Geoengineering the future: Journal Club with Magdalena Matysek

The last Journal Club session was led by Grantham Scholar Magdalena Matysek, who introduced our first year PhD students to some of the debates surrounding geoengineering.

This week’s paper

‘Review of geoengineering approaches to mitigating climate change’ by Z. Zhang, J. C. Moore, D. Huisingh and Y. Zhao

Magdalena Matysek

In this week’s Journal Club we talked about geoengineering. As the collective name for all techniques which manipulate ecosystem processes, geoengineering can be used to counter climate change. These methods can be broadly classified into land-, ocean- and space-based and include measures such as fertilisation of oceans with iron to boost CO2 uptake by plankton, production and burial of biochar and CO2 capture and storage from the air. The paper by Zhang et al. (2015), which we based our discussion around, notes that some geoengineering methods are highly controversial due to side effects and substantial costs.

During our discussion, most people were of the opinion that geoengineering’s ability to counter climate change would be limited, at least in the near future, due to the intensity, spatial distribution and timing of side effects that are difficult to predict. For instance, cloud seeding, which is aimed at increasing the reflection of sun rays back into space, can potentially amplify cloud formation and rainfall over certain areas and decrease them over others. But this, of course, carries risks for crop production and global food security.

The group agreed that out of the techniques listed in the paper, reforestation is the approach which is most likely to gain support from governments and the general public. There are several reasons for this. Firstly, governments and organisations are open to the idea, since it is something that is already being carried out in many parts of the world, for example, in Africa and in China. that the advantage of tree planting lies in the multitude of benefits it provides, such as economic gains from agroforestry and conservation of biodiversity. Moreover, governments are unlikely to invest in schemes that are still in the experimental stage, and where there is uncertainty around how efficiently they can counteract climate change and the nature of possible side effects. Reforestation is therefore a safe bet, with known results and a low risk of encountering unwanted outcomes.

Still, tree planting as a geoengineering method can be easily abused by ‘reforesting’ degraded lands and cleared forests with monocultures (plantations of a single tree species). Such actions can cause a great amount of damage to ecosystems and the way they function.

On a more philosophical note, another reason why reforestation resonates well with the public and our discussion group is perhaps because it somehow lessens the guilt we feel about forest clearing, which is happening worldwide and often on a mass scale. remarked that geoengineering is an approach that addresses the symptoms of climate change rather than the causes. Is advocating its use, then, sending the wrong signal to the public? “It does not matter how much greenhouse gases we emit by burning fossil fuels and draining wetlands, since there exist technologies which can fix the situation for us” – this may be the implicit message sent by advocating geoengineering.

It remains to be seen which geoengineering techniques will be pursued in the future and to what extent. Nevertheless, it is doubtful that those methods that are both costly and involve undesirable side effects will receive much attention.