At a time when the effects of climate change are starting to affect the livelihood of individuals around the world, climate policy has climbed up in the agenda of policy-makers. With countries around the world pledging to do the near-impossible – to limit warming to 2 degrees Celsius, the world would have to move rapidly toward 100% clean energy, thus producing zero net greenhouse gas emissions by 2060. To reach this objective, intensive mitigation efforts would have to be undertaken. Given that global climate change is a public good, supplying it by means of reducing emissions through mitigation efforts makes it vulnerable to free riding. Few countries are likely to participate in such an effort; hence it makes economic sense to give geoengineering a chance. The only challenge faced by geoengineering would not be free riding, but governance.
Geoengineering refers to the deliberate manipulation of Earth’s climate to tackle human-induced global warming. Two fundamental forces determine the Earth’s climate: the amount of solar radiation that strikes the Earth and the amount of this radiation trapped by the atmosphere. The latter effect is determined by the concentration of greenhouse gases, whereas the former depends on the solar cycle. The main approaches of geoengineering solutions are Solar Radiation Management (SRM) and Carbon Dioxide Removal (CDR). The latter deals with the root causes of climate change and involves reducing the amount of CO2 already in the atmosphere However, at this point in time this strategy is considered too expensive to be cost effective.
On the other hand, SRM does not necessarily reverse the climate change caused by the greenhouse gases, nor can it compensate for the CO2 driven climate change, but given the very slow pace of actions taken by the international community in mitigating the climate change, SRM could be a solution that could divert in the short-term the effects of global warming due to its cost-effectiveness compared to CDR. However, as greenhouse gas concentrations are not reduced by these methods, the application of any SRM method would carry with it the termination problem and would not address ocean acidification or other CO2 effects. Injection of sulphate aerosols into the stratosphere is the only area of SRM where experimental proof, provided by volcanic eruptions, has shown the magnitude of the reduction in global temperatures that can be expected.
Geoengineering, like other emerging areas of technology, requires flexible frameworks of governance and regulation, which can be adapted as new evidence and analysis comes out. Full deployment would require a long-term, uninterrupted commitment to continued injection at the scale of tens of kilograms of material per second injected quasi-continuously. A sudden interruption after a sustained deployment could result in rapid temperature increases over a period of a few years, causing potentially severe impacts on ecological systems. This approach could also lead to reduced rainfall and a reduction in the intensity of the global water- often referred to as the hydrological cycle, since the global water cycle is more sensitive to changes in solar radiation than to equivalent increases in CO2.
There appear to be three distinct perspectives on the potential role of geoengineering. The first one sees it is as a route for buying back lost time in the international mitigation negotiations. For others, it represents a dangerous manipulation of Earth systems and it is essentially unethical. Lastly, geoengineering is seen strictly as an insurance policy against major mitigation failures. However, the latter overlooks the possibility that some options may offer the possibility of stabilizing atmospheric carbon concentrations at lower costs than some forms of conventional mitigation. But even with improved technology, reducing emissions might not be enough to sufficiently reduce the risk of climate change.
In the context of policy proposals, countries should seriously fund research on the use of sulphate aerosols as part of the SRM approach, which in the future could be used as a complementary solution to addressing climate change alongside mitigation policies. Currently, very few countries are funding geoengineering including China, Norway, and Germany, among others. It is important that we do not treat mitigation and SRM geoengineering efforts as mutually exclusive. If anything, the most reasonable approach would be to see them as strategically complementary.
Photo courtesy of NPS Climate Change Response.
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