How to achieve ZERO net carbon emissions from vehicles

By Suzanne Orme

It might surprise you that the cost to offset your vehicle emissions is only 2.5-3% of the annual fuel bill, much less than the average fluctuation in fuel prices experienced in the past 12 months.

Its easy to offset the greenhouse gases from the combustion of fuel in your company operated cars, trucks, mobile plant and other vehicles. Here are 3 simple steps to follow to obtain accurate emission estimates and achieve genuine carbon neutrality for your vehicle fleet.

The same steps can be applied to your private vehicles too. Note: to calculate indirect emissions from vehicles your company doesn’t operate such as trains, planes, taxis and rental cars, you’ll need to use different methods than those outlined below.

 Step 1: Gather activity data

Gather all the fuel receipts for the previous financial year and total up the number of litres of each type of fuel used by each vehicle.  It is important to retrieve the data for ALL vehicles for the WHOLE year so the information is complete.   Do not use kilometres travelled and average fuel efficiency for this purpose.  Get the actual consumption of fuel to achieve the most accurate estimate. Do keep records for reporting and verification purposes.

Example: Small fleet of trucks

During the 2014-15 financial year a company purchased 100,000 litres of E10 petrol and 500,000 litres of diesel for the vehicle fleet.  The information was readily available from the fuel cards issued to staff with company cars and trucks.

Step Two: Calculate emissions

Next simply convert the number of litres into kilolitres by dividing by 1,000, then multiplying this figure by the emission factor in the table below to get the number of tonnes of CO2-e.  The little “e” means that the total will include the other greenhouse gases – methane and nitrous oxide as well as carbon dioxide. If any of the vehicles have used biodiesel such as B5, B20 or B100 or a petrol/ethanol blend such as E10, just calculate the proportion separately then add up the total. Too easy!

Example: Small Fleet of trucks

The table shows that the total emissions from the car fleet in the above example were estimated to be 1,565 tonnes.

Type of fuel used

Kilolitres of fuel


Emission Factor GHGs *

Tonnes of CO2-e













LNG (light duty vehicle)


LNG (heavy duty vehicle)











* Source of emission factors:  Table 4: Fuel combustion emission factors – fuels used for transport energy purposes. The National Greenhouse Accounts (NGA) Factors, December 2014  prepared by the Australian Government Department of the Environment for use by companies and individuals to estimate greenhouse gas emissions. 

Step Three: Purchase offsets

Go on-line to find a reputable carbon offset retailer, then purchase offsets for the number of tonnes you calculated in step 2.  To avoid the risk that the offset does not represent genuine emission reduction (or removal from the atmosphere), make sure that you only EVER purchase verified carbon offsets. Reliable verifiers include, but are not limited to, VCS, NCOS, Gold Standard, Gold Power and Greenfleet. Some sellers will allow you to choose the actual project that your money will help fund such as Tasmanian native forest protection, Australian wind energy or sustainable development projects in third world countries.  Currently carbon credits will cost between $13 and $33 per tonne. For more information and advice go to the independent source: 

Example: Small Fleet of trucks

The annual fuel bill in our example was $840,000 ($1.40/litre average fuel price x 600,000 litres) and at $15/tonne, the carbon credits will cost 2.8% of the total fuel bill .

Call us on +61 294111764 if you need help



4 thoughts on “How to achieve ZERO net carbon emissions from vehicles

  • BL396
    August 15, 2015 at 4:42 pm

    Hello Suzanne
    Appreciate that this would be a good thing to do but constant pressure to keep running costs down means that in reality even a “2.5 – 3%” addition to fuel prices would be unrealistic for all but a very few small businesses.

    • Suzanne Orme
      August 15, 2015 at 4:56 pm

      Its not unrealistic from the point of view that in the last 12 months the average pump price in Australia ranged from $1.10AUD to $1.50AUD, thats a 27% difference. See The savings gained from the dip in fuel prices in February 2015 would have simply been channelled into other parts of the business. What to spend money on depends on the company’s philosophy and corporate strategy. Some very large corporations are using carbon offsetting to reach targets or become carbon neutral. This includes Microsoft and two of the biggest carmakers in the US, General Motors and Chevrolet. Voluntary action to address the climate change issue has become more and more commonplace. See

  • Corinne Simpon
    August 20, 2018 at 3:33 am

    here! Good luck for the next!

  • Kindra Tamburri
    September 7, 2018 at 3:41 pm

    I like the helpful info you provide in your articles. I will bookmark your weblog and check again here regularly.

Comments are closed.

Theme BCF By aThemeArt - Proudly powered by WordPress .
BACK TO TOP This site is protected by WP-CopyRightPro