From: cleoabram
Researchers are exploring the use of genetic engineering to create “supertrees” capable of capturing more carbon dioxide, aiming to help slow climate change [00:00:35]. This ambitious project aims to enable humanity to regulate the atmosphere for the biosphere [00:01:23], raising significant questions about how much other species should be altered to achieve this [00:01:34].
How Genetically Engineered Trees Work
The genetic engineering process involves incorporating new genes from other plants to enhance photosynthesis [00:02:08]. A key target is the enzyme “rubisco,” which sometimes picks up oxygen instead of carbon dioxide, leading to “photorespiration” — a process that wastes energy and releases carbon dioxide [00:02:45]. By altering the expression of genes that control this process, efficiency can be improved [00:03:02].
A “gene gun” is used to coat gold particles with DNA fragments and shoot them into plant cells, incorporating new genes into the plant’s genome [00:03:07]. This method is favored for regulatory reasons because it doesn’t involve bacteria or introduce non-plant pest genes [00:03:34]. Early results indicate that some seedlings show enhanced photosynthesis and a higher rate of carbon assimilation [00:03:56].
Why Alter Trees Instead of Just Planting More?
One primary consideration is the scale of the problem. To account for anthropogenic human carbon emissions by planting only unaltered trees, approximately a trillion trees would be needed [00:04:50]. If genetically enhanced trees could reduce this number to around 500 billion, it would represent a significant reduction in the required planting effort [00:04:58]. A small change in an individual organism can magnify to a much larger impact when spread across many organisms [00:05:14].
Carbon Cycle Limitations and Benefits
The “fast” carbon cycle illustrates a challenge with tree planting: while trees take in carbon dioxide, much of it is released back into the atmosphere when leaves fall or the tree decomposes [00:05:42]. This contrasts with the “slow” carbon cycle, where carbon from ancient biomass is trapped underground in fossil fuels [00:06:13]. For trees to be effective in combating climate change, they need to help trap more carbon long-term [00:06:30]. Trees that trap more carbon could be a significant help if the carbon is then sequestered permanently [00:06:39].
Addressing Concerns About Invasive Species
A significant concern with planting genetically engineered trees in the wild is the potential for them to become invasive species [00:06:51]. Introducing a new species not naturally found in an environment can disrupt the delicate balance of other plants, microbes, and soil, potentially worsening the carbon problem [00:07:06].
To mitigate this, companies developing these trees emphasize working with native species. For instance, they are enhancing loblolly pine and longleaf pine, which are native to the Southeastern U.S [00:07:11]. The goal is not to plant a single genetically engineered species everywhere, but to inspire scientists globally to enhance photosynthesis in plants native to their specific environments [00:07:34]. Much of their research on photosynthetic efficiency is made public to encourage wider efforts in forest biotechnology for carbon removal [00:07:49].
Impact on Tree Growth and Size
While genetically engineered seedlings show more biomass accumulating more quickly, there is no evidence yet that the final adult size of these trees will be different [00:08:52]. They simply reach their mature size more quickly [00:09:03].
The Broader Vision: Planetary Regulation
The ultimate vision for developing these trees is to help humanity take on the unprecedented responsibility of deliberately and continuously regulating the atmosphere of the planet for all living things [00:01:15]. This responsibility arises from humans destabilizing the atmosphere, much like algae did when they first evolved and produced oxygen, causing a mass extinction [00:10:03]. This involves a shift towards humanity acting as the species that regulates the atmosphere’s composition for the biosphere [00:10:20].
“In the future, it is going to be necessary for humans to be the species that regulates the composition of the atmosphere for the biosphere.” [00:10:20]