As Michael Oppenheimer, professor of geosciences and international affairs At Princeton University, has declared, ‘we’re all in big trouble’. Some would say that civilization is under threat and may not survive. Many of the world's major coastal cities, including London, will be flooded and have to be abandoned.
Surely we will be saved by the international agreement to reduce greenhouse gas emissions. Hardly; it is too little and too late. Greenhouse gas emissions continue to increase, in fact they are accelerating. They have increased by about 80 per cent since 1970 and the amount of carbon dioxide (CO2), the main driver of global warming, has risen from the pre-industrial level of 280 parts-per-million to the present 415. It is still rising, mainly due to emissions from the USA, China and India, countries that value their industrial output and see no reason to commit economic suicide.
It is important to realize that global warming relies on two interacting factors: heat from the sun from insolation and increasing emissions of greenhouse gases. So if we cannot reduce emissions, perhaps we can reduce insolation. This is what geoengineers propose. They argue that, although technology has got us into this mess it can get us out of it. They have proposed various ways to reduce insolation, ranging from painting the world white to deploying a space mirror. Of course none of these measures, some of them very expensive, would reduce greenhouse gas emissions, but they could give us more time to deal with that problem. Faced with the collapse of civilization, there is an urgent need to stop the warming, whatever else we do.
We do not need to look far for a practical geoengineering method. Stephen Salter, Emeritus Professor of Engineering Design at the University of Edinburgh has a proposal to brighten ocean clouds so that the world's albedo is increased (‘albedo’ is the measure of the diffuse reflection of solar radiation out of the total solar radiation received by an astronomical body). This would involve about 300 or so specially-designed unmanned ships equipped to spray very small water droplets, which then brighten clouds (the smaller the water droplets, the brighter clouds become). Calculation shows that spraying over only 3.3 per cent of the Earth's surface, for example only in the North Atlantic, is enough to cool the planet by about 1 watt per square metre, dealing with about half the warming. Eventually this method could halt the increase in temperature and even lower it, reducing the dire effects that warming is already producing.
Prof Salter has worked on this scheme for 20 years and recently presented his idea to MSPs at Holyrood. At present he is funding his own research but he lacks the funds to develop the idea. Here is an opportunity for Scotland to lead the way and save the world. The scheme would generate many jobs in shipbuilding, an industry in need of investment.
However, there is much opposition to geoengineering techniques, alleging that they do nothing to address the root causes of climate change, with a high likelihood that rather than improving the climate they would make things worse—potentially in a catastrophic fashion. It is alleged that schemes like Salter’s come with high-stakes risks: entire regions could face drought. However, this opposition may be declining as the alternative becomes clearer. The risks of geoengineering changing weather patterns seems preferable to the risks of doing nothing. No amount of renewable energy schemes and recycling is going to stop global warming. A desperate situation demands a desperate remedy.