Planting trees in the Cambrian Mountains to offset carbon emissions


The Welsh Government has declared a climate emergency.  It has also instigated the creation of a National Forest.  At the same time, a belief has emerged that carbon dioxide emitted through human activities today can be “offset” by planting trees which will safely capture and sequester that carbon. As a result, a trend has developed for land in mid-Wales including in the Cambrian Mountains to be acquired for the purpose of planting trees.  The Trustees of the Cambrian Mountains Society, having reviewed evidence as to the suitability of the region for planting trees and the current state of scientific discussion as to the effectiveness in sequestering carbon of tree planting, compared to mechanisms such as peatland restoration, has adopted this policy.


  • The primary focus for carbon sequestration in the Cambrian Mountains should be on preserving and restoring the existing blanket bogs and peatlands of the uplands. This will enhance the natural processes by which those ecosystems already capture and sequester substantial quantities of carbon from the atmosphere.  See our position on peatland preservation in the Cambrian Mountains .
  • Land which has in the past been planted with conifers for commercial forestry purposes can also contribute to carbon capture through natural regeneration with native trees, shrubs and grasses. These processes, which will also help native insects, birds and animals to thrive, are more appropriate to the ecology and climate of the Cambrian Mountains than planting non-native trees on untilled land.   They are also relatively low cost.
  • Some mixed woodland planting may be appropriate, in particular on land which has in the past been conifer plantations, to assist with the economic need for production of timber and wood products and provide verifiable carbon credits, provided that it is done and managed long-term in accordance with the Woodland Carbon Code.
  • The planting of conifer monocultures on currently grazed or unfarmed land for the purpose of carbon offsetting is not appropriate given the economic and scientific uncertainties and limitations associated with the use of tree planting to offset carbon emissions, and the impact on local communities of the removal from agriculture of land currently being farmed.

Discussion summary

No mechanism is yet available for carbon offsetting which actually cancels out carbon emissions at the same time as they are taking place.  Instead, the existing proposed systems, including mass planting of trees, generally involve removing carbon from the atmosphere after – and at a much slower rate than – the activity which has led to the emissions being generated, while ongoing human activity continues to increase the concentration of carbon dioxide in the atmosphere.   Thus, carbon offsetting is no panacea for the problem of global warming.  The area which would need to be planted with trees to offset the estimated lifetime emissions of the current population of the UK is greater than the land area of the UK.  We believe that this offsetting approach is arguably misguided compared to the fundamental need to reduce the carbon emitted through current and future human activity, and as a result the claimed objective does not justify the adverse impact on the landscape and biodiversity of the Cambrian Mountains.

For further information, see our Discussion document on carbon sequestration and offsetting through tree planting.