Synthetic Biology Can Be a Key Tool in Mitigating the Causes of Global Warming

October 17, 2019 – Charles DeLisi, at the Department of Biomedical Engineering, Boston University, has recently published an article appearing in the open peer-reviewed journal, Biology Direct, in which he proposes that synthetic biology (SSB) be considered for its potential to mitigate climate change through carbon removal and sequestration.

DeLisi describes how difficult it is for Developing World countries seeking to improve their peoples’ lives by increasing energy capacity, to avoid using fossil fuels, particularly coal. And he notes how the Developed World is reluctant to end its dependence on natural gas, or implement policies with teeth aimed to regulate carbon emissions. As a result, he argues that meeting Paris climate targets globally because the above remains highly unlikely.

A number of industrial carbon sequestration projects have been built to-date, representing efforts to remove atmospheric carbon and permanently store it. They are expensive and time-consuming to engineer, and we would need thousands of them to be built to begin drawing down atmospheric CO2 in sufficient quantity to alter our current path to temperatures well above 2 Celsius by century end.

Because of this DeLisi believes that SSB involving genetically modifying plants, and in particular trees, to alter the natural carbon cycle could prove effective. He writes, “some 120 gigatons of carbon are removed from the atmosphere by terrestrial photosynthesis, and every year essentially the same amount is returned by plant and microbial respiration.” But with a small reduction in the return step he believes we could “substantially reduce atmospheric carbon.”

How could this be done?

1. Engineering plants to absorb more carbon.
2. Engineering soil microbes to convert the organic carbon created by engineered plants turning it into permanently sequestered carbonates.
3. Or modifying the pigment in a few tree species to make them more thermal reflective to increase the albedo effect, cooling the atmosphere.

DeLisi focuses in his article on the first point arguing that through the modification of a few tree species we could accomplish significant carbon emission reductions. An alteration of 10% of the planet’s trees re-engineered to absorb more carbon could drop the annual 5 Gigatons rate increase by 22% without using any other mitigation technologies or practices.

That’s why DeLisi believes that SSB should be given consideration as a valuable tool under the broad umbrella of negative emissions technologies, and that it would be a mistake to omit it from serious consideration.

Why use genetically modified trees?

Because trees are “the dominant engine of carbon turnover” in the natural world. The process of experimenting with altering the plant genome of specific species will not necessarily be an easy task. But if we begin now we can identify favourable plant genomes that can be engineered and introduced into species to improve permanent carbon uptake.

For those who fear genetically engineering plants because of concerns related to the food supply, and protest all genetically-modified organisms (GMO), this proposal to modify trees to reduce atmospheric carbon should prove less worrisome.

DeLisi points out that humanity has been wrestling with carbon emission controls for over three decades since general consensus emerged about global warming. Negative emissions technologies such as industrial-level carbon sequestration projects have proven extremely expensive, with industrial partners often backing away from implementing them because of cost. What DeLisi proposes would entail a fraction of the investment, and yield within a few decades a far more effective long-term atmospheric carbon control.