5 Afforestation
Stevens
Afforesting grassy systems for carbon gain using flammable plantation trees could shift the fire regime from lower intensity grass-fuelled fires to high-intensity crown fires. Future changes in climate will worsen this. We highlight the fire risk of trees planted for carbon and costs of fire protection using African examples.
Tree planting projects in previously open ecosystems using non-native flammable species such as pines and eucalypts should not be allowed to begin, or continue, unless the projections for future plantation management, and especially fire protection, have been planned and suitable funding models developed. Without adequate funding, and the skills and technology to protect plantations far into the future, investment in tree planting has a high probability of going up in smoke while adding more carbon to the atmosphere as the trees burn.
Well-planned and executed commercial and state forestry programmes can contribute significantly to national economies. But afforestation of grassy ecosystems with highly flammable non-native plantation trees has long-term costs far exceeding initial planting costs. These costs and consequences of tree planting as ‘Natural Climate Solutions’ to global change need careful scrutiny by those committing their land to major land transformation. Targeting deforested and denuded formerly forest areas offers considerable scope for carbon sequestration and restoration with native species in parts of Africa and South America [14]. However to reduce the risk of inappropriate NBS, it also demands revision of the historical misclassification of African grassy ecosystems which has resulted in large-scale inappropriate ‘forest’ restoration.
Stevens (2023) A trillion trees: carbon capture or fuelling fires?
5.1 Planting Trees
Anderson
The carbon budgets provided by the IPCC already rely on a massive shift away from deforestation and a programme of forestry management, reforestation and some afforestation. So caution needs to be applied to ensure these options are not double counted.
Trees are not a secure carbon sink, as situations such as fire, land use practices, fuel shortages or pest movements can release the carbon back into the atmosphere. Finally, whilst there is immediate popular appeal to planting trees as a store of carbon, in practice, trees need to be considered as part of a rich ecosystem, including their impact on soil carbon cycling.