A QUARTER OF CENTURY passed since the first global treaty on climate change, the UN Framework Convention on Climate Change. Humanity’s record in meeting its climate promises is dismal. The concentration of carbon dioxide in the atmosphere has increased by 15% since 1994. The average global temperature, compared to the 1951-80 norm, has increased by about 0.5 ° C during this period. And in 2018, annual emissions hit their highest level ever. To have a good chance of halting global temperature rises of more than 1.5 ° C above the pre-industrial standard, by 2030 annual greenhouse gas emissions must fall by almost half of that of the pre-industrial standard. at 2010 levels, according to the Intergovernmental Panel on Climate Change. . They certainly won’t.
However, a much hotter and hostile climate could still be avoided through geoengineering: tinkering with climate processes to reduce global temperature. (The possibilities are described in detail in “The Remade Planet” by Oliver Morton, a reporter for this newspaper.) The more climate targets are missed, the more geoengineering is likely to be used and the more urgent it is that governments understand delicate political economy.
The Earth is warming because carbon dioxide and other greenhouse gases build up in the atmosphere, altering the balance of energy coming from the sun and back into space. For a generation, the main policy response has been to set emission reduction targets, in the hope that new laws and technologies will allow them to be met. But decarbonizing an industrialized economy is extremely difficult. The US Energy Information Agency estimates that the share of renewables in the global energy mix will reach 18% of the total by 2050, up from just over 13% today. Vast systems of fossil-fueled infrastructure – tens of thousands of power plants, a billion vehicles – remain in place. The most ambitious decarbonisation programs, like that of Germany Energiewende, have made progress. But developed economies will only meet their climate targets if they reduce all their emissions faster than the peak rate Germany hit in 2017 for decades. And developing economies must either achieve the unprecedented feat of growing without fossil fuels or stop growing altogether.
Such costs could be incurred were it not for the terrible political economy of climate change mitigation. It is the carbon stock in the atmosphere that determines the extent of warming, not the flux. The current warming is the consequence of past emissions. As a result, the cuts are tedious when done but only bring benefits in the future. In addition, the benefits of reducing emissions are spread globally as the costs – of new power plants, vehicles, etc. – are local. This creates an incentive to free-ride: keep using dirty fuels while hoping that the efforts of other countries will avert future disaster. To decarbonize knowing that the payoffs will take decades to arrive, and even then only if all the other big countries act as well, is asking a lot of a political system.
Solar geoengineering is different. Large volcanic eruptions cool the planet by releasing plumes of sulfur dioxide into the upper atmosphere. These eventually turn into an aerosol mist of reflective sulfate particles, which prevent a small portion of the sun’s energy from making its way to the Earth’s surface. Humans could try something similar to offset the warming effect of greenhouse gas emissions. Building and maintaining a reflective particle pumping system would be expensive, but much less than rebuilding the world’s energy infrastructure. If successful, it would immediately begin to offset the greenhouse effect. And a single determined country could go it alone. America could potentially launch a program at a cost of less than Nasaannual budget, and, if all goes according to plan, stop heating up in its tracks. At one point, a large country may find that the single costs of warming alone are greater than the single costs of a geoengineering program. If political economy makes reducing emissions nearly impossible, it seems to make geoengineering something inevitable.
Take a closer look, however, and solar geoengineering would be anything but politically straightforward. This is not a solution to climate change, on the one hand, but a stopgap. Until emissions are reduced, this must continue, or sudden and catastrophic warming will result. Bypassing sunlight does nothing to solve other emissions-related problems, such as ocean acidification. The effects of cooling, such as warming, would be global and would undoubtedly elicit an international response. Some countries might oppose unilateral climate change. Others might fight over how much cooling should take place. The effects of warming and cooling (as well as changes in things like precipitation) could be geographically unequal in politically explosive ways. Some climate models suggest that the geoengineering that left China at a comfortable temperature could cool India below the level at the end of the 20th century.
The Winds of Winter
Perhaps a collective approach to geoengineering could be negotiated. The possibility of unilateral action could focus the minds. Compared to dramatic and binding emission reductions, this would be cheaper and more immediately effective, and therefore perhaps easier to agree. A quieter decarbonation could then take place.
Still, any agreement would be difficult. The longer the discussions, the more likely unilateral action is, perhaps in response to a climate emergency. Certain powerful countries would undoubtedly see the climatic changes which would be imposed on them as a security threat. If one of them develops a geoengineering capability, others might feel pressured to do so as well. Countries could seek to act first rather than risk having one rival reshape the global climate as it sees fit, and suspend all others – or see everyone lagging behind, resulting in dangerous warming for all. More likely, geoengineering would not relieve humanity of the need to cooperate on a global scale. Having embarked on the great experiment of industrialization, countries must either work together or burn together.
This article appeared in the Finance and Economics section of the print edition under the headline “A Hot Mess”