The recent announcement by climate watchers that carbon dioxide level in the atmosphere has crossed a psychologically significant barrier of 400 parts per million raised all the intended alarm bells world over. In a field which has been continually consuming a lot of public attention, and where the public are fed bits and pieces of information, this was one more bite meant to prod stakeholders into action.
Taking centre stage in this context is geoengineering, which, after mitigation and adaptation, is the third strategy to evolve in the struggle to counter global warming. Govindswamy Bala, associate professor, Centre for Atmospheric and Oceanic Science, Indian Institute of Science (IISc), Bangalore, says geoengineering is, “any intentional planetary scale technique to counteract the effects of climate change induced by long-lived greenhouse gases”. In India, this is still at a nascent stage. According to him, the potential for this stream is small in India, “because we do not have complete knowledge of the risks and side effects. Further, geoengineering cuts across national boundaries and hence it is a global commons problem. Hence, we will need international — legal and governance — frameworks. Given the track record of global negotiations on reducing greenhouse gas emissions, the chances of reaching an international agreement on geoengineering are remote.” To understand geoengineering better, one should look at mitigation and adaptation as well.
Global warming due to increased greenhouse gas emissions since the Industrial Revolution is a major global concern. The most vigorously pursued remedy for the same is Mitigation — ways of reducing emission of greenhouse gases. This method, which advocates abstinence, and hence less consumption and definitely for a period of low economic activity on the part of all nations, has pitted developing nations against the developed world. Upcoming economies see the move as one which makes them pay today and compromise their future to pay for the sins committed by developed nations in the past. Hence, the several rounds of bargaining and for most part no result.
The efforts of Mitigation are far reaching. It has lead to the search for non-fossil fuels-based energy sources (solar, wind, water, nuclear), the advent of fuel-efficient cars and many strategies for living with reduced greenhouse gas emissions. However, these efforts are costly especially for developing nations and there are no quick ways by which countries like India or China can shift out of thermal power to other types without sacrificing the economic rates of growth achieved by them after a great struggle.
Even for the developed world, which is going through a long phase of slow to negative economic growth, the cost of addressing global warming concerns are staggering. One estimate puts the global cost at $45 trillion, roughly four times the GDP of USA!
One inherent problem with Mitigation is that everyone has to comply, or the effort is a failure. Given the levels of mistrust between nations, it is easy to imagine why progress has been slow.
The other aspect is that costs and benefits are not localised. A person living in the highlands of Scotland, who might well enjoy a few degrees rise in temperature, is asked to bear the cost of saving Maldives. It is easy to imagine how much enthusiasm the Scots would have to suffer additional costs for such a cause. If one thought these are the biggest shortcomings of Mitigation, they are wrong. Mitigation merely controls emissions in the future. It does nothing about the high levels of carbon dioxide in the atmosphere. If the world is getting hotter by the year because of what happened since the Industrial revolution, it would continue to get hotter as the higher levels of carbon dioxide, which caused the increase in temperatures, would still remain in the atmosphere! Mitigation strategy, when successful, merely reduces the rate of increase.
The strategy of Adaptation is one where mankind accepts global warming as inevitable and prepares for the effects — higher temperatures, higher sea levels, severe storms, cycles of floods and droughts, etc. These would include initiatives like building dykes to protect coastal cities and towns, better disaster management facilities and so on. In this approach, nothing needs to be done now or in great haste. The schemes are such that the cost and benefit are localised — New York city builds a dyke at its cost to protect itself!
The third approach is geoengineering, which is a deliberate and large-scale intervention in the Earth’s climatic system with the aim of reducing global warming. Very broadly, geoengineering embodies two approaches — one towards removing carbon dioxide from the atmosphere, and the second called solar radiation management (SRM), which deploys measures to reduce the amount of solar radiation that reaches the surface of the Earth.
One of the strategies for carbon dioxide removal is afforestation — plant more trees to reduce levels of carbon dioxide in the atmosphere. However, some research has shown that trees planted in the tropics only result in net cooling. Trees planted in temperate and subpolar regions reduce the reflectivity of the surface and hence result in warming rather than cooling. These findings are being debated but the fact that trees increase the absorption of heat — by being darker — is an accepted fact.
One other geoengineering initiative for carbon dioxide removal is iron fertilisation. By introducing iron to the upper ocean, it is claimed that phytoplankton growth would be simulated and this increased activity would absorb more atmospheric carbon dioxide. Plants need iron for photosynthesis. However, iron is highly insoluble in sea water and there is often a nutrient deficit in phytoplankton growth. Geoengineering proponents believe that large phytoplankton blooms can be created by supplying iron to iron-deficient ocean waters. In India, climate modelling of geoengineerng to assess its effectiveness, side effects and risks is performed at IISc. “A few years ago, National Institute of Oceanography, Goa, in collaboration with German scientists, conducted field experiments in the ocean to understand the effectiveness of ocean iron fertilisation,” reminds Prof Bala.
The other strategy for cooling is the “cool roof”. These are measures to increase the reflectivity of the Earth’s surface. One small example is using a reflective paint on the roof of buildings, which reflect the heat rather than absorb it. The same can be used on the roofs of cars to reduce the load of air-conditioners on engines and hence lower fuel consumption. There are also ways by which reflectivity of large surfaces are sought to be increased.
SRM is a tool that can be deployed at the surface level or in lower or upper atmosphere. The approach is to reduce solar radiation reaching the Earth or reflect it away. Methods suggested include marine cloud brightening and stratospheric sulphur aerosols. These measures are theoretically fast and can reduce the global average temperature quickly. They are also relatively cheap options.
One estimate by scientists, Lenton and Vaughan, suggest that these techniques can reverse the warming effect of a doubling in the carbon dioxide levels in the atmosphere. “Geoengineering methods that alter solar radiation appropriately can bring the climate back to pre-industrial period within five years. Climate modelling studies do indicate that the mean climate of geoengineered world could be closer to the climate of the pre-industrial period. However, regional and local climate in a geoengineered world might be vastly different from the base climate. Further, as I said earlier, there are known and unknown side effects and risks which need to be carefully assessed,” cautions Prof Bala.
The main attraction of geoengineering systems is that if effective, they don’t merely slow down the rate of change – they perform damage control. Further, they are locally deployable with global benefit. The cost of the initiatives are also highly manageable.
The cost of some of the initiatives are so low that they can be deployed quite effectively by any one of the developed or developing nations. They can even be deployed by rich individuals, since the cost would be a few hundred million dollars.
Local deployability implies that any country can start Stratopheric Particle Injection for Climate Engineering, which would benefit the entire globe. The same holds true for initiatives like iron fertilisation.
In a report issued in 2009, The Royal Society of UK, adjudged that afforestation and stratospheric aerosols as those having the highest effectiveness and affordability. Despite these advantages and benefits the pace at which these ideas and initiatives have been tried is dismally slow. In fact, most of the concepts are yet to be tried even at field level. The only chance to observe the effect of geoengineering initiatives happened in 1991 when Mt Pinatubo in the Philippines erupted spewing 20 million tonnes of sulphur dioxide into the upper atmosphere, resulting in observable global cooling for years. This natural lesson apart, all the initiatives are within the realm of computer modelling. Sulphur aerosols, however, can deplete the ozone layer but substitutes for sulphur are available.
There was one other experiment by Russ George, founder president of Planktos Inc, who conducted an iron fertilisation experiment in the Pacific Ocean and reported an increased algae growth in tens of thousands of square kilometres. His action was, however, criticised and it has been pointed out that he broke several resolutions of various conventions — US and global.
There are many objections to geoengineering, mostly from ethical and moral stand points. The arguments range from the possibility that geoengineering solutions might divert attention away from Mitigation to the philosophical views that such experiments cannot be undertaken without consent of all. “I think it is a bad idea. We have already created a huge global crisis by tinkering with nature through large-scale deforestation and fossil fuel emissions. In the case of deforestation, we have been tinkering with nature in the last few thousand years by removing forests and creating farm lands on a global scale leading to huge environmental damage. In the case of fossil fuel emission, we have been releasing greenhouse gases in the last 150 years, which has led to global warming,” says Prof Bala. “Both of these actions, deforestation and fossil fuel emissions, are in a way geoengineering experiments performed by humanity on the Earth but without intention. To counteract the bad effects of these unintentional geoengineering actions, we are now trying intentional geoengineering actions. It is like trying to cure a sick person using medicine. In the case of climate change, the planet would be the sick person and geoengineering, the medicine. If we believe prevention is better than cure, then we should start reducing our CO2 emissions, which is the root cause for the current climate change.” The practical view that is emerging is that geoengineering is a very useful tool that can be deployed in the near term to give efforts of Mitigation sufficient time to bear fruit.
There are calls for controlled field experimentation, but it is very nebulous as to who should control it and in what manner. Given this scenario, even academics are reluctant to venture into the next stage of field experiments with geoengineering techniques.
Calling for a framework within which experimentation could start and speaking about the dangers of not having such a framework, noted climate scientist Lemonick went so far as to express a concern that in the absence of such a framework countries like India and China might unilaterally commence some initiative! Given that the status of geoengineering thinking in India is still at a nascent stage, he need not have concerns about India at least of jumping the gun and starting the race early!
As Ken Caldeira of Stanford University observed, the greater worry is that useful experiments are not happening. It is today a case of everybody, anybody, somebody and nobody. Everyone knows the experiments are necessary and that somebody should do it. Anybody could do it but nobody is.