Is geo-engineering the answer to the potential ravages of climate change?
The year 2019 may come to be seen as an important year for climate change. Several high profile demonstrations raised awareness amongst the public on a critical issue and rightly placed a responsibility on politicians to ensure there is real progress towards the 2020 targets agreed in the Paris Climate Agreement. The media have taken the opportunity to help inform the public about the implications of rising global temperatures, the deteriorating state of the oceans, and the worrying rate of deforestation. The UK Government caught the mood and, once again, took a lead role by moving towards a legally binding ‘net-zero’ greenhouse gas emissions target for 2050. It will be interesting to see what new policies and measures are brought forward to help the UK meet this ambitious new target.
In another development in 2019, the University of Cambridge established the Centre For Climate Repairto explore radical solutions to climate change. The Centre will investigate potential of new approaches to help mitigate the problem using technologies that can be deployed on a large scale. For example, one idea is to refreeze the poles by ‘brightening’ the clouds above them using sea spray. Another idea is to ‘green’ the oceans so they can take up more carbon dioxide by ‘fertilising’ the sea with iron salts to promote growth of plankton.
There are some serious concerns with a potential ‘geo-engineering’ solution. For example, at the technical level this approach assumes that we understand the complexities associated with the environment and that we can predict the detailed outcomes from potential interventions; this is not true. And from a behavioural point of view the idea that there is a potential ‘cure’ for the climate change problem may ‘legitimise’ continued use of fossil fuels, weakening mitigating action and adaptation preparedness. This concern was expressed by James Lovelock, the world-renowned environmentalist, in his Memorial Lecture on receiving the John Collier Medal in 2006 titled Global Heating from an Engineer’s Viewpoint:
“When people become aware of the reality of global heating they will try to fix it with sunshades in space or by stratospheric particles that reflect sunlight away from the Earth. Technological fixes of this kind should not be unthinkingly condemned; they might buy us all some much needed time but more probably they would provide the excuse to continue business-as-usual.
It is instructive to consider ‘geo-engineering’ in the context of another major environmental crisis that was identified in the 1970s: the so-called ozone ‘hole’, an annual decrease in stratospheric ozone that occurred primarily in the spring over the Antarctic pole. Academic research suggested this was a man-made phenomenon involving, in the main, a group of chemicals, chlorofluorocarbons (CFCs), created in the late 1920s. CFCs were stable, non-toxic, non-flammable alternatives to ammonia, butane, and sulphur dioxide used in refrigeration and later in air conditioners and spray cans. To make matters worse, CFCs were also found to be greenhouse gases thousands of times more potent than carbon dioxide.
Following considerable research and in-situ measurements it was possible to explain the complex chemistry of CFCs inthe highly stable stratospheric environment above the Antarctic, and to confirm their role in the destruction of ozone. The international community reacted quickly and positively with the Montreal Protocol on Substances that Deplete the Ozone Layer, a landmark multilateral environmental agreement that proposed regulating the production and consumption of man-made ozone depleting substances.
The Montreal Protocol was formally adopted in late 1987 and was followed by regular meetings of the Parties to the Protocol in later years. The international community agreed that there would be gradual phase out of these chemicals to be replaced by alternatives that did not contribute to ozone depletion. It was also recognised at the time that ‘repairing’ the ozone layer would takes many decades and this has proved to be the case, as shown in the figure below.
There is however a cautionary tale associated with this environmental problem. At the height of the crisis academics were considering other options for repairing the ozone hole including the idea of geo-engineering. For example, in 1991 some academics published a paper in Science suggesting that, based on their modelling studies, 50,000 tonnes of ethane and propane could be released directly into the stratosphere to disrupt and neutralise the ozone depleting chemistry. The academics did recognise that there may be unforeseen side effects; for example, too little ethane and propane may actually enlarge the ozone hole.
The academics’ stated intention was to put potential large scale ‘solutions’ under scientific scrutiny, not unlike what is being proposed by the Centre for Climate Repair. To be fair, the academics involved at that time also recognised that such proposals faced significant legal and ethical questions. In particular, it was not clear who has the right to make decisions on potential interventions that have regional or global implications, and whose rights were being preserved. These questions must also be considered in the climate change debate today.
Climate change is a much more complex and global issue than the ‘ozone hole’ over the Antarctic.And it is important we continue to carry out research on the problem. But we are already conducting a global experiment by releasing greenhouse gases into our atmosphere and the question is do we want to embark on another experiment by potentially adopting geo-engineering ‘solutions’.To alleviate the impacts of climate change it is best to focus on eliminating the emission of carbon dioxide and other greenhouse gases as soon as possible rather than be seduced by the idea that it may be possible to ‘correct’ the problem through large-scale geo-engineering ‘solutions’ whose outcomes are far from certain.
The moral of this story is the old adage that prevention is better than a cure, and the way the international community addressed the Antarctic ozone ‘hole’ phenomenon shows the way.
Chris Anastasi - September 2019