Sunday, June 24, 2018

Carbon Capture: Reforestation

Pre-industrialization, forests covered approximately 5.9 billion hectares across the planet. Today that figure is 4 billion hectares, and still dropping. The deforestation has reduced the ability of the terrestrial plants to sink carbon in their yearly growth.

The basic idea in reforestation is straightforward: plant trees and other long-lasting plants in order to take up and store carbon from the atmosphere. Development of mechanisms to plant trees in large enough scale and short enough time frame to be useful in ameliorating climate change is the difficult part. This requires automation, most obviously by use of flying drones.

Biocarbon Engineering and Droneseed are two firms building technologies for rapid planting of trees. They use largish drones loaded with seed pods. The drones do require pilots, as most jurisdictions now require licensed pilots for dones, but where possible the drones are set to fly in a formation to allow a single pilot to control many at a time.

The cost efficiency of this automated seeding method is not clear from publicly available information. Each reseeding project is a unique bid, and the bids are mostly not made public. Estimates of the cost of manual planting average $4940 per hectare using manual methods. Rough estimates of the cost of a Biocarbon Engineering project to reseed Mangrove trees in Myanmar is about half of what a manual effort would be.

Companies in this technology space

  • Propagate Ventures works with farmers and landowners to implement regenerative agriculture, restoring the land while keeping it productive.

  • Dendra Systems (formerly Biocarbon Engineering) builds drones which fly in swarms, numerous drones with a single pilot, and utilizes seed pods loaded with nutrients fired from the drones toward the ground. A good percentage of the seed pods will embed into the ground, and the outer packaging will rapidly biodegrade and allow the seed to germinate.

  • Droneseed also builds drones to plant trees, though fewer details are available.


musings on plants

In real deployments the type of plant life seeded will be chosen to fit the local environment by the client, such as the choice of Mangrove trees in Myanmar. If we were only concerned with the rapidity of carbon uptake, and did not care about invasive species, I think there are two species of plants we would focus on:

  • Paulownia trees which grow extremely rapidly, up to 20 feet in one year. These are native to China, and an invasive species elsewhere.
  • Hemp: "Industrial hemp has been scientifically proven to absorb more CO2 per hectare than any forest or commercial crop and is therefore the ideal carbonsink." (source). I find it amusing that hemp may be crucial in saving humanity after all.