How genetic engineering can help tackle the climate crisis

A rice paddy mid-harvest, Laos (2017). Genetic engineering may help improve rice yields in a warmer climate. Basile Morin, CC BY-SA 4.0, via Wikimedia Commons


The products of genetic engineering (GE) have been called many things – “Frankenfoods”, “seeds for corporate greed”, and “weapons of mass destruction” to name a few. But rarely do we see them heralded as the answer to the climate crisis.

In fact, advertisers will often market products as “natural” and “organic”, using their GMO-free status in a bid to make them seem more planet-friendly. The public’s perception of GE remains sceptical, and environmental organisations like Greenpeace still argue against the technology on their websites.

People’s concerns about their communities must be respected, and the concept of seed sovereignty raises valid questions about genetic diversity and the rights of farmers versus corporations. However, it is also true that a long history of misinformation, poor science communication, and even conspiracy has caused confusion around this topic.

The reality is rather simple: GE is an addition to the toolbox that humans have already used to dramatically alter species to suit our needs, from beagles to bananas. Like any tool, it has the potential to be used for harm, but it certainly has no inbuilt factor that makes it “evil” and should be assessed on a case-by-case basis to ensure its safety.

We can already see examples of GE technology helping both people and the planet, so what hope could it offer as we face an accelerating climate crisis? Could it help us to limit its speed (mitigation), as well as to cope with the inevitable consequences of increased emissions (adaptation)?

Carbon-guzzling crops

As the global population increases and climate change puts more and more strain on existing food systems, there is a rising risk that crop demand will overtake supply.

The recent blockage of grain exports from Ukraine, the world’s “breadbasket”, has been a sharp reminder of how vulnerable food security can be. In many parts of the world, already suffering from altered weather systems, no reminders are needed.

Commonly, when people talk about solutions to this problem, they separate out the idea of ‘agro-ecology’, the sustainable integration of ecology with agriculture, from biotechnological methods. This assumed dichotomy is false. We will likely need an integrated combination of approaches to combat the scale of this issue, recognising the wide variety of factors that can affect crop yields.

Genetically engineered plants, such as drought and flood resistant crops, could soon be necessary to minimise farmers’ losses and thus keep people alive. Specific attempts to improve the resilience of food crops in the face of climate change include engineering super short corn to withstand stronger winds, and heat resistant rapeseed pods which won’t shatter before they are harvested.

Another avenue that scientists are particularly excited about is the manipulation of photosynthesis itself. For example, the C4 Rice Project is focussed on improving rice crops by incorporating elements from the C4-type pathway—a type of photosynthesis already used by some important crops such as maize and sugarcane.

The pathway is more efficient than other photosynthetic processes as it uses 2 different cell types to concentrate CO2 around the crucial carbon-fixing enzyme, Rubisco. This prevents photorespiration, a costly process that happens when Rubisco holds onto oxygen instead of CO2, resulting in toxic waste products that must be recycled. Therefore, crops engineered to use the pathway are expected to be high-yielding.

What’s more, C4 plants have a particular advantage under hotter and drier conditions. This is due to an increase in water use efficiency as they can afford to keep their stomata (the leaf pores that regulate both CO2 uptake and water loss) more tightly closed than C3 plants. Therefore, the project claims that it will also grant rice “greater resilience to abiotic [physical] stresses associated with climate change”, boosting realised yields. 

Some scientists are considering something even more revolutionary by combining higher fixation rates with better plant roots to store more carbon underground. This idea of enhanced biological carbon storage, a nature-based solution taken to the max, could be more successful than other methods currently being developed by physical engineers.

The Salk Institute for Biological Studies is one of the groups researching this proposal. It is spearheaded by Professor Joanne Chory, an American geneticist, who explains that ‘we have to find a way to take CO2 out of the atmosphere and I think plants are the only way to do that affordably’. The CO2 Removal on a Planetary Scale (CRoPS) project, which Chory founded, wants to alter crop roots so they can store carbon deeper in the soil. It focuses on suberin, a material that makes up cork and is very resistant to degradation, as the key to making this storage long-term.

Cheese without the cow

Although plants remain one of the most iconic GE applications, its potential uses stretch far broader.

Despite the recent rise of veganism in some Western countries, the world is expected to consume more and more dairy products as nations grow and develop. Livestock farming contributes to climate change, via both land use change and the methane produced by cows as they digest grass. Whilst complex to measure due to variation in farming practices, a 2010 report by the FAO concluded that the dairy sector is responsible for around 4% of global emissions.

Plant-based alternatives are a growing market, projected to grow, on average, by 12.5% annually between now and 2030 though they cannot yet replicate their dairy counterparts in taste and texture. Vegan cheese, commonly made from coconut oil, is known to be a particular challenge. To address this, some biotech start-ups are trying a different approach—genetically engineered yeast, programmed to make the exact same proteins found in cow’s milk.

The first group to act on this idea was the Real Vegan Cheese project, based at Counter Culture Labs in California. In 2014, the team won an iGEM prize for the best community lab project and built their movement from there, as grass-root pioneers of what has grown into ‘the fermentation-enabled dairy industry.’ To produce milk proteins, yeast cells are given synthetic DNA containing the appropriate instructions and put in large bioreactors, where they act like “factories”.

At the end of the process, the mixture is purified and the final product contains no yeast cells. This means it can be classed as GMO-free, which affects how easily it can be regulated.  In theory, the milk has the same nutritional value, taste, and texture as regular dairy milk and could even be healthier if cholesterol is not added. It can then be processed and packaged into any other dairy product.

Real Vegan Cheese is not the only group working on this. Many start-ups with various dairy-related puns have popped up over subsequent years.  For example, Remilk, an Israeli based food company, was only set up in 2019 and yet is already valued at around $500 million. Recently, Remilk has claimed to be working on feeding their yeast with agricultural waste to make the process even more climate-conscious and announced its plans to open the world’s largest fermentation facility in Denmark.

As these alternative options become more readily available, we might see a mainstream shift away from animal agriculture, allowing us to keep eating foods we enjoy without such a high carbon cost. From an adaptation perspective, alternatives will also be needed if heat stress makes cattle-farming infeasible.  

Colourful corals

Away from food altogether, others are wondering if GE technology could help address the ecological issues arising from climate change. Corals, the foundation of reefs across the world, are especially vulnerable.

Increased water temperatures cause coral species to expel the vibrant algae that live inside their cells, which provide them with sugar in exchange for shelter. It is then only a matter of time before a coral dies of starvation, in a process known as “coral bleaching” due to the associated loss of colour.

A quarter of all marine life relies on coral reefs. They also provide crucial services for humans, acting as nurseries for the fish we eat, providing potential medicines, and protecting coastlines. As severe annual bleaching events are projected to occur in 99% of the world’s reefs within this century, what hope is there that they can be saved? Current restoration methods involve people manually transplanting coral fragments grown in special nurseries onto reef sites, but some worry this will not go far enough.

A partially bleached coral reef.
A partially bleached coral reef. Genetically engineered coral may better withstand warmer temperatures. Matt Kieffer from London, United Kingdom, CC BY-SA 2.0, via Wikimedia Commons

GE is already being used for research into the coral bleaching process. The CRISPR-Cas system, a type of “molecular scissors” that allows very precise gene editing, is able to “knock out” specific genes. By deactivating them in this way, scientists are able work out their effect.

The first example of using CRISPR in this way was published in 2020, by a Stanford team led by Philip Cleves. One protein identified as important in determining whether corals will survive higher temperatures was Heat Shock Factor 1 (HSF1), which can turn many other genes on and off. Coral larvae without a functioning HSF1 quickly died when their tank reached 34 °C, whereas unedited corals did not.

By understanding coral biology, we could better predict and possibly control what will happen on reefs in the future. We might even be able to use GE technology to breed corals that are extra resilient to high temperatures, in a form of “assisted evolution.” However, this is a far more controversial idea, which would need to pass the high bar of regulatory approval and public acceptance before it is implemented.

Regardless, the idea is tangible and worth thinking about, as it could become more likely once the colossal impact of lost reefs is felt. Australia’s Great Barrier Reef is particularly at risk of extinction, with over 80% impacted by severe bleaching since 2016. Such urgency could explain why a 2021 study exploring public acceptability of GE corals, found that Australians are not averse to the development of a synthetic biology solution for restoring the reef. Additionally, regulations around biotechnology can be updated, as evidenced by the recent relaxation of rules around gene editing in the UK.

Caution

All these applications of genetic engineering are exciting and hold a lot of promise for both mitigating emissions and adapting to the consequences of climate change. With the help of this tool, we might be able to revolutionise our food systems, or even influence the evolution of struggling species.

However, it is important to emphasise that GE is not the definitive answer to the climate crisis, as no technology can be counted on as a “silver bullet” solution to such a multi-faceted problem. Funding research into these ideas is vital and can provide important hope, but we must recognise that there is a long journey between the lab and the field, shelf, or ocean. Ultimately, we cannot rely entirely on any technology—GE included—to save us from other necessary changes we must make to break our dependence on fossil fuels.