Climate Change Series: The Geoengineering Debate


It sounds like science fiction: Massive engineering projects to deflect the sun's rays in an attempt to reduce the warming effects of climate change. And yet, with the continuing rise in global greenhouse gas emissions, geoengineering has become an increasingly common topic of discussion among climate scientists, policy makers and national security experts.

Jason Blackstock, John Steinbruner and Armond Cohen examine the arguments for, and challenges presented by, the prospect of geoengineering the climate.

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Jason Blackstock is the deputy director of the Centre for Engineering Policy at University College London and a visiting fellow at the Institute for Science, Innovation and Society at the University of Oxford.

When Mount Pinatubo in the Philippines erupted in 1991, it injected millions of tons of sulfur into the stratosphere. This sulfur formed small aerosol particles that stayed in the stratosphere for roughly two years and acted like little mirrors, reflecting sunlight into space and cooling the planet by a half-degree Celsius. Eruptions like Pinatubo got scientists thinking: Could humans reduce global temperatures by intentionally spraying aerosols into the stratosphere?

It turns out to be alarmingly easy. For just a few billion dollars a year, it appears possible for a fleet of a couple dozen aircraft to spray enough sulfur particles into the stratosphere to lower temperatures by a couple degrees Celsius. This cost is well within reach of many countries — or, for that matter, major cities, large corporations or even wealthy individuals.

If this or other solar geoengineering techniques just cooled the climate system with no other effects, we'd probably already be doing them. But when volcanoes like Mount Pinatubo cool the climate system down, they also change precipitation patterns. If we start spraying aerosols into the stratosphere to cool the temperature, we would also change where, when and in what quantities rain falls. If, as a result, monsoon season in South Asia were affected, the food and water supplies for roughly two billion people would be seriously jeopardized.

 The grand challenge is figuring out who gets to decide if or when climate change has become severe enough to justify the risks associated with geoengineering.

Because of these uncertainties many people are understandably very reluctant to experiment. The grand challenge is figuring out who gets to decide if or when climate change has become severe enough to justify the risks associated with geoengineering.

Geoengineering presents the opposite of the "collective action" problem of trying to get everyone to cut greenhouse gas emissions. Instead it represents unilateral action, and that raises numerous political, scientific and moral challenges. But our collective failure to reduce greenhouse gas emissions is leading more people and groups to consider geoengineering as a serious option.

There are risks with even discussing geoengineering options. If geoengineering is determined to be a "plan B" for addressing climate change, it may give corporations and governments license to say, "If we're going to geoengineer in 20 years anyway, we don't need to worry about reducing carbon emissions now."

Once technology development is underway, questions over who gets to own and control the technologies will not be far behind. And who decides what environmental risks are acceptable when it comes to real-world field-testing?

Ultimately, geoengineering makes it possible for people to control the climate. This raises a fundamental question: Who should control the climate? The White House? The China Politburo? An international organization? Vulnerable communities that are already getting hammered by the effects of climate change?

It remains to be seen. These are early days; Scientists only began to seriously study geoengineering options quite recently. For now, the main questions are: Who should do what research? And when? Who should have access to generated information and technologies? Who should decide about testing those technologies?

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John Steinbruner is professor of public policy at the School of Public Policy at the University of Maryland and director of the Center for International and Security Studies at Maryland (CISSM).

In many Pakistani villages, residents go without power for 16 hours a day or more. Electric power is so unreliable and people are so frustrated that the Taliban has found it can mobilize political support and even induce people to attack power stations out of frustration.

This is serious trouble being driven in a major way by climate change that is beyond the government's ability to control. And it's just one example of the growing national and global security challenges climate change presents.

In the coming years, societies around the world will feel the effects of climate change, and some of them will not handle it well. Pakistan is a good example. It's an fragile society, with a very prominent agricultural sector. It is highly dependent on the Indus River watershed, where 30 to 40 percent of river flow is derived from glaciers and melting snow.

In the coming years, societies around the world will feel the effects of climate change, and some of them will not handle it well.

Pakistan faces sharp allocation trade-offs:  Should it use its scarce water resources to grow crops (which provide 65 percent of the nation's foreign currency earnings), or to generate electricity? Pakistan also faces competing demands for irrigation from different provinces in the watershed. Because of the country’s tenuous political situation, Pakistan favors irrigation over power generation, favors Punjab over Sindh province, and uses unrealistically high estimates of how much water is, in fact, available.

Thus, there's a division of interest within Pakistan, which pits businesses dependent on electrical power against agriculture dependent on irrigation, and pits both against the country's growing urban areas that depend on the availability of water resources. These tensions are already generating riots and violence within Pakistan on an almost daily basis.

We have to anticipate severe, even catastrophic, failures in some societies — whether in Pakistan or elsewhere — as the extraordinarily heavy burdens of adapting to climate change occur with increasing frequency and severity over the next three decades. Right now, we are not prepared for that future.

Nations subjected to severe pressures may well consider it a matter of supreme national interest to lower global temperatures “by any means necessary,” including geoengineering. Manipulation of the atmosphere, however, will almost certainly be considered a supreme global interest by the world as a whole.

Precisely because it is a growing national and global security threat, we — the U.S. and other nations — must prepare to manage geoengineering contingencies. As part of that effort, we will need to transform the security relationships among the U.S., the EU, Russia, China and India to elevate our interests in mutually productive collaboration.

We also need to establish protocols for global vetting of geoengineering field trials and ultimate approval. There are several countries, including our own, that are capable of conducting geoengineering operations — such as injecting sulfate aerosols into the stratosphere — on their own and within their own airspace.

View slides from John Steinbruner's presentation here.


Armond Cohen is co-founder and executive director of the Clean Air Task Force, and founded the Conservation Law Foundation’s Energy Project.

Four realities help inform what we need to do to stabilize the climate: 1.) limiting climate damage ultimately means near-zero emissions; 2.) most of the truly zero carbon options face significant challenges of scale and cost; 3.) we’ll need a lot of innovation — better options, if you will — to get where we need to go; 4.) in the meantime, we’ll probably need some damage control.

Why near-zero emissions? Think of the climate as a bathtub. Right now we're pouring about 35 billion tons per year of carbon dioxide into the atmosphere (the bathtub), while draining only tens of million tons per year out. If we don't slow down the flow and shut off the spigot during this century, the bathtub will overflow and create a climate humans have never experienced.

We have never had a greater technical challenge. We need to start now.

Zero emissions means we have to replace the earth's existing energy infrastructure with zero carbon energy. This is a significant challenge; Current energy infrastructure is 87 percent powered by fossil fuels. Then we need to double the size of that carbon-free infrastructure to meet increased global demand. To accomplish such a massive task, we can't afford to take any options of the table, but all the options have significant challenges.

Let’s start by looking at electricity, which represents about 40 percent of the global CO2 problem. If there is a two to three-fold increase in global energy demand, increased energy efficiency will only be able to displace a fraction of the resulting CO2. Most of the demand growth will come from the developing world where rapid urbanization and industrialization sparks first-time consumption that will swamp efficiency increases.

Renewables like wind and solar face significant hurdles to scale and cost. Renewables are substantially more expensive than fossil fuels at the point of generation, with the exception of certain onshore wind sites. Also, because the wind doesn’t always blow and the sun doesn’t always shine, maintaining system reliability requires redundant power sources that can be tapped instantly. This alone could double or triple costs.

Carbon capture and storage (CCS), a technology which allows for scrubbing carbon from coal or gas, has been commercially demonstrated but would require quick scale-up, ultimately at the size of the global oil business. CCS currently adds 50 to 75 percent to the cost of a gas or coal plant.

Nuclear power provides roughly 20 percent of U.S. electricity today, and is our largest carbon free source. It is highly scalable, but will need to come down in price to be broadly competitive. There are promising new designs to modularize plants, build them in factories at smaller, shippable sizes, and use less accident-prone fuels, coolants and systems, but they don’t exist yet in commercial practice.

We need to invest in research, development and demonstration (RD & D) for all of the zero carbon energy innovation and technologies above. Currently, only 5 percent of the Defense Department’s RD & D budget is spent on energy. That has to change.

Finally, we need to be thinking hard about a “plan B” to mitigate climate consequences should we fail to reduce emissions in time. We are already climate- or geoengineering the planet with massive carbon emissions, so the case for inaction in this sphere is far from self-evident.

We need a better toolkit and unprecedented technological innovation across many fronts. And we must do this in a matter of a few decades. We have never had a greater technical challenge. We need to start now.


This program aired on April 26, 2013. The audio for this program is not available.


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