There is no clear roadmap agreed globally on how to resolve our existential crisis. But there is more or less an agreement that the concept of bioeconomy and sustainability should be ingrained in our financial models. Synthetic biology, a disruptive technology promising to make living systems easier to engineer, should be able to provide solutions in this direction. But can synthetic biology really mitigate climate change?
In a recent article, Charles DeLisi from Boston University makes a point that (plant) synthetic biology has an important role to play in climate change mitigation. If we take a look at the global carbon cycle (depicted in the image below) we can see that the majority of carbon is absorbed and emitted from terrestrial ecosystems. As consequence, accelerating carbon sequestration and reducing carbon respiration in bioengineered trees can reduce – or at least stabilize – atmospheric CO2 levels.
I agree with Professor DeLisi that increased carbon sequestration, probably by more and potentially engineered trees, can have a significant effect in the carbon cycle. I also see several other areas that synthetic biology may have a positive contribution to our carbon footprint.
Enhancing agricultural efficiency and crop yields can reduce the land needed to feed an ever-growing human population, and ensure better use of soil resources. A particularly impactful area of research is nitrogen fixation: providing crops with such ability will diminish the need for nitrogen fertilizers, produced when atmospheric nitrogen is converted into ammonia via the – energy-demanding – Haber process. In a recent study, Giesbrecht and Menge argue that giving trees nitrogen-fixing capabilities will have a positive effect on climate.
The field of biomaterials is another area of potential impact. Replacing chemical feedstock with bio-derived alternatives can reduce reliance on fossil fuel. The area of fashion and textiles is where synthetic biology can really make a difference. Replacing the current, environmentally damaging practices of the fashion industry can protect ecosystems, reduce carbon footprint, and prevent land use change.
The development and implementation of algal biotechnology might be a real game changer. Algae and cyanobacteria, growing in seawater and in areas where no agricultural production is possible, can produce biomass, pharmaceuticals, animal feedstock, nutrition supplements, and potentially biofuels out of practically thin air.
However, we should be realistic on what to expect from synthetic biology, especially since we need to act in a very short timeframe. Enhanced photosynthesis and increased carbon fixation is a field of extensive research, and despite some impressive recent progress, the implementation of such a technology and the generation of efficient carbon-sequestering trees might be more than a few years away. I also struggle to see a scenario where the plantation of bioengineered forests will have wide public acceptance. It should be noted though that synthetic biology research does not necessarily need the release of GM plants to have an effect. A technology that enables the better understanding of biology can guide traditional breeding techniques into producing plant lines with improved characteristics, albeit in a longer timeframe.
A second thing to keep in mind is that biotechnological applications are not always carbon neutral. Heterotrophic bacteria and fermentation processes need a carbon source and nutrients that need to derive from somewhere. Even algae, that can directly use CO2, may require energy to maintain the cultivation conditions steady (e.g. for temperature control).
A third, and maybe most important, factor is the financial cost. We may develop a fantastic synthetic biology application that diminishes the environmental footprint of a process; however, it will never be implemented if it’s not economically viable. If this application directly competes with the established process, the competitors could react by dropping prices, or even by challenging the need and validity of an environmentally friendlier procedure.
Synthetic biology can have varied indirect contributions in the climate change front. As a research tool, it can guide the development of novel applications, especially in the area of agriculture. As an educational tool, synthetic biology can pass the message that even complex industrial problems may have a biological solution. And it can foster a community under the banner of sustainability.
Despite popular belief, individual lifestyle choices have a minuscule effect on climate. Tackling the climate crisis will require change of environmental policy, brave reduction of carbon emission, and a shift in consumer behavior. Without these, no technology will appear as a deus ex machina at the very last moment to save humanity from itself. However, we are at a stage where every technological aid should be used. Synthetic biology and biotechnology will never be the solution to climate change. But they may become an essential part of the solution.
Kostas Vavitsas, PhD, is a Senior Research Associate at the University of Athens, Greece. He is also community editor for PLOS Synbio and steering committee member of EUSynBioS. Follow him on Twitter @konvavitsas