“Human salvation lies in the hands of the creatively maladjusted.”
– Martin Luther King Jr.
IT WASN’T LONG AGO THAT “tree hugger” was a term of derision, and in some circles it still is. Those circles do not, however, include the major logging companies and the armies of hard-hatted chainsaw wielders who work for them. To the bemusement of the more extreme eco-weenies, many in the industry have become true believers.
The iconic image from the confrontational past was from an old-growth forest in the Pacific Northwest, Washington as I recall. A young woman in a frilly white frock was perched on a makeshift platform 20 meters up the bole of a forest giant, a 400-year-old hemlock. She was, quite literally, hugging the trunk, all the while yelling at the group of men standing below, just behind a police line. Some were reporters, but others, the ones in yellow hard hats, were fellers for the logging company, and they were losing pay for every hour the hugger did her hugging. I remember one, his face grim, starting his chainsaw to drown out the young woman’s imprecations, the angry buzzing also drowning out the clicking of media cameras. I remember thinking that she had better stay where she was, because the chainsaw was a menacing thing, and the anger in the air was palpable.
Over the next 30 years, as the action moved from staged forest dramas to politics and boardroom-driven public relations, many things changed. For one, protesters in frilly frocks vanished, replaced by pro-bono corporate lawyers in business suits. For another, the forest companies found their customers’ sensibility shifting. More and more, customers were demanding wood from sustainably managed forests, and urban-based lumber companies were in turn exerting pressure on the foresters. It was enough to affect profits, and boardrooms responded.
But those weren’t the main changes. Long before other industries, North American and European foresters understood the calamitous effects of climate change. Massive tracts of wild northern hemisphere woods were beginning to die. Pests that had been inhibited by severe winters now survived, killing trees as they moved north. At the same time, species that had been exquisitely attuned to a certain temperature range and annual rainfall began to wither, and some of those, too, died. The forests were migrating north, but like refugees in the human world, their movement was neither orderly nor uniform, but chaotic and sometimes fatal.
Hugging trees, as a metaphor for preserving the world’s forest cover, turned out to be a really good thing. We understand better, now, why this is so.
Industrial carbon capture and sequestration (CCS) may or may not work (see below for an analysis of this improbable idea), but the fact that carbon can be captured and stored is a commonplace of elementary biology. Trees and other plants have been doing it forever, without direction, without compulsion, without regulation, just doing it because that’s what trees and grasses do. Up to 30 percent of the world’s greenhouse gas emissions are related to land use and land use changes, and no climate-change strategy can succeed without taking that into account. Arresting global deforestation and fixing agricultural practices worldwide are important not just to preserve biodiversity in tropical forests or for improving food yields, important as these are. They represent a truly large-scale fix to global warming. Forget about turning your phone charger off, if you like. But don’t neglect the forests.
Recent studies have shown that the biomass of tropical forests, the density of living things, has been increasing over the past few decades, the product of increasing CO2 concentrations in the air. The forests are thriving on more carbon, and are doing their best to help with its sequestration. This is true in northern Australia, in the Amazon, in the African forests of Congo and Cameroon, as well as in those parts of Southeast Asia where forests survive. Cutting them down dramatically reduces natural CO2 sequestration, and keeping them alive is not, it turns out, a frivolous endeavor. Some of the numbers for deforestation are untrustworthy, but a plausible estimate is that the world is losing tropical forest at a rate of 7.3 million hectares per year, and for every hectare somewhere between 200 and 600 tons of carbon are added to the atmosphere.
These numbers have become widely accepted, and it’s not hard to find efforts at stopping the carnage, by the multinational forestry product companies, as well as by governments and NGOs. REDD, for Reducing Emissions from Deforestation and Degradation, for example, is an initiative of an alliance called ClimateWorks, made up of foundations, wealthy individuals, and some governments, with two complementary aims: to stop tropical deforestation by rewarding countries and local peoples for forest preservation, and to help change farming practices to reduce soil-based emissions. REDD’s aim is to help reduce greenhouse gas emissions by 12 gigatons by the year 2030. There’s other good news too. By 2010, Amazon deforestation in Brazil had dropped a startling 75 percent below its 2004 peak, despite vastly increased food production – a consequence of sound policy prescriptions, better science, tougher environmental laws and pressure from consumers.1
Different cultivation methods on farms also help. Using more organic culture and fewer nitrogen-rich fertilizers cuts down on nitrous oxide emissions. “No-till” farming is good too, because tillage, while it does eliminate weeds, also exposes nonliving organic matter to oxygen, thus releasing its carbon dioxide. Another way is to use more perennial grains and more rotational grazing, minimizing the need for fertilizers.
David Montgomery, a scientist with the Earth and Space Sciences department at the University of Washington, in Seattle, has compiled data from around the world that suggest pretty conclusively that conventional agriculture degrades soil much faster than it can be created, by several orders of magnitude. Montgomery has concluded that no-till farming could reduce erosion to levels close to soil production rates, and that organic farming methods are capable of preserving – and in the case of degraded soils, improving – soil fertility.2 Australian farmer Angus Maurice calls this “no-kill cropping.”
Eliminating nitrogen fertilizers alone would remove two gigatons a year from the atmosphere. If all the practices above were introduced and used consistently, REDD’s 12-gigaton target could be exceeded. Easily.
The evidence suggests that plenty of things can be done in the interim, either in prevention, in mitigation, or in solution, while we await the more fundamental issues of politics and economics. Many of the other greenhouse gases – black carbon or soot, methane and tropospheric aerosols, and hydrofluorocarbons (HFCs) – are shorter-lived than CO2, and exist in lesser quantities, but still contribute significantly to global warming. Their abatement could buy time to begin the transformation to a noncarbon economy and give us a way of turning down the thermostat while we work at transforming society. Some of these things seem easy, and are. Some of them seem desperate, and are.
One of the easiest places to start is with a venerable pollutant well known in Victorian times – soot, the component of smoke that belches from diesel engines and inefficient cooking stoves, coal fires, and forest fires. Evidence suggests that black soot may be responsible for more than half the warming experienced to date, and perhaps more in the Arctic – black is a particularly effective warming agent in snowy regions, and it works in more tropical areas too. A study led by Veerabhadran Ramanathan of the Scripps Institution of Oceanography found that the brown clouds of pollution over South Asia had increased solar heating of the lower atmosphere by 50 percent. Most of the world’s soot currently comes from China and India. Another research report, by NASA climate modeler Drew Shindell, was published in 2009 in Nature Geosciences, and is now widely accepted, even making its way into a speech by Hillary Clinton. “Short-lived carbon forcers like methane, black carbon, and tropospheric ozone contribute significantly to the warming of the Arctic,” she said. “Because they are short-lived, they also give us an opportunity to make rapid progress if we work to limit them.”3 Indeed, black-carbon particles remain in the air for just a matter of weeks. If they could be eliminated, the effect would be considerable, and quick.
There are two ways to get rid of black carbon. We could clean up diesel emissions, which can be done by a simple regulatory change, since the technology is widely available and relatively cheap. And we could invest heavily in alternative cooking stoves, which would have the added benefit of improving human health, since soot causes variety of cardiovascular and respiratory diseases, and kills thousands of people a year. Better cooking stoves might sound trivial to those in the developed world, but carbon-fueled cooking is still the norm for billions of people. Dozens of prototypes exist, including a robust solar cooker that needs no fuel at all. Their acceptance in prototype testing in India and other places has been good.
Efforts to prevent methane emissions exist too, though they could be better funded. The Obama administration’s Methane to Markets program is already under way, providing money and expertise to help other countries capture methane from landfills and farms, and especially from rice paddies and coal mines. Once set in train, these programs actually produce energy at a profit instead of letting the gas ascend into the air, where it does its harm. Again, the evidence suggests that if more methane were captured in this way, the results would be dramatic.
Hydrofluorocarbons (HFCs) are mostly used in refrigeration and, ironically, were introduced by industry to replace the ozone-depleting chlorofluorocarbons. HFCs don’t destroy ozone, but they are 1,400 times as potent as CO2 as a warming agent, and already make up 2 percent of the world’s greenhouse gas emissions. The solution is simple and needs no complicated international treaty to impose: simply add HFCs to the globally mandated list of regulated substances. The Montreal Protocol was set up in 1989 to deal with ozone depletion. Its regulators have done a superb job, and there is no reason they can’t do the same with HFCs.
In addition to these easy steps, dozens more complex plans for our salvation have been developed. Al Gore’s “We Can Solve It” campaign, a project of his Alliance for Climate Protection, is getting most of the admittedly meager media attention; its entirely laudable goal is “to build a movement that creates the political will to solve the climate crisis.” The plan known as “Repower America” is an offshoot of the WE campaign. Another Gore-sponsored project is “Option 13,” which describes itself as “an international policy change and grassroots education campaign to help broker a post-2012 global agreement that broadens and builds on Kyoto, and works for both industrializing and developed nations.” The Solar Energy Association has a master plan in which the sun plays a starring role. The Wind Energy Association has a plan too, starring, not too surprisingly, wind. An entity called the Apollo Alliance has a plan, and so does a consortium of large companies, among them oil giants, called the American Climate Action Plan. The Post Carbon Institute has a number of predictably sensible plans, as does, of course, the UN. Greenpeace has a scattering too. So does Lester Brown’s Worldwatch Institute in Washington, DC. There’s a lovely plan called DESERTEC, which involves the Sahara Desert and its searing sunshine. We may not be moving to solution any time soon, but we sure are planning.
These plans contain interesting and useful advice, although many overlap. Hardly any have come to grips with the numbers, or the sheer scale, of the changes needed, and simply keep asserting that the future of renewable energy is “huge,” never matching the huge potential to the huge problem. All share a basic optimism that solving global warming will be easy – if only we adopt this or that attitude, this or that policy, elect this or that leader. Some are plausible, others merely tendentious, but most are worthy. None mentions the population issue. Not one confronts the problem of economic growth (beyond assuming that we will go on striving for it). Almost all promise “green jobs” aplenty, and little economic pain.
Let’s take a closer look at one of these plans. The WE campaign divides its tasks into three simple ideas: the adoption of a clean-energy economy, the shift to renewable energies, and enhanced energy efficiency.
The clean-energy economy section is essentially a push for elected leaders to act:
Absent policies from government, the private sector may continue to invest in old-fashioned, polluting technologies. More than 70 coal plants without technology to capture carbon pollution are now being considered [in the U.S.] … A clean energy economy is a win for American jobs. A recent report showed that investment in a clean and efficient economy would lead to over 3 million new green-collar jobs, stimulate $1.4 trillion in new GDP, add billions in personal income and retail sales, produce $284 billion in net energy savings, all while generating sufficient returns to the U.S. treasury to pay for itself over ten years … A report released by the United Steelworkers and the Sierra Club, for example, found that thanks to the growth of wind energy, approximately 5,200 manufacturing jobs could be created in Iowa alone over the next decade. Additional studies have found that thousands more jobs could be created in other states that have suffered industry job losses and that welcome the opportunity to train workers for the new energy economy.
The third section, on increased energy efficiency, suggests some ways of achieving it, among them more efficient buildings, more efficient cars, and making appliances more efficient. All of them sensible.
The second section is the heart of the plan, and reviews the major renewables. Wind power, “connected through a national grid, could provide at least one-third of our total electricity needs.” Solar thermal? “Just a small area of solar thermal in the Southwest could supply all of the U.S. electricity needs.” Photovoltaics? “If these systems were installed on all sunny buildings in the U.S., we could supply at least one-quarter of our electricity needs.” Geothermal? “United States is the leading producer of geothermal power, producing enough electricity from underground hot rocks for more than 2 million homes. Experts say that we could have 15–30 times as much power over the next few decades thanks to recent advances in geothermal technology.”
There is much that is sensible here too, but the numbers are drivel, and use rhetorical tricks to make the points. How small is a “small area of solar thermal”? How many wind turbines would be needed to provide a third of America’s energy? The plan doesn’t say. What it does say is that if all of American industry, buildings, and transportation became highly efficient, you could prevent CO2 emissions equivalent to “six times the weight of the Empire State Building.” How big is that? The plan gives no comparatives, and no estimate of the size of the task. And more than 5,000 new jobs in Iowa! That sounds like a lot. But the oil and gas industry, which these plans would phase out, currently employs 1. 6 million Americans, coal mining hundreds of thousands more.
Wonks can go to the Repower America Web site, which gets considerably more specific, listing a dozen scenarios, all of which would ultimately end up with 100 percent clean-energy mix by the year 2020. Scenario A envisages reduced demand of 28 percent through efficiency drives, keeping nuclear and hydro at current rates (23 percent of the total), and ramping up wind and solar thermal. Scenario B reduces the need to drastically ramp up wind by assuming that some 20 large coal plants will succeed in capturing and storing their emissions. Both scenarios assume some modest contributions from biomass, geothermal, and other technologies. The planners understand that the actual mix of technologies is not altogether predictable, and that “a variety of configurations [will be] possible.” New nuclear, however, remains a no-go zone in all the proffered scenarios.
Can’t we just clean up fossil fuels, and go on using them? At least until they run out?
This apparently simple question desperately needs an answer, because no matter how it is calculated, the global economy will still be dependent on coal and oil for another few decades. While oil looks like it is beginning its final decline, and coal is acknowledged to be devastating the planet, demand keeps expanding and no other sources will be ready in time for the inevitable crunch.
Fossil fuels are pure miracles, yet we continue to use them casually and unthinkingly. We burn oil idling in traffic jams. We burn “natural” gas to char hamburgers, and use up vast train-loads of coal so we can burn toast at any hour of the day, or cool down our houses when they are too hot, or heat them when they are too cold. We burn vast quantities of fossil fuels to make the plastics for our computers and iPods, yet we think that these devices are environmentally benign. We burn even more to fire the furnaces that make the 30-meter blades for the wind turbines that we consider a viable alternative to older ways of doing business. We plan a future with hybrid cars and electric vehicles, forgetting that the asphalt those cars will drive on comes from our petroleum reserves (and has recently increased from $175 a ton to more than $1,000). Indeed, we seldom stop to think much about these fuels, or what the “fossil” part of the term means. Most of us don’t think at all about the carboniferous epoch, in which the leaves and dead things that now make our fuels were laid down, so many long ages ago, or how long it would take to make more – maybe another 240 million years or so, more than 100 times the entire lifespan of homo sapiens. We’re using up fossil fuels in an eye blink of time, and when they’re gone, they will be gone for good.
Because fossil fuels are so miraculous, and have become so ubiquitous, we can’t just rip out a coal-burning plant and drop in a few wind turbines, and solve the problem that way. Alternative energies are critical to the future, but will not be sufficient on their own in the short or even medium term. All our current alternatives (with the exception of nuclear power) have energy densities far lower than fossil fuels, and none of them can supply energy as cheaply, abundantly, or conveniently in the time frame we have available. Our entire economy – infrastructure, buildings, roadways, transport, electricity, farming – has been designed and constructed to suit the unique characteristics of the coal-oil-gas trinity.
How then are we to manage the transition and ensure that fossil-fuel use is as benign – or as little malevolent – as possible?
One way, as we will discuss in the next chapter, is to increase energy efficiency – to recycle energy, making use of all the energy in any fuel, even recapturing its waste heat. This is doable and amply proven, and will greatly help. We must also switch from the dirtier fossil fuels, primarily coal, to natural gas as much as possible. It’s not clean, but it is cleaner than coal, and the most recent estimates of recoverable gas reserves give us about 60 years’ worth at current rates. We can also use methane. The massive known reserves of methane hydrates found in many parts of the world could present some relief from energy woes. Or, if the fears of some environmentalists are realized and methane is released massively through careless mining, it could precipitate a worse climate crisis than the one we are already facing. There are persuasive arguments either way.
If we must go on using fossil fuels for some time, as seems the case, the challenge becomes to prevent the CO2 they produce from escaping into the atmosphere, where it does its harm. The fossil-fuel industry has pinned its hopes on this notion, which it calls “carbon capture and storage” (or, sometimes, carbon capture and sequestration, CCS for short), but it remains largely theoretical and has many articulate critics.
CCS – if it works – can be applied to coal- and oil-burning generating plants, and at refineries and other large centralized places. It is of no use, however, for smaller things like the emissions from car and truck tailpipes. It is almost always discussed in the context of coal, for coal, more than the other fossil fuels, remains an unlovely product. It is the dirtiest of all fuels. Burning coal helps to pollute the world’s streams, rivers, and oceans with mercury, arsenic, and other dangerous chemicals. But can the harm coal causes can be averted? Is CCS workable? Or is “clean coal,” a phrase beloved of marketers in the pay of fossil-fuel companies, an oxymoron? Environmentalist James Hansen calls the phrase “the dirtiest trick governments can play on their citizens,” and he is far from alone. Even BusinessWeek magazine calls the technology unproven and hypothetical, decades away from commercial application. Amory Lovins, chairman of the Rocky Mountain Institute in Snowmass, Colorado, has called clean coal “a marketing mantra” with no basis in reality. On the sequestration part of the process, the pithiest criticism has come from people like Ray Hobbs of the Arizona Public Service, a utilities regulator, who thinks trying to bury CO2 is crazy: “We spend enormous amounts of money to dig holes to get carbon out of the ground, and the best fix we can come up with is to dig more holes to put it back in? That’s something your dog might think to do.”4
Others think it not only practical, but necessary. Economist Nicholas Stern’s massive 700-page Review on the Economics of Climate Change, compiled for the British government, called it essential. The International Energy Agency says the world must equip more than 200 power plants with CCS technology by 2030. The British government in 2009 said it would no longer approve any new coal plants unless they captured and stored all their emissions, although Secretary of Energy and Climate Change Ed Miliband, now Labour’s leader, gave no hint at how this would be done.
The capture part of CCS is theoretically manageable, though everyone acknowledges that it will be very expensive – perhaps more expensive than spending the money on alternatives. But no one actually knows whether sequestration will work. No one knows if the CO2 pumped into those holes in the ground will actually stay there or, like some kind of malign and vaporous vampire, refuse to die.
To say that capture is theoretically manageable is to admit that no one has yet done it on any scale. A few small demonstration projects exist, but the only test at power station scale was an American government-sponsored project called FutureGen, announced by George Bush in his 2007 State of the Union address. FutureGen was to be a 250-megawatt near-zero-emissions coal plant near the town of Mattoon, Illinois, where there was a happy conjunction of available coal, access to the grid, and terrain that could, in theory, hold the carbon dioxide. It was to be a partnership between the U.S. Energy Department and a consortium made up of 20 American and international energy companies called the FutureGen Industrial Alliance Inc. Each put up $20 million to $30 million to get the thing going. But costs ballooned almost as fast as a budget for the Olympic Games, and when estimates added up to $1.8 billion on an original budget of $800 million, the Bush administration pulled the plug, without anything built. A few smaller projects, in the states of Florida, West Virginia, Ohio, Minnesota, and Washington were also canceled, for the same reason – mounting costs and an uncertain outcome.5
In February 2010, the Obama administration set up a task force that was supposed to suggest how between five and 10 commercial CCS plants could be online and working smoothly by 2016, and put up $4 billion as seed money. One of the plants was to be FutureGen 2.0, a new design that would capture 90 percent of emissions, for a total of 1.3 million tons a year. (Alas, the county in which the plant was to be built immediately announced it would not allow CO2 storage anywhere within its boundaries.) Still, Energy Secretary Steven Chu, in a flurry of rhetoric to prove the Obama government was committed to greenness in all its incarnations, said that CCS was crucial to their plans: “Developing this technology is critically important for reducing greenhouse gas emissions in the U.S., and around the world.” Environmental Protection Agency boss Lisa Jackson added to the verbal emissions, declaring that “by encouraging efforts to develop clean coal technology we will obtain new tools to reduce greenhouse gas emissions, create jobs, and make our nation more competitive in the global race for clean energy technology.” And late in 2009 GE announced it would power the world’s largest CCS plant to date, under Barrow Island off Australia’s west coast; it is supposed to deal with 3.4 million tons of CO2 per year by 2012.
On various occasions, Canada has promised to reduce its emissions a piffling 20 percent under 2005 levels by 2050, one of the weakest targets in the developed world, and is relying almost exclusively on CCS. In 2009, Alberta doled out about $2 billion to fund a scattering of projects to collect and store emissions. Late in the year, the federal government and Alberta announced a joint $558 million for the Alberta Carbon Trunk Line project, which is projected to store 14.6 million tons of carbon a year, for a probable total of 2 billion tons, far larger than the Australian project. The secondary purpose of the ACTL is to use the CO2 to recover new oil from previously depleted wells, a technique called enhanced oil recovery, or EOR. The annual target of 14. 6 million tons of CO2 is not insignificant, but it still doesn’t come close to making a global impact. Consider that the two governments have been diligently promoting the expansion of the tar sands, which will increase CO2 by far more than they are offering to store, and in the process use 20 percent of Canada’s natural gas (a clean fuel) to produce the tar sands oil (a dirty one). Ottawa has promised another $125 million for CCS research, with promises of up to $3 billion more over the next decade. It is almost certain that most of this will be money wasted.
Burying CO2 comes with it own problems. First, you have to find geological formations where storage is feasible. Shallow is no good. You need the pressure found at one-kilometer depth or more to turn the gas from its volatile natural state to a supercritical form, a quasi-liquid state in which it is more likely to stay in place. The geology needs to be similar to that in which oil and gas naturally occur – friable rock with many fractures, into which the gas can be injected and covered with an impermeable cap to prevent it leaking to the surface. Depleted gas and oil mines and wells do fit the bill.
The few small demo projects that have been undertaken include a depleted oil field in Saskatchewan, near the town of Weyburn, which stores small quantities of CO2 from a coal gasification plant across the border in North Dakota. For decades now BP has been running a similar project in Algeria, near Saleh, scrubbing the CO2 from a natural gas well and injecting it back underground (where, so far, it has stayed). Total is undertaking another relatively tiny project in France, and the Norwegian oil company Statoil has been injecting CO2 under the North Sea seabed since 1996. Britain has joined the Norwegians, agreeing to help finance a study of further North Sea sites, hoping, according to a euphoric press release, that so much room would be found they could essentially rent storage space to other nations.
But no one really know what happens, or will happen, underground. The gas may simply bubble to the surface again. Or, as William Marsden recounts in Stupid to the Last Drop, it may explode out of the ground: “If Jane and Cameron Kerr’s farm near Weyburn is any example – where the [gases did explode out of the ground and] hydrocarbons contaminated their gravel pit pond and their household well”6 – there could be serious flaws in this technology. What if it simply doesn’t work?
The other problem with storage is the sheer scale of what is needed. It’s all very well to say, as Norway’s minister of petroleum and energy, Terje Riis-Johansen, has, that “carbon capture and storage offers the potential to reduce CO2 emissions by as much as 85 to 95 percent from fossil fueled power plants”; or as an ad from the oil giant Royal Dutch Shell in The Economist put it, “In our view of the future, CO2 could be captured and stored at 90 percent of all coal- and gas-fired power plants in developed countries by 2050, and at least 50 percent of plants in developing countries.” But no one will acknowledge the billions of tons of CO2 that are being produced every year, and would have to be stored.
One study found that to reduce emissions from coal by just 10 percent, a volume of CO2 equivalent to all the oil pumped globally in a year would need to be captured, transported, and stored underground, at a cost of trillions of dollars. The three showcase projects listed above each manage to store about 1 million tons a year, which sounds like a lot. But a single large power plant can produce 10 million tons of carbon and sulphur dioxide annually – and there are thousands of them. Where are you going to put that? Then consider that the U.S. electricity industry alone produces 1.5 billion more tons of CO2 a year, so you’d need another 1,500 storage sites, all of them with appropriate geology and transportation potential. In total, the U.S. generates almost 6 billion tons annually – in mass, as the economist Jeff Rubin has calculated in a vivid image, the equivalent of 76 million Abrams battle tanks, the largest and most fearsome tanks in the world.7 How are we going to hide 76 million army tanks deep underground – every year? So far, no geologist has thought this even remotely plausible. Yet the global CO2 total is much larger still – around 30 gigatons every year.
Even if it proves to work flawlessly, it is obvious that CCS is not enough to save us on its own. But this is a case where every little bit really does help – removing and storing as much CO2 as possible will buy us time to do what we know we must, which is to move beyond fossil fuels. It is a question of tricky timing. We need CCS to help us through the transition, and therefore should continue its development. But by putting barrels of money into its research and implementation, we risk diverting needed funding from the development of alternatives – which are what will save us in the end.
If none of the above gets done, or if the technologies don’t work, or if we’re too late, geo-engineers have suggested interim ways of cooling the planet. These would be counted as emergency fixes, to be used only if disaster seems inevitable. It’s like dialysis for kidney failure, as James Lovelock puts it in The Vanishing Face of Gaia, “valuable [only] as a way to buy time, to survive until something better comes along.”8
Some of these geo-engineering suggestions are simple in theory, but ferociously difficult in execution. All are ingenious, many fearfully expensive, a good many insane, some practical, almost all with unforeseeable consequences. The whole notion drives most environmentalists up the wall – don’t bother to reduce emissions, just create something even bigger and uglier, and with unforeseen consequences, to “fix” the problem, thereby almost certainly making things worse. This strategy, they argue, encourages practices that got us into this mess in the first place. “It’s like a junkie figuring out new ways of stealing from his children,” Meinrat Andreae, an atmospheric scientist at the Max Planck Institute, says.9
It is only the fear that the world’s climate is nearing a tipping point that has propelled otherwise skeptical scientists to take the idea seriously. Several conferences have been held, one in January 2004 at Cambridge University, another in November 2006 by the Carnegie Institution for Science and NASA, and a third at Harvard in November 2007, attended by two of the preeminent climate change scientists, James Hansen and Kerry Emanuel. Hansen was and still is against geo-engineering, but he went anyway. Scientists should at least understand it, he allowed, so they can head off politicians’ more hare-brained implementations. Early in 2010 some 200 experts in geosciences and other scientific and policy disciplines met at Asimolar on the Monterey Peninsula and declared that geo-engineering had become indispensable, though they hastily added that such schemes should be introduced with “humility,” with public forums to decide which schemes are “viable, appropriate, and ethical.”
Questions remain. If geo-engineering works, and we can control the planet’s temperature, what is the optimal temperature? And whose hand would be on the thermostat? Will countries be able to manipulate climate for their own benefit?
Most of these techniques are not worth exploring in detail, because they are either impractical (would take far too much effort and money) or they very likely won’t work. For example, scientists have suggested scattering iron filings on thousands of kilometers of the oceans’ surface to encourage algae growth, which would then absorb CO2; this is known, not surprisingly, as the Geritol Solution. What small tests were made, however, were discouraging.
Space-based ideas include placing a giant sunshade at the Lagrange Point, the position between the Earth and the sun where the combination of gravity and centripetal forces allows an object to remain stationary without expending energy. Alas, further research suggests that a sunshade 4.1 million square kilometers big, about half the size of Brazil, would be effective in offsetting only half the global warming expected. It would also require spacecraft vast either in size or number, an unlikely feat for a civilization that struggles to get a single space shuttle into near-Earth orbit.
The biggest, if most ludicrous, notion to control the planet’s temperature is to move the whole Earth into a cooler cosmic neighborhood. This could be done by the same techniques scientists have already suggested for deflecting asteroids or comets heading toward Earth – only this time they would steer them closer, not further away, and use their gravitational tug to nudge the planet’s orbit into a safer, colder part of the solar system. “The technology is not far-fetched,” NASA’s Greg Laughlin told the London Observer. “We don’t need raw power … we just require delicacy of planning and manoeuvring.”10
Perhaps the most plausible geo-engineering idea involves injecting large amounts of sulphate aerosols into the atmosphere, shielding the Earth from a proportion of solar radiation by increasing its reflectivity. This is what major volcanic eruptions do. A study in Nature by atmospheric scientist Peter J. Gleckler and others demonstrated pretty clearly that nineteenth-century ocean warming and sea-level rise were substantially reduced by the colossal eruption of Krakatoa in 1883.11 The eruptions of the volcano El Chichón in 1982 and Pinatubo in 1991 confirmed the observations. The long-lived debris from Pinatubo, water droplets laced with sulfuric acid, reflected enough sunlight to cool the Earth an average of 0.5°C for a year or two. That’s about the same amount of warming as over the past century.12 We were reminded, once again, of the power of volcanoes to affect events when the little Icelandic volcano Eyjafjallajökull went off early in 2010. It was a tiny thing, really, but managed to disrupt trade and travel across a large swath of Europe.
Estimates of how much sulphur would have to be injected into the air have varied widely, but it would take perhaps 50,000 flights a year by cargo aircraft carrying sulphur aloft to equal Pinatubo – and the flights would have to be continued indefinitely. Such an effect might not even be very noticeable – it would just make for more hazy days, as though the whole world were living in China.
A more extravagant idea, but nevertheless a plausible one, was suggested by David Keith of the University of Calgary.13 It involves the levitation (using a chemical trick of sunlight itself to do the actual lifting, and therefore needing no rockets) of billions of nano-scale metallic disks that would reflect a proportion of sunlight back to space. These disks would naturally elevate themselves to 40 or 50 kilometers above the earth, well above the ozone layer. (Note that “billions” of such particles wouldn’t be very large – and likely wouldn’t weight much more than a kilogram or two. Nevertheless, Keith acknowledges that their manufacture to the precise scales necessary would be expensive – though less costly, he points out, than current projections for cutting emissions.)
Not surprisingly, the opposition to these notions is fierce. One contribution to the debate in the pages of Nature suggested that a nuclear war could have the same result, if that was what we wanted.14 Others pointed out that sulphate aerosols, as well as Keith’s nano-scale flying saucers, might lessen planetary rainfall, threatening food supplies for many millions of people, and would further encourage the acidification of the oceans, already a problem. The sulphate would also threaten the ozone layer.15
There are some easier things to do. Change agricultural practices and stop deforestation. Clean up the soot problem. CCS can help us through the fossil fuel transition – if only in a small way – but it is not the savior that industry is looking for. We can also radically increase our energy efficiency, as we will see.
And hold back deliberate atmospheric pollution as a last-ditch emergency fix if everything else goes awry.