We have a tree planting problem – are vertical farms the answer?

Globally, we have a tree-planting problem. As the climate and nature crises escalate, we need to plant billions of trees to remove carbon dioxide from the atmosphere and revive essential ecosystems.

In the UK alone, scientists are warning of the catastrophic collapse of forests within 50 years if we don’t take urgent action.

Alarmingly, we are way off-track when it comes to meeting our tree-planting ambitions. Although the UK Government aims to plant 30,000 hectares of trees annually from 2025 onwards, the latest figures show that it is falling extremely short. Last year, tree planting rates in the UK fell to their lowest levels for five years. Just under 13,000 hectares of trees were created into the 12 months leading up to March 2023 – not much more than a third of the Government’s annual goal from 2025 onwards.

To close the tree planting gap, we need to face three key barriers. First, we have a shortage of seeds. Seed collection is a small-scale industry and climate change is making it harder. Years of drought can halt a tree’s energy-intensive seed production. Warmer weather causes an increase in the bugs that eat up surviving seeds, while forest fires reduce the number of trees from which to collect seeds.

Secondly, the available seeds are not always the right ones. For example, oak seedlings imported into the UK from Spain are not suitable for our climate. Consequently, they tend to have low germination rates or their saplings die in polytunnels or when they are transplanted to their final site.

Finally, the ongoing soil crisis means that the soil in which saplings are planted is often not fertile enough. Healthy soil serves as the foundation for woodlands, supporting not just the trees but also the fungi and microorganisms they need to thrive.

Considering this trio of challenges, it’s almost impossible to see how we can accelerate tree planting to the necessary levels if we carry on as we are. We need to come at the problem differently. But we don’t have the time or the budget for years of research and development to devise brand new technology. What we need to do is make use of existing tech.

Innovation approach

As climate tech innovators, we at A Healthier Earth are all about applying pre-existing solutions creatively. For businesses like ours – that want to deliver impactful and scalable climate solutions within urgent timeframes – it makes sense to use technologies that are ready today but not yet being widely used to solve key problems.

Our ForestFactoryTM concept, which we are working on in partnership with Blenheim Estate in Oxfordshire, is a great example of how innovation can take the form of a new application of existing tech. As part of the project, we are trialling a solution that emulates forward-thinking fruit and vegetable farmers by growing young trees vertically, in stacked layers.

The trial will act as a proof of concept to showcase the application of vertical farming to traditional forestry. Vertical farms will enable us to produce the necessary volume of robust tree saplings from limited quantities of seeds, thanks to enhanced germination rates. The project demonstrates that, if the technology were deployed at scale, we could dramatically enhance the rate of global reforestation.

Our vertical farm is a highly controlled environment where layers of saplings are cultivated under LED lights using a hydroponic watering system. Monitored and operated by smart software solutions, we can mimic the conditions of the environment in which the young trees will be planted. We can simulate droughts, floods and anything in between – giving the saplings right characteristics to survive in our changing environment.

To complement our vertical farming technologies, we are scaling up traditional propagation techniques and deploying them at scale. By using the ancient woodland on Blenheim Estate, we can source the seeds and cuttings needed to grow large volumes of healthy saplings of a wide variety of species.

We’re then also looking at further enhancing the survivability of our saplings by addressing soil quality issues, using a biochar-based soil amendment to enrich the soils we plant in. This not only improves the soil’s fertility and water retention capacity, but also helps capture and store carbon.

A defining aspect of our approach with the ForestFactoryTM project is the use of existing technologies that have already been proven at a commercial scale. By reapplying them in a lesser-explored application, we reduce risk and increase the speed at which projects can be developed and rolled out.

Our new approach to reforestation underlines that innovation in climate tech isn’t just about new inventions. We don’t always need to reinvent the wheel. We can rethink or reapply solutions we already know work elsewhere to drive even greater impacts in different areas. In fact, in the short time we have left, this kind of innovation is central to scaling up action on the interlinked climate and biodiversity crises.

We need to get creative in our problem-solving, which involves being more imaginative about our use of existing tech. In practice, that can look like growing baby trees on shelves.

Alastair Collier is the chief R&D officer at A Healthier Earth

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