In the second part of a two-part piece, island-based campaigner C.A.(Tony) Brown looks at the potential impact of some geoengineering ‘solutions’ to climate change
In a previous column on geoengineering, I touched on some of the methods being researched which either ‘suck’ CO2 from the atmosphere, or regulate sunlight. Here they are, in more detail.
One key method is the extracting of CO2 direct from the air by blowing air across water, and chemical-covered surfaces, in order to generate carbonate solids, from which CO2 is extracted by heating.
This would entail the following:
– extracting just 50 parts per million (ppm) of CO2 from the atmosphere would require 1,300 industrial facilities around the world, each consisting of an array of five machines 10 metres high and 1km long – attached to a CO2 extraction chemical plant, and another entire infrastructure to transport and bury the resulting waste.
– the materials and energy resources needed for building would be enormous (as it would, in fact, be for many geoengineering projects), and the sites would take a whole century to build at the rate of 13 a year.
Cold brightening, on the other hand, would entail the deployment of up to 1,500 unmanned, satellite-controlled vessels fitted with 28 billion millionth-of-a-metre nozzles, all pumping sub-micron-sized drops of seawater into the air so as to promote condensation in stratocumulus clouds.
The larger number of smaller droplets would enable the reflection of enough extra sunlight to offset, in theory, the warming effects of a doubling of CO2 concentrations.
But there are, again, drawbacks.
These include the disturbance of ocean circulation patterns, and unpredictable interference with climate systems, with potentially devastating effects.
Stratospheric aerosol spraying would entail the injection of 5 million tonnes of particles into the atmosphere by several thousand jet fighters, totalling a million 4-hour flights per year, to facilitate the blocking of 2 per cent of incoming radiation, and this would – again in theory – offset the warming effects of a doubling of CO2 emissions.
Five million tonnes is a tenth of the amount of sulphur pollution which currently arises from fuel combustion and industrial processes, but due to its altitude it would stay in the atmosphere for 50 times longer than it would if it were dispersed in the lower atmosphere.
It’s worth mentioning here that the 50 tonnes of sulphur we already have in lower atmospheric pollution have been so effective in offsetting global warming, that without it, and on top of the 0.8 degrees Centigrade of warming we’ve experienced to date, global mean temperatures would be warmer by something between an extra 1.1 and 2 degrees Centigrade!
In the event that China, India and other countries decide to follow the example of the West and introduce air pollution legislation, the scrubbing-out of sulphur, and so on, there could (counter-intuitively) in fact be a sudden rise in temperatures with many ecosystems and species unable to cope.
Sulphur aerosols stay in the atmosphere for a matter of weeks, but a typical CO2 molecule can remain aloft for more than a century.
Stratospheric aerosol spraying could also have the potential to alter rainfall patterns, causing devastating drought conditions in parts of Africa, South America and Asia.
In fact, a team at the University of Reading has studied this issue and deduced that a reduction in tropical rainfall of a massive 30 per cent is possible.
On top of this, there could also be significant damage to the ozone layer.
Nevertheless, despite all the drawbacks relating to geoengineering methods, various patents have been taken out by a range of companies eager to cash in on the belief that the world will be prepared to pay handsomely in order to prevent a perceived ‘climate catastrophe’.
Exxon Mobil, a company replete with long-term global warming deniers, seems now to have accepted global warming’s reality; that’s the only possible conclusion one can draw, surely, when it has funded a report concluding that sulphur aerosol spraying would be a cheaper response to warming than would phasing out fossil fuels.
Its CEO has, rather memorably, described climate change as an ‘engineering problem’, with ‘engineering solutions’.
In other words, perhaps, make money from wrecking the climate – then make more money attempting to fix it!