New Zealand forest

Carbon offset schemes

Carbon offset schemes may ease your conscience. But how do you know they aren't just smoke and mirrors? We explain how they work, compare 4 voluntary schemes, plus provide tips on how you can reduce your carbon footprint.

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Last year, cycling historian and guidebook writer Jonathan Kennett organised the inaugural Tour Aotearoa. The tour had eager bike-packers from all over the world setting off from Cape Reinga with the aim of reaching Bluff inside 30 days.

The tour was a labour of love for Mr Kennett. He didn’t charge entry fees, instead requiring entrants to offset the greenhouse gas emissions resulting from their travel to and from the event.

UK entrants booking return flights to Auckland and transport in-country had to pay about $230 to Kiwi company Enviro-mark Solutions. By Enviro-mark’s calculations, the money compensated for more than 7000kg of greenhouse gas emissions per passenger spewed into the atmosphere during the 36,000km round trip.

Mr Kennett chose Enviro-mark because he rated the pedigree of its carbon offsets. It’s one of several companies offering consumers offsets. Air New Zealand and Jetstar also flog their own to passengers during online booking. But how can you be sure the money you spend on these schemes isn’t going up in smoke?

How it works

The idea behind carbon offsetting is to invest in projects that represent a sufficient reduction in emissions to balance out the activity you’re doing. For example, you could offset the 7 tonnes of greenhouse gases from an Auckland-London return flight by planting a forest big enough to vacuum up all those emissions.

Offsetting schemes aim to compensate for carbon dioxide (CO2) and other key greenhouse gases. Each offset, also referred to as a carbon credit, represents one tonne of carbon dioxide equivalents (CO2e).

Personal air travel has been a focus of carbon offset schemes. In addition to CO2, jet engines leave behind other emissions including water vapour from contrails, which add to the greenhouse effect via a process called “radiative forcing”. Some calculators use a radiative forcing multiplier to take this into account.

What on earth is an offset?

Projects that commonly serve as the basis for offsets include:

  • Forestry: Which removes CO2 from the atmosphere, serving as a carbon sink. Forestry is the basis for all carbon credits generated in New Zealand.

  • Renewable energy: From investing in power sources such as wind farms or solar PV in lieu of fossil fuel-fired stations.

  • Energy-efficiency projects: Aimed at reducing overall energy use and therefore carbon emissions. An example is distributing fuel-efficient stoves in developing countries.

Carbon credentials

Carbon offsetting has been dogged by criticism. There’s no government regulation of voluntary carbon offset schemes and there’s little stopping a company claiming to be selling offsets that don’t exist. It’s up to the schemes to choose how they verify the offsets they sell.

To be legitimate, the projects behind carbon offsets must be:

  • Permanent. The lifespan of some greenhouse gases is 100 years. If you purchase carbon offsets generated by a reforestation project, there’s a serious risk the land could be logged within the next century, so there’s a good chance you won’t fully balance your emissions.

  • Additional. If the project would have gone ahead without funding from carbon credits, then it’s bogus.

Sourcing credits from projects that have robust third-party certification is your best bet for ensuring you’re making a real dent in your carbon emissions.

Gold Standard certification is typically used for energy-efficiency and renewable energy projects. It’s regarded as a rigourous certification.

The Verified Carbon Standard (VCS) is the most widely used for certifying voluntary carbon offsetting projects. It’s a well-regarded standard, able to be used for forestry as well as renewable energy and energy-efficiency projects.

The ISO14064-2 standard provides guidelines for monitoring, reporting and verifying greenhouse gas emissions and offsets. It’s significantly less onerous than Gold Standard and VCS certification.

Some New Zealand schemes also sell offsets generated by the Permanent Forest Sink Initiative (PFSI), run by the Ministry for Primary Industries. The project promotes planting new permanent forests on private land. PFSI participants agree to covenant the forests in perpetuity, though they have the right to terminate the covenant after 50 years. Limited harvesting is also allowed.

Cutting your carbon

If you’re eager to shrink your overall carbon footprint, offsetting is far from your only option.

  • Reducing food wastage. A 2015 report by WasteMINZ found the average Kiwi household chucks out $563 worth of food annually. Stopping this food waste would have the same impact as avoiding 325,000 tonnes of carbon dioxide emissions a year nationwide.

  • Eating less red meat and dairy. 49% of New Zealand’s greenhouse gas emissions come from agriculture. Dr Nick Wilson, from the University of Otago’s department of public health, suggests one of the best ways of reducing your carbon footprint is shifting towards diets that use less red meat, or going vegetarian.

  • Shaking up your daily transport routine. Taking public transport, walking or cycling to work just 1 or 2 days every week can shrink your carbon footprint.

A 30km commute generates the following levels of CO2e emissions:

Transport COe emissions
Large car (2.5L and above) 9.2kg
Small car (less than 1.6L) 5.4kg
Motorbike (300cc) 3.2kg
City bus (per passenger) 3.0kg

Voluntary carbon offsetting schemes

We asked 4 voluntary carbon offsetting schemes for information on the projects backing their carbon credits and how these projects are verified.

We also calculated the cost of flying from Wellington-Auckland return according to each scheme’s calculator, both in terms of kilograms of emissions and dollar value.

Of the 4 schemes, Enviro-mark, Jetstar and Air New Zealand sell carbon credits eligible to be traded under schemes, such as New Zealand’s Emissions Trading Scheme (ETS). The ETS requires certain industries to buy credits to compensate for their emissions. The exception is Ekos Rainforest Carbon Boutique, which focuses entirely on voluntary offsetting, selling credits based on its own projects and verified by third-party agencies.

Enviro-mark Solutions

Wellington-Auckland return

Emissions: 276kg (kg/CO2e)

Offset cost: $4.28A

Note: AOffsetting costs vary depending on the source of credits chosen. NZ PFSI reforestation credits cost $4.28 for the Wellington-Auckland return trip. Gold Standard solar cooking stove credits and VCS solar power credits from Mexico cost $2.88 for the journey, while VCS wind farm credits are the cheapest, at 88¢.

What it offers: Offset calculators for individuals and businesses, along with certification programmes for businesses wanting to go carbon neutral. The individual calculator allows you to work out the carbon impact of a range of activities. This includes travel and transport along with waste disposal and energy use.

What you get: Enviro-mark lets you choose from a range of Gold Standard and VCS offsets. You have the option to purchase credits from renewable energy, energy-efficiency or reforestation projects. The renewable energy projects include a wind farm in China and a solar plant in Mexico, both are VCS-certified. The energy-efficiency scheme is Gold Standard, involving the distribution of solar cookers in China to replace traditional coal-fired cooking stoves. Reforestation offsets come from PFSI forests.

Note: A new calculator is being launched this month. Our assessment is based on a trial of this calculator.

Jetstar Carbon Offsets

Wellington-Auckland return

Emissions: 114kg (kg/CO2e)

Offset cost: $1.20

What it offers: When booking a flight, you can tick a box to offset your CO2 emissions. The calculator will automatically estimate the offset cost and add it to the ticket price.

What you get: Carbon credits are from a range of Gold Standard and VCS projects in New Zealand, Australia, Papua New Guinea and Thailand. All credits are also certified under the Australian government’s National Carbon Offset Standard, its official response to UN climate change obligations.

Ekos Rainforest Carbon Boutique

Wellington-Auckland return

Emissions: 149kg (kg/CO2e)

Offset cost: $3.38B

Note: BCost increases to $6.38 for 281kg if you include radiative forcing.

What it offers: Carbon offsetting for individuals and businesses. Offsets are available to purchase from a menu of pre-calculated domestic flights or driving a vehicle for 10,000km. You can also receive a free quote for offsetting household emissions or international flights.

What you get: Offsets are generated from 4 projects run as partnerships between Ekos and indigenous forest owners: the Rarakau Rainforest Conservation Project in western Southland, and 3 rainforest protection programmes in Vanuatu, Fiji and the Solomon Islands. The New Zealand offsets are audited against ISO14064-2, while the Pacific projects hold the “Plan Vivo” standard. None of them hold Gold Standard or VCS certification.

Air New Zealand Carbon Offsets

Wellington-Auckland return

Emissions: 134kg (kg/CO2e)

Offset cost: $4.80

What it offers: When booking a flight, you can use Air New Zealand’s calculator to estimate and offset the CO2 emissions from your flight, or donate to the Air New Zealand Environment Trust.

What you get: Carbon credits are generated from PFSI native reforestation projects owned and managed by the Native Forest Restoration Trust. If you donate to the Air New Zealand Environment Trust, part of your money goes towards replanting Mangarara Station in Hawke’s Bay.


Of the 4 offsetting schemes, Enviro-mark and Ekos are the only ones to take into account radiative forcing (though this is an optional extra with Ekos). This means they better reflect the level of emissions produced by air travel compared with Air New Zealand and Jetstar calculators. Enviro-mark has the added benefit of letting you choose the project you wish to support.

Consumer NZ CEO Sue Chetwin is on the Industry Advisory Panel for Enviro-mark Solutions.

By George Block
Technical Writer