To absorb CO2, and although the assertion is sometimes disputed, we have so far not found anything better than trees. According to a study by ETH-Zürich in Switzerland, planting 1,000 billion trees would reduce the level of carbon dioxide in the atmosphere by 25% over the next two decades.
But where to plant all these trees, which represent the equivalent of the surface of the United States? Between the necessary increase in agricultural land to meet future food needs and rampant urbanization, there is a risk that space will be lacking. So, to capture more CO2, the startup Living Carbon aims to create supertrees with improved photosynthesis. You should know that natural photosynthesis is a process that does not shine by its efficiency: for most so-called C3 plants (cassava, rice, soybeans, etc.), barely 4.6% of the energy received is transformed into biomass.
Many teams are therefore working around the world to manipulate the photosynthesis process to increase the capacity of plants to convert CO2. In 2019, a team from the University of Illinois managed to increase the yield of tobacco plants by 40%. While most of the research focuses on the efficiency of agricultural yields, Living Carbon plans to apply this technique to trees.
“Imagine if instead of planting 1,000 billion trees, you only need to plant 500 billion? This frees up space for many other uses,”says Maddie Hall, founder, and director of the start-up.
The company does not disclose any details for the moment on the technique used to produce its supertrees, but if it were similar to the method that applies to tobacco, it would result in taller trees that grow faster, therefore more absorption of carbon dioxide. Living Carbon is also developing a second innovation consisting in reducing the amount of carbon released by the tree when it decomposes by allowing it to capture the copper and nickel in the soil, which destroy the fungi (the latter are responsible for the decomposition wood).
All of this is still at the research stage. Moreover, although it can be assumed that genetically modified trees will encounter less resistance than those faced by edible plants, Living Carbon still risks encountering regulatory obstacles. The FSC label, issued to responsibly managed forests, for example, does not authorize GM trees. The poor poplar lignin is supposed to facilitate the production of paper and has never been successful.
But for Steve Strauss, a plant biotechnology professor who advises the start-up, the climate crisis will inevitably lead us to rethink our attitude towards genetic engineering technologies, if only because the trees will have to grow in a more environmentally friendly atmosphere, drier and warmer. A new dilemma among environmentalists.
Writer: Imaaz Nadeem