Considering trees for carbon offsetting

Kathryn Fraser

Creating integrity in your Carbon Assets

When considering carbon offsetting and the management of those assets, you need to ensure integrity in the scheme that you choose. You need to ensure creditability to consider the long-term effects of that carbon offsetting project, and it’s in your economic interest to do so. Consider the whole natural capital approach and look to soils, biodiversity and water and ensure that you don’t lose out in the gold rush.

Trees are often heralded as the ideal solution to climate change and carbon sequestration. Planting trees without consideration to things such as unnatural densities or monocultures of even-aged straight lines or on previously unforested and often unsuitable land, could cause more harm than good. There may be degradation of blanket bog, increased forest fire risks, displacement of native species or soil degradation.

Trees are incredible organisms, sequestering carbon and holding onto it in their woody bark for decades, perhaps centuries, a large tree can sequester up to 40kg of carbon a year. However, they are not the only thing that will do so. Other habitats such as saltmarshes, peat bogs and wildflower meadows can also do the same, holding carbon in the sediment layers but they are often overlooked as solutions. Peat bogs are especially important, locking carbon away for millennia in some cases.

Heterogeneity is key, both by having a mosaic of habitats doing their own bit but also heterogeneity within the structure of forests with different ages and species of native tree present throughout, allowing the forest to function as an ecosystem and not just as a crop.

Planting trees in some areas may cause more harmful gas emissions and degrade land resulting in the amplification of the climate breakdown. Planting vast swathes of even-aged monoculture forest can damage land through removal of water, loss of nutrients from bad drainage, as well as displacement of species that should inhabit the area, reducing biodiversity overall. Even-aged grid structures can also increase fire risks, something that must be avoided in a climate that threatens more fires year on year and something which will cause mass carbon release.

All the above issues have been seen in Scotland, one such example is seen in the Flow Country in the North West of Scotland. In the 1970s, detrimental commercial tree planting on peat bogs due to tax breaks led to blanket bogs devoid of water, which dried out the peat. The consequent nutrient run off from erosion and the loss of dissolved organic carbon as well as carbon sequestration benefits of blanket peat bog have led to a lot of previously locked carbon being released - the opposite of what a blanket bog should be achieving.

Choosing forestry as a crop for carbon offsetting should consider all of the above aspects, as well as the long term use for the crop. Very recently there has been the shift to a Natural Capital approach to agriculture and by giving proper consideration from the outset, better management and indeed gain from carbon and biodiversity assets can be achieved. It is likely other carbon codes, aside from peatland and forestry, will open up more revenue streams in carbon financing in the future. In our view, consulting experts at the start of a Natural Capital project will ensure you maximize your assets and stay ahead of the game in this rapidly moving market. If you have a Natural Capital project, get the experts onboard and speak to a member of the Nevis team -after all it's in our nature

Peatland, Climate Change, Carbon offsetting, Carbon codes, Natural Capital