276 0.0000112 0.0006758389
Short–haul (<3700km): Business class pkm 0.2263971732 0.22539 0.0000112 0.0009959732
Short–haul (<3700km): Economy class pkm 0.1509381463 0.15026 0.0000112 0.0006669463

The emission factors from the UK DESNZ are calculated regarding the indirect and direct climate change effects. For continuity in this guidance, we have categorised the international air travel emission factors by whether a radiative forcing multiplier was applied, as outlined in this section. Further information can be found in paragraphs 8.37 to 8.41 in the 2023 UK DESNZ Methodology Paper for Conversion Factors.

7.5.2.1 GHG inventory development

To calculate emissions for international air travel, collect information on passengers flying, their departure and destination airports, flight length, travel class and, if practical, the type of aircraft. Your travel provider may be able to provide this information. Information on flight distance will be required to determine whether the short- or long-haul factors should be used.

To calculate emissions for international air travel, gather the information on how far each passenger flew for each flight. Multiply this by the factors in Table 7.27 or Table 7.28. Use the specified emission factors for different cabin classes if information is available. If unknown, use the average emission factors.

Applying the equation E = Q x F this means:

  • E = emissions from the emissions source in kg CO2-e per year
  • Q = passengers multiplied by distance flown (pkm)
  • F = appropriate emission factors from Table 7.27 or Table 7.28.
INTERNATIONAL AIR TRAVEL: EXAMPLE CALCULATION

An entity makes five flights from Auckland to Shanghai (9,346 km each way). On the first trip, two people flew return to Shanghai on the same flight in economy class. On the second trip, three people flew return to Shanghai and the cabin classes were not recorded. Long-haul (>3,700 km) emission factors with radiative forcing are used.

For the two people who travel economy class: Passenger kilometres travelled = (2 × 9,346) × 2 = 37,384 pkm

Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 37,384 x 0.0000112 kg CO₂-e per pkm 0.419 kg CO₂-e
CO₂ emissions 37,384 x 0.14713 kg CO₂-e per pkm 5,500 kg CO₂-e
N₂O emissions 37,384 x 0.0006491611 kg CO₂-e per pkm 24.3 kg CO₂-e
Total CO₂-e emissions 37,384 x 0.1477903611 kg CO₂-e per pkm 5,520 kg CO₂-e

For the three people with unknown (average) travel classes: Passenger kilometres travelled = (3 × 9,346) × 2 = 56,076 pkm

Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 56,076 x 0.0000112 kg CO₂-e per pkm 0.628 kg CO₂-e
CO₂ emissions 56,076 x 0.19212 kg CO₂-e per pkm 10,800 kg CO₂-e
N₂O emissions 56,076 x 0.0008536913 kg CO₂-e per pkm 47.9 kg CO₂-e
Total CO₂-e emissions 56,076 x 0.1929848913 kg CO₂-e per pkm 10,800 kg CO₂-e

Total CO2-e emissions from international air travel = 5,520 kg CO₂-e + 10,800 kg CO₂-e = 16,300 kg CO₂-e

Note: Numbers may not add due to rounding.

7.5.2.2 Emission factor derivation methodology

The 2023 UK DESNZ Methodology Paper for Conversion Factors publication discusses the methodology in more detail, including changes over time.

7.5.2.3 Assumptions, limitations and uncertainties

The emission factors in Table 7.27 and Table 7.28 are based on UK and European data. The short-haul emission factor applies to international flights of less than 3,700 km. The long-haul factor applies to flights of more than 3,700 km.

The UK DESNZ endorses a great circle distance uplift factor to account for non-direct (ie, not along the straight-line/great-circle between destinations) routes and delays/circling. The 8 percent uplift factor applied by UK DESNZ is based on the analysis of flights arriving and departing from the United Kingdom. This figure is likely to be overstated for international flights to/from New Zealand (initial estimates from Airways New Zealand suggest it is likely to be less than 5 per cent). In the absence of a New Zealand-specific figure for international flights, we recommend an 8 per cent uplift factor. This figure is comparable to an IPCC publication, Aviation and the Global Atmosphere (refer to section 8.2.2.3)8, which suggests for European flights the average flight distance is about 99 per cent to 1010 per cent greater than the actual flight track distance.

The emission factors refer to aviation’s direct GHG emissions including carbon dioxide, methane and nitrous oxide. There is currently uncertainty over the other climate change impacts of aviation (including water vapour and indirect GHGs, among other factors), which the IPCC estimated to be up to two to four times those of carbon dioxide alone. However, the science is currently uncertain and New Zealand’s Greenhouse Gas Inventory 1990−2023 does not use a multiplier.

International travel is divided by class of travel. Emissions vary by class because they are based on the number of people on a flight. Business class passengers use more space and facilities than economy class travellers. If everyone flew business class, fewer people could fit on the flight and therefore emissions per person would be higher.

7.6 Helicopters

This section provides emission factors for some commonly used helicopters in New Zealand. Business activities that require the use of helicopters might include entities involved in tourism, air transport, agricultural operations, or emergency services.

Table 7.29: Emission factors for helicopters
Emissions Source Unit kg CO₂–e/unit CO₂/unit (kg CO₂–e) CH₄/unit (kg CO₂–e) N₂O/unit (kg CO₂–e)
Helicopter
Bell 206B hours 320.5909112 318.170467 0.0622908427 2.358153331
Eurocopter AS 350B Squirrel hours 465.0289696 461.5180258 0.0903551703 3.420588592
Eurocopter AS 350B3 Squirrel hours 481.1247858 477.4923194 0.0934825889 3.538983721
Robinson R22 Beta hours 123.9417068 122.9771726 0.0248225722 0.9397116614
Robinson R44 hours 179.0278644 177.6346408 0.0358550177 1.357368526

7.6.1 GHG inventory development

These emission factors can be used where the amount of fuel used is not known. Obtaining fuel data will provide a more accurate estimate of your carbon emissions. To calculate emissions from operating helicopters when only the number of operating hours is known.

Applying the equation E = Q x F this means:

  • E = emissions from the emissions source in kg CO2-e per year
  • Q = hours of operating time (hours)
  • F = emission factors for correlating helicopter type, from Table 7.29.

7.6.1.1 HELICOPTER USE: EXAMPLE CALCULATION

An agricultural operation used a Eurocopter AS 350B Squirrel to apply topdressing and other spraying activities. They could not obtain data on the amount of fuel used, but had recorded 10 flying hours over a given year.

Gas Calculation Emissions (kg CO₂-e)
CH₄ emissions 10 x 0.0903551703 kg CO₂-e per hours 0.904 kg CO₂-e
CO₂ emissions 10 x 461.5180258 kg CO₂-e per hours 4,620 kg CO₂-e
N₂O emissions 10 x 3.420588592 kg CO₂-e per hours 34.2 kg CO₂-e
Total CO₂-e emissions 10 x 465.0289696 kg CO₂-e per hours 4,650 kg CO₂-e

Note: Numbers may not add due to rounding.

7.6.2 Emission factor derivation methodology

These emission factors were derived from the Swiss Federal Office of Civil Aviation’s (FOCA) Guidance on the Determination of Helicopter Emissions. This contains air emissions data (non-GHG) for one hour of flying time, including fuel consumption, for a range of helicopter models.This contains air emissions data (non-GHG) for one hour of flying time, including fuel consumption, for a range of helicopter models.

The one-hour emissions values are used, which assume a combination of rotations and cruise per flight-hour.

The fuel consumption (provided in kgs) was converted to litres using assumed densities of 0.804 kg per litre and 0.69 kg per litre, for Jet A1 and aviation gas respectively. Turbine engine helicopters are assumed to use Jet A1 while piston helicopters are assumed to use aviation gas. We then applied the Jet A1 and aviation gas emission factors from Transport fuels section above to determine the emission factor for one hour of operation.

We used the aircraft register on the New Zealand Civil Aviation Authority (CAA) website9 to identify the most commonly registered helicopter models in the country.

7.6.3 Assumptions, limitations and uncertainties

Obtaining the amount of fuel used for helicopter activities would provide a more accurate estimate of carbon emissions, than using this emission factor which is based on operating hours.

A number of factors will influence the accuracy of this emission factor for a given operating hour, such as the cruising speed, the take-off and approach, and the way the helicopter is being used.

Finally, if your entity has a helicopter model that is not provided here, you may wish to choose the model that seems to be the best fit. However, this approach will have limitations, due to variations that include engine operating power, and the size and number of engines.

7.7 Accommodation

Accommodation is an indirect (Scope 3) emissions source associated with business travel. The emission factors for hotel stays have been updated using factors from the 2024 edition of the Cornell Hotel Sustainability Benchmarking Index (CHSB) Index,10 which provides data for the 2022 calendar year.

We obtained the emission factors from the M1 tab of the source spreadsheet, using the median values for all hotels. The factors are in CO2-e and are not available by gas type. For more information on the Cornell methodology, see the Hotel Sustainability Benchmarking Index 2024 guidance document.11

Note these emission factors are based on either AR4 or AR5 GWP values, depending on the country. The reason is some countries submit their emission factors to this study in terms of CO2-e, while other countries break it down into the three main GHG types. In the latter cases, the AR5 GWPs were applied.

The provision of these emission factors can be limited by the availability of data in different countries. If the factor for a certain country is not available in Table 7.30, we recommend using factors from a previous edition of this guidance.

The Cornell Hotel Sustainability Benchmarking Index has introduced a new hotel type classification, replacing the previous “All Hotels” group into separate “Resort” and “Non-Resort” categories, with the latter used to calculate the 2025 emissions factors. This had a significant impact, with the factors decreasing for 40 out of the 48 countries provided. 26 of these countries decreased by over 20%.

Table 7.30: Accommodation emission factors by unit (room per night)
Emissions Source Unit kg CO₂–e/unit
Hotel Stays
Argentina Room per night 15.32536591
Australia Room per night 34.11941583
Austria Room per night 10.0507584
Bahrain Room per night 102.8526699
Belgium Room per night 14.552063
Brazil Room per night 6.757310062
Canada Room per night 10.62474158
Caribbean Region Room per night 43.77455914
Chile Room per night 31.45942816
China Room per night 58.30625072
Colombia Room per night 16.27678951
Costa Rica Room per night 5.631959026
Czech Republic Room per night 20.79396066
Egypt Room per night 51.80399693
Finland Room per night 10.76387424
France Room per night 7.208308927
Germany Room per night 13.03291589
Greece Room per night 26.14054121
Hong Kong Room per night 79.27066469
Hungary Room per night 22.22753295
India Room per night 48.93327122
Indonesia Room per night 52.31393587
Italy Room per night 15.33321042
Japan Room per night 37.39716278
Jordan Room per night 63.32658195
Kazakhstan Room per night 73.75667032
Macau Room per night 130.3482989
Malaysia Room per night 55.17545263
Mexico Room per night 18.43939187
Netherlands Room per night 15.56062372
New Zealand Room per night 10.30784912
Oman Room per night 76.39205262
Panama Room per night 21.19874686
Peru Room per night 16.31695679
Philippines Room per night 55.76161689
Poland Room per night 29.33200281
Portugal Room per night 12.77550297
Qatar Room per night 90.61959799
Saudi Arabia Room per night 72.51266367
Singapore Room per night 23.30541411
South Africa Room per night 52.74867755
South Korea Room per night 45.61996656
Spain Room per night 11.51795365
Switzerland Room per night 7.94082916
Thailand Room per night 43.879308
Turkey Room per night 32.6361285
United Arab Emirates Room per night 54.72447283
United Kingdom Room per night 10.37875541
United States Room per night 14.23988937
Vietnam Room per night 76.44083626

7.7.1 GHG inventory development

To calculate emissions from accommodation during business trips, collect data on the number of nights and the country stayed in.

Applying the equation E = Q x F this means:

  • E = emissions from the emissions source in kg CO2-e per year
  • Q = rooms per night
  • F = emission factors for the country stayed in from Table 7.30.

7.7.1.1 ACCOMODATION: EXAMPLE CALCULATION

An entity sends six people to a conference in Australia. They book three rooms for four nights. 3 rooms x 4 nights = 12

Gas Calculation Emissions (kg CO₂-e)
Total CO₂-e emissions 12 x 34.11941583 kg CO₂-e per Room per night 409 kg CO₂-e

Note: Numbers may not add due to rounding.

7.7.2 Assumptions, limitations and uncertainties

The Hotel Sustainability Benchmarking Index 2024 guidance document outlines the limitations of the study. These include:

  • it is skewed towards upmarket and chain hotels, meaning the data may not be representative of the entire hotel industry, particularly the economy and midscale segments
  • the results do not distinguish a property’s facilities, except for outsourced laundry services, which are taken into consideration. This means it is difficult to compare two hotels because some may contain distinct attributes (such as restaurants, fitness centres and swimming pools) while others do not
  • the data have not been independently verified by a third-party provider.

  1. New Zealand Transport Agency: https://nzta.govt.nz/resources/new-zealand-motor-vehicle-register-statistics/new-zealand-vehicle-fleet-open-data-sets.↩︎

  2. Te Manatū Waka Ministry of Transport: https://www.transport.govt.nz/statistics-and-insights/fleet-statistics/sheet/annual-fleet-statistics.↩︎

  3. GHG Protocol Technical Guidance for Calculating Scope 3 Emissions: https://ghgprotocol.org/sites/default/files/standards_supporting/Chapter6.pdf.↩︎

  4. These network average rates for Auckland were based on Auckland Transport’s GHG inventory of 2023/24.↩︎

  5. The average fuel efficiency was based on Auckland Transport’s GHG inventory of 2023/24.↩︎

  6. The average fuel efficiency was based on Auckland Transport’s GHG inventory of 2023/24.↩︎

  7. Kerosene (ils.co.nz).↩︎

  8. https://archive.ipcc.ch/ipccreports/sres/aviation/121.htm#8223↩︎

  9. https://www.aviation.govt.nz/aircraft/aircraft-registration/aircraft-register-search/.↩︎

  10. https://ecommons.cornell.edu/items/85eddae3-2b5b-41fb-88ad-75a0b53f8424.↩︎

  11. https://greenview.sg/resources/chsb-index/.↩︎