Why carbon sinks are important for urgent action on climate change

As humans consume more and more, we release carbon dioxide into the atmosphere, warming the earth and harming our environment at a rate that is unprecedented and unsustainable. This is no longer hypothetical  it’s happening.

An effective way of utilizing excess carbon is through carbon sinks, which store carbon for indefinite periods of time. Examples are kelp farms and forests. Ocean and land sinks absorb around half of the CO2 emissions produced by human activities; as polluters look for ways to reduce the impact of their actions, carbon sinks have become more widely understood.

The government estimates that in 2017 New Zealand forests sequestered  or ‘sucked up’  24 million tonnes of carbon from the atmosphere, offsetting about a third of the country’s total emissions. There is opportunity for forests to work even harder. Historically, New Zealand was covered in trees; we have lost two thirds of our natural tree coverage to human settlement, when land was cleared for pasture and towns. 

Carbon offsetting through permanent forestry has multiple benefits  trees don’t just suck up carbon, they can improve soil and water quality, prevent erosion and promote biodiversity, creating habitats for animals. This is especially true in the case of natives. 

“Land use and land use change is a huge part of the climate change issue that people often forget about,” says Ollie Belton of Permanent Forests NZ, which links companies like Z Energy with landowners who have carbon credits to sell. PFNZ has around 11,000 hectares of permanent forest throughout the country on its portfolio. 

“Voluntary action is growing and that's great,” says Ollie of carbon offsetting through forestry. “People can see that there’s an opportunity to do this instead of clearing land for farming.”

Z is one of the biggest players in the voluntary carbon offsetting space. They have bought into 20 forest schemes, with about half being pure native forests and half being a mixture of native and exotic trees, including Douglas fir, eucalyptus and Pinus radiata. 

There are two ways trees can be used to offset carbon  through plantation forestry or permanent forestry. Plantation forestry is usually a monoculture (most often the fast-growing Pinus radiata), and while the trees provide habitat for kiwi and falcons and help stabilise the soil, after 25 to 30 years they are harvested, and all that good work is undone. 

With permanent forestry, the land is locked up and protected for 50 to 100 years and the sole income derived from it is carbon offsets. Once those units are bought, they are taken out of circulation, meaning that they cannot be used for compliance, says Ollie. 

The government’s Emissions Trading Scheme (ETS) is the main way New Zealand meets its obligations to reduce emissions. It puts a price on emissions and provides a financial incentive for businesses to reduce their impact, through cutting emissions or offsetting them. To offset them, a business must buy emission units, with each unit representing one metric tonne of carbon dioxide. 

Z Energy’s initial contribution to permanent forests was the largest single voluntary purchase of units from permanent forest sinks in New Zealand. “We are very intentionally going above and beyond our ETS obligation,” says Camilla Read, Sustainability Champion at Z.

“It is all about impact. I’m really conscious that, because of our size, the way we do business and our values that we have significant impact. Supporting permanent forests is about that impact being underpinned by integrity and validity.”