In the summer of 2017, a scientist at Harvard University named David Keith announced he would be raising $20 million for a project called SCOPEX -- Stratospheric Controlled Perturbation Experiment. The project would involve shooting a rocket loaded with sulphur aerosols into the upper atmosphere, exploding the rocket and dispersing the chemicals. The idea is that these aerosols – tiny suspended particles of a chemical that is known to have toxic health impacts – would act as a temporary sunscreen, blocking the rays of the sun and thereby cooling the Earth.
This concept, known as Solar Radiation Management (SRM) raises some profound questions. An SRM program to cool the Earth would require a fleet of planes taking off daily to spray sulphur particles into the upper atmosphere. And that fleet could never stop. If the spraying ever stopped, the continued accumulation of carbon dioxide in the atmosphere, temporarily masked by the sunscreen, would cause a massive and rapid surge in global temperatures. And at some point, no amount of spraying would suffice to lower temperatures.
A major risk is that cooling the Earth this way, or even allowing politicians to use SRM as a tactic to delay immediate action under the Paris Climate Agreement, would ease pressure on governments to cut greenhouse gas emissions, allowing energy companies to continue burning the fossil fuels responsible for climate change. And the long-term impacts on human and environmental health are uncertain. Some studies show that SRM could change weather patterns, including shifting monsoon rains, potentially affecting millions of farmers.
But all of these important risks are overshadowed by an even larger and more profound question. It all comes down to politics. Control over the heating of the Earth means handing the power to someone to regulate the climate system of the entire planet. So who would be in charge? What level of political maturity and ethical sophistication is necessary for anyone to wield such enormous power and use it safely for the benefit of the common good? And because some will benefit more than others, can we expect them to use that power fairly?
Solar geoengineering is being discussed because the big carbon polluting nations are so beset by political, social, and ethical failings that they have shifted the Earth’s climate system in ways that are on track to be catastrophic. And they’ve done so in full knowledge of the consequences.
It’s possible that sulphate aerosol spraying may be able to reduce the rate of warming for a time. Many geoengineering advocates point to the eruption of Mount Pinatubo in the Philippines in 1991, which caused significant atmospheric cooling for two years. But it’s one thing when Mother Nature spews sulphur into the atmosphere, quite another when humans do it. Having a shiny technofix like SRM misdirects attention from the urgent need for political action and the rapid deployment of affordable technologies like solar and wind power.
Many of the same political institutions and financiers who have so mismanaged our emissions of greenhouse gases will now be responsible for deploying a solar shield between the Earth and the Sun, while simultaneously pumping more and more carbon into the atmosphere. What could possibly go wrong? It’s almost impossible to not imagine a scenario in which the financial incentives for “managing” the crisis of global warming are so great, that they will be directly at odds with humanitarian efforts to solve climate change.
With all of these geoengineering approaches -- from BECCS and Air Carbon Capture to SRM and Ocean Fertilization– the precautionary principle must be invoked, which warns of the possibility of harm from making a certain decision when extensive scientific knowledge on the matter is lacking. We certainly don’t know enough about the longterm physical effects on our environment from sustained dispersion of sulphur dioxide. They are likely very significant. But we certainly do know a lot about human nature.
Could we ever trust a small group of individuals enough to give them control over the Earth’s global thermostat? Imagine the power to turn the Earth’s temperature up or down at will, to change the weather in ways that may benefit one group of people over another – China at the expense of India, Europe at the expense of Africa? Should the Kremlin make the decision? Or the the Chinese Communist Party? Or Donald Trump?
Those who endorse geoengineering have put a great deal of thought into countering those who argue that solar geoengineering could unintentionally harm some nations while benefitting others. Scientists like David Keith have said that if solar geoengineering is done carefully enough, these unintentional harms can be avoided. David Keith also holds patents on the technology and would receive billions of dollars in passive income if it were to come to fruition.
But what about the intentional harms? That is, when those who have their hand on the global thermostat use it to deliberately damage their adversaries. After all, the generals have always dreamed of controlling the weather because the weather can give a decisive military advantage. It’s what’s known as a force multiplier.
Any program of solar geoengineering will inevitably involve the military. It’s a strategic issue, and militaries are watching closely. The landmark 2014 report on solar geoengineering by the U.S. National Research Council was partly funded by the CIA. They want to know if adversaries could use it to harm the United States.
Those in charge of climate regulation through sulphate aerosol spraying would be twiddling with the knobs on a weekly or monthly basis. How much should be sprayed? How frequently? At what height? Where on Earth should it be done?
Each decision will affect some more than others. Who should we trust with such power? Scientists who back the idea believe that a cohort of clever, rational scientists would be in charge. But that’s not how the world works.
Even if it did, we may not get a Professor Keith in charge but a Dr. Strangelove. After all, one of the earliest and strongest advocates of sulphate aerosol spraying was Edward Teller, the father of the hydrogen bomb and the real-life model for Dr. Strangelove. He wanted to use nukes to flatten mountains and create new harbours.
Teller celebrated man’s mastery over nature. His protégé and the co-author of Teller’s 1997 paper advocating solar geoengineering was Pentagon weaponeer Lowell Wood. He said of solar geoengineering: “We’ve engineered every other environment we live in – why not the planet.”
Some advocates of solar geoengineering have said that there is nothing inherently desirable about the climate that nature gave us. They have expressed “delight in our new tools” to set the climate wherever we want. But at whose expense?