Tree planting can be fantastic and I have planted trees myself in the hopes of establishing native hedging for wildlife in my garden, so I am not entirely against it, but I want to highlight some of the things that I find troubling.
The fundamental problem that I have with tree planting for offsetting stems from the “nature as a utility” mindset. In a nutshell, you pay your money expecting a tree, that tree requires land and the transaction is a one-off payment that presumably covers the cost of the land, the planting of the tree and any care of the tree that is required throughout their lifetime. It will take about 15-20 years before that tree is a net “carbon sink” (ugh! I hate referring to a tree in this way), assuming the tree survives to maturity. It will likely be in a dense plantation, with trees all of a similar age. Such plantations generally have less biodiversity. They are often not hugely useful habitat and this is especially true of trees that are not native to the area they are planted in and trees that are planted as a monoculture (where a single species is planted). Not to mention, they are not necessarily good neighbours to surrounding habitats.
At the same time, to plant the tree, the soil is dug and disturbed – sometimes even cleared with heavy machinery. Digging the soil releases carbon and damages the vital mycelial network (fungal fibres that work symbiotically with the trees and can extend over vast distances). This mycorrhizal network, often dubbed the “wood-wide web,” is one of the ways that plants communicate and protect themselves as a community. So planted trees, with their disturbed roots and their lack of connection to the “wood wide web” start life at a disadvantage. They can require a lot of aftercare (watering, weeding, protecting and so on). Planting in dense plantations also means they grow in a different way to natural woodlands – generally tall with no low side branches, as they compete with their neighbours to grow towards the light. The trees are vulnerable to drought, deer and rabbits and wildfires, as well as disease.
In contrast, natural succession (which gives rise to trees that nature has planted, if you like) often happens within scrubby undergrowth – brambles and the like, which protect the trees from deer and other grazing animals. They are part of a whole series of layers of vegetation above ground (the woodland floor is often covered in vegetation and layers right the way up to the tree canopy). As I mentioned above, natural trees are often connected to older trees who share nutrients and warnings about “pests” and “diseases” so that they can release chemicals to protect themselves. They are naturally part of a wider ecosystem of animals etc. who evolved with them, so eat the “pests,” carry the seeds, recycle the dead materials etc. This is not so true for non-native trees or trees planted in a way that is less appealing to animal visitors. In addition, ,many forests create their own microclimate. The tree roots draw up water and nutrients from deep below the ground and ensure the health of the whole forest, not just individual trees. So the trees are key to the abiotic systems which help to sustain both them and the life around them. This may be equally true for planted trees, but it may take some time for the initial disruption to both the tree and local environment to heal.
Climate change is creating pressures for woodlands and we are seeing increases in diseases and in fires because the trees are struggling under drought conditions etc. This is true for natural woodland as well as planted trees. Healthy trees are much less susceptible to wildfires and disease.
There have been countless cases of trees being planted in place of existing high value habitat and of communities being displaced from land. A particularly notable horror story was the planting of trees on peatland. However, more widely there is a lack of recognition of the importance of grassland, both as a carbon store and as a habitat, which makes it a frequent target for tree planting schemes.
So, my first issues are centred around biodiversity and providing vital habitat and on what is best for the trees themselves in terms of long-term survival. However, there are also issues associated with climate colonialism and the “great climate land grab.”
In some cases the same tree has been “sold” multiple times and not all trees survive to maturity. In fact, some schemes are plantations where the trees are intended to be felled for timber. Trees planted for timber and then used in building is not necessarily a bad thing at all from a carbon capture and storage perspective if it is done appropriately. We also need to be mindful of land being taken away from food production. Ideally we would be looking more for agroforestry projects, where we are working in much better alignment with nature than some of the current agricultural models.
Instead of looking for offsetting opportunities, I have decided to focus on benefits to communities and to wildlife that might bring the added benefit of a healthy climate. So I support the Wildlife Trusts in the UK who have a number of projects, including restoring kelp forests off the Kent coast and seagrass in places like Yorkshire and the Solent. Both species are really important in carbon capture and the Wildlife Trusts also work to advocate for well-protected Marine Conservation Zones (MCZs). Seagrass captures carbon 35x faster than tropical rainforest – I would be interested to know more about resilience – for example to changing salinity & other climate change effects and they are obviously susceptible to dredging if the MCZ is not well-enforced. The Wildlife Trusts are also involved in restoring peatlands. and are about to launch a project around wildlife gardening.
With Nature-Connected Neighbourhoods, the idea of encouraging wildlife gardening, tree planting, soil health, and wildlife corridors using people’s gardens (where they are eager participants) and where we are replacing paving/astroturf/heavy chemical use seems an entirely appropriate place to have tree planting and will be helping biodiversity as well as protecting residents’ homes from flooding and extreme heat and providing all the mental health benefits of connection with nature.
I also support the World Land Trust, who protect land for local communities.
There is no doubt that we need to have additional ways to capture and store carbon and we also need to reduce emissions as fast as possible. Personally, I do not regard decarbonising other communities as offsetting – frankly it is the least we can do to pay for mitigating climate change as a way to deliver climate justice. That said, it is important, when we “meddle” overseas – however well-intentioned – that we are doing so at the invitation and for the benefit of the local communities – we have a terrible history of imposing our misguided will on others.
I would also like to emphasise that there are doubtless wonderful tree planting projects, planting in the right way in the right places and helping communities in the process. The people offsetting through these projects are often keen to get their emissions as low as possible and give money to plant trees as a way to increase their positive impact. I love these people and projects. I hope that in the not-too-distant future we get to a point where it is easy for the average person to spot which projects are good news and which are greenwashing.
Finally, there is also a video I made a little while back with some experiences from my own garden.