Should We Use Science to Manipulate the Climate?

Should we use science-based proposals for alleviating global warming such as putting particles in the upper atmosphere to deflect solar energy? Do we know enough about the risks of such wide-scale manipulation of the environment to be sure we know how this would turn out?

Scientists weigh risks of climate 'techno-fixes', by Moises Velasquez-Manoff, The Christian Science Monitor: Faced with the specter of a warming planet and frustrated by the lack of progress..., some scientists ... seek a way to give humanity direct control over Earth's thermostat.

Proposals run the gamut from space mirrors deflecting a portion of the sun's energy to promoting vast marine algal blooms to suck carbon out of the atmosphere. The schemes have sparked a debate over the ethics of climate manipulation, especially when the uncertainties are vast and the stakes so high. For many scientists, the technology is less an issue than the decision-making process that may lead to its implementation. [Graphic showing some of the proposals.]

Environmental policy driven purely by cost-benefit analyses cannot, they say, effectively point the way on large issues like climate change. But even as many scientists caution against unintended, even catastrophic consequences of tinkering with climate, they concede that the more tools humankind has to confront a serious problem, the better.

Others wonder if the mere hint of a quick-fix solution will only provide a false sense of security and hamper efforts to address the root problem: carbon emissions from a fossil fuel-based economy. And then there's the trillion-dollar question: In a politically fractured world, how will technologies that affect everyone be implemented by the few, the rich, and the tech-savvy? ...

[G]eoengineering, ... subtracting a fraction of the sun's energy from the earth equal to that trapped by human-emitted greenhouse gases ..., is not a new idea, but only recently has it moved toward the scientific mainstream. In 2006, Nobel Laureate Paul Crutzen ... published a paper on injecting particles into the upper atmosphere to reflect incoming sunlight and cool the earth. Climate scientists have since run scenarios on climate models and first reports found that it might work. In November last year, NASA cohosted a conference on the topic. ...

By some estimates, geoengineering has the added allure of being cheaper than curbing emissions. Economists say that decarbonizing the economy will cost around 2 percent of the gross domestic product; putting reflective aerosols into the upper atmosphere will cost about one-thousandth of that, says Ken Caldeira, a climate scientist at ... Stanford University.

But others say the discussion over mitigation seems to have gotten ahead of itself. Why talk about fixing symptoms when we have the technology to address the root cause? ... Bill McKibben, author of "The End of Nature" and more recently "Deep Economy." [says]... "before geoengineering, let's do a little policy engineering first."

History seems to support Mr. McKibben's critique. The Clean Air and Clean Water Acts of the 1960s and 1970s, which cost more than the estimates for curbing emissions today, are seen in retrospect as absolutely the right thing to have done. That such costs are now viewed as untenable speaks to the shortcomings of the cost-benefit approach that has driven environmental policy for the past 25 years, says Frank Ackerman, ... of ... the Global Development and Environment Institute at Tufts University...

Simply put, economic analyses can't deal with far-reaching, long-term problems like climate change or geoengineering, he says. There are too many unknowns. ... For this reason, many call global warming a moral issue, not an economic one. There are certain relationships that cannot be assigned numerical values. "If you just looked at it from a cost-benefit point of view, Central Park is completely irrational," says Dale Jamieson, director of environmental studies at New York University. "Yet, nobody would think that the fact you can sell Central Park to Donald Trump is reason to do it."

Others point out that the mere mention of a techno-fix for climate change could have unintended consequences. If people know that someone will bail them out of catastrophe, they're more inclined to engage in risky behavior, says David Keith ... of ... the University of Calgary. Statistically speaking, those with flood insurance suffer the worst flood damage, he says. And because geoengineering may lead to greater risk-taking – in this case by continuing to emit copious amounts of CO2 – "it's clearly not, in some global sense, economically optimal," says Mr. Keith.

But Mr. Cascio points out that fail-safe technologies could also drive humanity in the other direction. If people understand that these technologies are a terrible last resort, the specter of their deployment may serve as a deterrent the way mutually assured destruction (theoretically) saved the world from a nuclear holocaust during the cold war. The parallel has to be made clear: "You are consciously trying to alter the complex systems that govern how our planet operates," he says. "Do that the wrong way, and you potentially kill everyone." ...

Because climate change has winners and losers – one country's breadbasket dries up while another's desert blooms – unilateral change becomes a sticky prospect. Manipulation – even if it's viewed as a corrective measure – will inevitably impinge on another's newfound good fortune. "Even if you're very confident that you can make things better, that doesn't necessarily give you the right to do that if, in fact, you're affecting other people's interests," says Professor Jamieson.

Ken Caldeira posits another possibility: "You could imagine some kind of arms race of geoengineering, where one country is trying to cool the planet and another is trying to warm the planet," he says.

I think the last claim is a bit far-fetched, but I want to focus on the claim that economics has little to offer, and more generally on the tensions between environmentalists, scientists, and economists. First, I don't get this statement:

There are certain relationships that cannot be assigned numerical values. "If you just looked at it from a cost-benefit point of view, Central Park is completely irrational," says Dale Jamieson, director of environmental studies at New York University.

Consider, for example, just one aspect of this - tax collections from rising property values near the park:

As early as the 1850s, landscape architect Frederick Law Olmsted justified the purchase of land for New York's Central Park by noting that the rising value of adjacent property would produce enough in taxes to pay for the park.

By 1864, Olmsted could document a $55,880 net return in annual taxes over what the city was paying in interest for land and improvements. By 1873, the park--which until then had cost approximately $14 million--was responsible for an extra $5.24 million in taxes each year.

There are all sorts of other costs and benefits to be considered, or course, but the point is that it's not clear that Central Park is necessarily irrational, i.e. that the costs exceed the benefits.  I would also quarrel with the assertion that the benefits cannot be approximated using standard econometric methodology, though as explained below in general such valuations may involve normative judgments.

This is a standard dispute between economists and some environmentalists (as John Whitehead and Tim Haab discuss often at Environmental Economics). We had to fight to get economics courses into our environmental studies program here, and that is common across programs. It's better that it once was, but communication between the two groups could be further improved. I think environmentalists have trouble trusting that economists are interested in something other than maximizing GDP at the expense of the environment, and here is resistance to the idea that certain things can be assigned a value. There are other problems as well including the fact that economists have been very poor ambassadors of their profession.

I don't get this either:

Statistically speaking, those with flood insurance suffer the worst flood damage... And because geoengineering may lead to greater risk-taking – in this case by continuing to emit copious amounts of CO2 – "it's clearly not, in some global sense, economically optimal," says Mr. Keith.

That having flood insurance and suffering flood damages are correlated doesn't prove that flood insurance causes risky behavior, though it's certainly possible. It's just as easily explained by people in high risk areas taking out insurance at a higher rate than people in lower risk areas. And the "not economically optimal" part is just the standard moral hazard argument about insurance when it does cause people to take on extra risk, nothing new there. There are ways to design policy to minimize such distortions and the distortions do not, in and of themselves, rule out insurance as an option.

One last note. It's true that cost-benefit analysis cannot provide all the answers. But that's not because economics fails to give us any guidance. The tools of economics have allowed us to see that there is an ethical judgment involved in the choice of the social rate of discount needed to value the costs and benefits of climate change policy. It is a matter of comparing the well-being of current and future generations, an inherently normative judgment. Thus, even when we cannot assign precise numbers, the theoretical tools of economics can help us focus our attention on the important aspects of problems and understand where economics can help, and where the political process must take over and balance competing interests to resolve the normative issues involved in policy choices.