Tree planting to offset your carbon footprint

One of the downsides of joining an international biodiversity research expedition is that just getting there emits carbon dioxide from the flights. By helping the biodiversity and carbon research teams in these areas it can be argued that you are providing data that are used to protect those forests and avoid their deforestation and much greater carbon loss. However, some participants, as well as those traveling for tourism only or small businesses want to directly offset their carbon footprint by contributing to tree planting schemes. These schemes are not independently certified (ie there are no carbon credits associated with them – see Using Carbon Credits to reforest Mangroves ). When considering supporting tree planting schemes you should take into account the following points:

1. Spacing

If the trees are being planted out as seedlings then the spacing between then is often just a few inches. As the trees grow they then need to be thinned out and in mature rainforests a minimum spacing of 5m is a more normal spacing, meaning that the vast majority of the seedlings planted will be destroyed. One of the more popular and alliterative schemes is called the Trillion Tree Initiative. If 1 trillion trees were planted at 5m spacing then it would occupy 2.5 billion ha of land which is more than the 1.5 billion hectares of land deforested since the Industrial Revolution. Note since the 1700’s the world population has grown from around 600 million to over 7 billion, which means we need more land to produce the food needed to sustain the population. Even with the huge growth in farming efficiency, it means that some of the 1.5 billion hectares lost since 1700 will no longer be available for reforesting. Perhaps the best we can do it to target the 0.9 billion ha identified by Bastin et al (2016) as potentially available for reforestation and which once reforested would sequester two thirds of the carbon dioxide emitted since the Industrial Revolution (the most cost-effective way of combating climate change?).

2. Size at Planting

A more effective way of planting is to grow the seedlings on in tree nurseries until 1m or 2m in height and then plant them out at 5m spacing during the wet season. This avoids the thinning losses but requires additional manpower to weed around them for the next 2 – 3 years as they become established and can outcompete the quick growing grasses found in many areas of the Tropics.
3. Species used

Planting agroforestry species helps providing income for impoverished local communities and to some increases in biodiversity. Replanting native forests has the advantage that it is much better for restoring biodiversity but doesn’t provide the same income to local communities, so requires compensation payments for the opportunity loss in order to ensure the forests remain intact. Many tree planting schemes concentrate on agroforestry because of the lack of need to compensate local communities, and the schemes can be operated more cheaply. However, please ask what agroforestry schemes are being used. Planting oil palm will sequester carbon but is very poor for biodiversity.
4. Land ownership

Even more important than the species used, size at planting and species used is where the trees are being planted. Is it on state land that has protected status? If not and is on private land are there agreements in position that will ensure the landowners are maintaining those trees for the next 25+ years?

Opwall tree planting scheme in Sulawesi

During the pandemic Opwall funded the development of tree nurseries with our partners in SE Sulawesi partly to provide them with some income (there are no govt income support schemes for rural communities in Indonesia during pandemic times) but also to develop the resources to start reforesting some of the damaged areas on Buton Island. This initiative employed local communities to collect seedlings and seeds from the adjacent forests and grow them on in village-based nurseries. 30,000 trees comprising at least 30 species of native trees have been grown on in this way. In 2020 we opened a Virgin Money donation scheme for these trees which has reached 1.5m to be planted out. Local community members carried the trees back into areas of conservation forest that in the past had been damaged by illegal logging and planted this mix of native species at 5m spacing.

Planting stops during the dry season (June to November) but continues throughout the wet season (December to May).
Reports of how the planting is proceeding can be seen at here. Those joining one of the Opwall Sulawesi biodiversity research projects can also see the tree planting areas for themselves!