Thinking outside the crops - bio-geoengineering as a way to combat climate change

So far I've looked at the use of GM in relation to enhancing food security in the face of climate change. However, GM may also have a role to play in geoengineering, which is another strategy being considered to mitigate the impacts of climate change. 

This post will look at the potential uses of genetic modification in geoengineering projects.

What is geoengineering?

Geoengineering is where humans disrupt natural processes to mitigate the impacts of climate change, this may be through Solar Radiation Management (SRM) or Carbon Dioxide Removal (CDR). You can read more about some of the techniques here. They tend to operate on a large scale, as carbon dioxide and solar radiation are global-scale issues.  Think on a huge scale, reflectors of solar radiation in space, adding nutrients to the ocean and mixing dissolved, alkaline rocks into the sea are all possibilities which have been put forward.

This paper by Pidgeon et al, 2012, explores some of the early attitudes towards geoengineering, and reflected on how important public perceptions are in terms of the success of wider projects. The study found that the baseline level of knowledge in 2012 concerning geoengineering was very low, which may influence the negative perceptions towards its use. It was found that 'carbon dioxide removal approaches were preferred to solar radiation management' (p1) and that those who knew more about the impacts of climate change and were more concerned about it were more supportive of geoengineering plans.

How might genetic modification be used in geoengineering?

Using genetic modification methods to enhance aspects of a large scale climate change intervention is known as bio-geoengineering. 


Enhancing the albedo of leaves 

In this situation, the idea is to make use of existing agricultural practices, but to grow crops with leaves which have a higher albedo and therefore reflect more sunlight. Ridgwell et al, 2009, calculated that surface temperatures should be able to be reduced by around 1 degree Celsius in Central North America/Eurasia in the summer season. 

However, other studies have looked at the extent to which these cooling benefits apply and found that they tend to be limited to the local region where it is being implemented, and the season (Irvine et al, 2011). It has also been noted that the background climate will have a lot to do with the success of bio-geoengineering in that region (Singarayer et al, 2009).

Source. Imagine if this was able to reflect solar radiation.

Changing crop albedo is deemed to be a climate change mitigation strategy which could be suitable for developing countries, as it can be set up on a relatively small scale and budget in comparison to other geoengineering strategies (Nogues and Azcon-Bieto, 2013).

So perhaps the role of GM could extend further than enhancing food security, it seems that there may be potential for genetically modified crops to help cool the surface temperatures which have been rising as a result of climate change, albeit on a more local scale.