Geoengineering Earth: We've been doing it for ages; now it looks as though we'll have to undo it
The term geoengineering is relatively new. It follows and alters the word terraforming, coined by a science fiction writer 70 years ago to denote the act of making another planet more Earth-like. When I was writing my Mars trilogy of novels in the 1990s, I described the deliberate alteration of that planet to give it an Earth-like biosphere; as I did so, it occurred to me that we were already doing to Earth what my characters were doing to Mars.
But to say that we were "terraforming Earth" was painfully ironic, suggesting as it did that we had damaged our home planet so badly we now needed to take drastic steps to restore it to itself.
When geoengineering entered the lexicon, many bristled at the word's hubristic implication that we had the knowledge and power to engineer anything so large and complex as our planet. Still, the term has stuck, and it has essentially come to mean doing anything technological, on a global scale, to reduce or reverse the effects of climate change.
Defined this way, the idea makes almost everyone uneasy -- including the scientists who introduced it, most of whom agree that the best solution to our climate problem remains rapid decarbonization. But these scientists have also noticed that our progress on this front hasn't been good. We lack the political mechanisms, or maybe even the political will, to decarbonize. So people are right to be worried, and some of them have therefore put forth various geoengineering plans as possible emergency measures: problematic, but better than nothing.
Objections to geoengineering appeared immediately. Many people have expressed doubt that the proposals would work, or believe that a string of negative unintended consequences could follow. Merely discussing these ideas, it has been said, risks giving us the false hope of a "silver bullet" solution to climate change in the near future -- thus reducing the pressure to stem carbon emissions here and now.
These are valid concerns, but the fact remains: Our current technologies are already geoengineering the planet -- albeit accidentally and negatively.
Consider that significant percentages of the world's wetlands have been drained, and large swaths of its forests cut down. Ecosystems have been devastated by overdevelopment. We've raised atmospheric CO2 levels by about 100 parts per million, and average global temperatures have gone up accordingly. Our oceans have soaked up so much of the carbon we've dumped into the atmosphere that the seas have measurably acidified. On land, hundreds of species have gone extinct. And far worse damage is sure to follow if this inadvertent geoengineering campaign of ours is allowed to continue.
For the rest of history, we will be required to work at repairing the damage we've already done to the biosphere. Geoengineering, then, has become our ongoing responsibility to life on this planet, including all human generations to come. All of which leads to the question: Can we actually design and accomplish any geoengineering projects that would mitigate or reverse climate change? Putting aside issues of political capability, are any of these projects physically possible?
The answer appears to be: yes, some of them are. Maybe.
Some of the most talked-about proposals entail removing CO2 from the atmosphere or not letting it enter in the first place. One of them calls for trapping it and storing it deep underground. The concept behind carbon capture and sequestration has already been demonstrated to work; many scientists think it merits further study. And to those who say our most urgent goal is holding atmospheric carbon levels as close as possible to 350 parts per million, it's attractive for obvious reasons.
Another oft-discussed idea involves shooting sulfur dioxide particles into the upper atmosphere in order to reflect incoming sunlight back into space. While this, too, would appear plausible from a mechanical standpoint, the veneer of plausibility only adds to serious concerns about unknown secondary effects, as well as worries that by taking an action such as this one, the root issue -- our need to curb carbon emissions -- would remain unaddressed. As a result, this is one of the most controversial geoengineering plans to date. It practically glows with the hubris of weird science; it scares people.
When ideas move from the atmosphere to the ocean, they get even scarier. One of the most hotly debated sequestration plans would have us dumping iron dust into the ocean to promote algal blooms, which would eventually sink, taking their carbon load with them. Last July, a California entrepreneur and geoengineering advocate tried doing this off the coast of British Columbia -- and found himself in trouble with Canada's environmental ministry, the U.S. National Oceanic and Atmospheric Administration and the broader scientific community.
Among their concerns is that actions like his could disturb the ocean's nutrient balance and food chains. But they also worry about accelerating ocean acidification -- a problem for which there exists no geoengineering solution.
Some have proposed dumping pulverized limestone into the ocean to neutralize its acid; the United Kingdom's Royal Society, however, has concluded that the amount required would be equal to the White Cliffs of Dover, and then some. This is a fine addition to the parade of images that feature prominently in the eco-disaster subgenre of British science fiction, and it reminds us of an important lesson: We simply don't have the power to reverse all that we've done.
So geoengineering the atmosphere looks iffy at best; geoengineering the oceans even worse. What about the land?
We've been altering our landscapes for thousands of years, of course, so there's ample "proof of concept." But just as technology has aided us in the task of deforesting and draining our wetlands, so too does it now provide us with the capability to do things like reforest and rehydrate.
Thinking about such potential reversals makes me believe the definition of geoengineering should be broadened. Our actions have a global impact; it's good to be reminded of this by giving that impact a name. Were we to take up hybrids and electric cars in great numbers, for example, could that be considered geoengineering? Under an expanded definition, absolutely. Whatever we do as a civilization of 7 billion is inevitably going to have a geoengineering effect.
What about that number, 7 billion? Could stabilizing our population count? Again, yes. And we know of one good way to achieve this goal: promoting women's legal and social rights. Wherever they expand, population growth shifts toward the replacement rate. This particular geoengineering technology nicely illustrates how the word technology can't be defined simply as machinery; it includes things like software, organizational systems, laws, writing, even public policy.
Were we to change our lifestyles in order to conserve resources, could that be thought of as geoengineering?
Consider the example of Zurich, which is hoping to become a 2,000-watt society. The city government is embarking on a grand experiment, encouraging citizens to live on 2,000 watts of electricity per person, per year -- what each of us would have were the world's electricity distributed equally. (Right now, Americans average more than 10,000 watts a year, Bangladeshis about 200.) Zurichers who have participated report no diminishment in their quality of life; on the contrary, they say that their lives have been augmented by new feelings of accomplishment and virtue.
As a science fiction novelist trying to write the realism of the 21st century, I'm convinced that these broader definitions of geoengineering better describe what we'll all be doing in decades to come. In my books I've imagined people salting the Gulf Stream, damming the glaciers sliding off the Greenland ice cap, pumping ocean water into the dry basins of the Sahara and Asia to create salt seas, pumping melted ice from Antarctica north to provide freshwater, genetically engineering bacteria to sequester more carbon in the roots of trees, raising Florida 30 feet to get it back above water and (hardest of all) comprehensively changing capitalism.
These fictional methods range from promising to risky to crazy. All of them make for interesting stories, I hope -- and also compel us to think about what we can do to help Earth's biosphere, both individually and collectively.
We have many opportunities to act, and those actions scale up. If we take advantage of them, we can create a permaculture that works in balance with our planet over the long haul. We'll all be geoengineers -- without ever even having to try any of the more dangerous experiments we now think of when we come across that word.
First Published December 9, 2012 12:00 am