The 1970s saw a revolution in Western attitudes toward the natural environment. Concern with pollution, deforestation, and species extinction exploded. With the rise of these concerns came an ambivalent attitude toward technology and the wealth it was producing: some said that human beings are destructive to the environment in direct proportion to their power. This immediately suggested that technology and higher living standards were bad, being inherently destructive. "Wealth" came to imply environmental destruction.
The revolution in attitudes toward the environment has changed the idea of wealth. Our national statistics may not reflect itnot every last citizen or politician may agreebut the concept that genuine wealth includes not just houses and refrigerators, factories and machines, cars and roads, but also fields and forests, owls and wolves, clean air, clean water, and wilderness has taken deep root in minds and in politics. "The wealth of nature" has come to include nature as a value in itself, not merely as potential lumber, ore, and farmland.
As a consequence, greater wealth has begun to mean cleaner wealth, greener wealth. Richer countries can afford more expensive, more efficient equipmentscrubbers on smokestacks, catalytic converters on carsand so they can produce goods with less environmental impact. This trend gives at best a hint of the future.
Lester Milbrath, director of the Research Program in Environment and Society at the State University of New York at Buffalo, observes, "Nanotechnologies have the potential to produce plentiful consumer goods with much lower throughput of materials and much less production of waste, thus reducing carbon dioxide buildup and reducing global warming. They also have the potential to reduce waste, especially hazardous waste, converting it to natural materials which do not threaten life." James Lovelock states that "The future could be good if we regain a sense of purpose and embrace the new industries based on information and nanotechnology. These add enormous value to molecular-sized pieces of matter, and need not be a threat to the environment as were the heavy polluting industries of the past."
Should we boast of high technology while industry still can't produce without polluting? Pollution is a sign of low technology, of inadequate control of how matter is handled. Inferior goods and hazardous wastes are two sides of one problem.
With processes based on molecular manufacturing, industries will produce superior goods, and by virtue of the same advance in control, will have no need of burning, oiling, washing with solvents and acids, and flushing noxious chemicals down their drains. Molecular-manufacturing processes will rearrange atoms in controlled ways, and can neatly package any unwanted atoms for recycling or return to their source. This intrinsic cleanliness inspired environmentalist Terence McKenna, writing in the Whole Earth Review, to call nanotechnology "the most radical of the green visions."
This green vision will not be fulfilled automatically, but only with effort. Any powerful technology can be used for good or ill, and nanotechnology is no exception. Today, we see scattered progress in environmental cleanup and restoration, some slowing of ecological destruction, because of organized political pressure buoyed by a groundswell of public concern. Yet for all its force, this pressure is spread desperately thin, fighting enormous resistance rooted in economic forces.
But if these economic forces vanish, the opposition will crumble. Often, the key to success in battle is to give one's opponents an attractive alternative to fighting. The most powerful cry of the antigreen opposition has been that clearing and polluting the land offer the only path to wealth, the only escape from poverty. Now we can see a clean, efficient, and unobtrusive alternative: green wealth, compatible with natural wealth.
We've already seen how molecular manufacturing can provide clean solar energy without paving over desert ecosystems, and how clean energy and common materials can be turned into abundant, efficient goods, also cleanly. With care, sources of chemical pollutioneven of excess carbon dioxidecan, step by step, be eliminated. This includes the pollutants responsible for acid rain, as well as ozone-destroying gases, greenhouse gases, oil spills, and toxic wastes.
In each case, the story is about the same. Acid rain mostly results from burning dirty fuels containing sulfur, and from burning cleaner fuels in a dirty way, producing nitrogen oxides. We've seen how molecular manufacturing can make solar cells cheap enough and rugged enough to use as road surfaces. With green wealth, we can make clean fuels from solar energy, air, and water; consuming these fuels in clean nanomechanical systems would just return to the air exactly the materials taken from it, along with a little water vapor. Fuels are made, fuels are consumed, and the cycle produces no net pollution. With cheap solar fuels, coal and petroleum can be replaced, ignored, left in the ground. When petroleum is obsolete, oil spills will vanish.
The greenhouse gas of greatest concern is carbon dioxide, and its main source is the burning of fossil fuels. The above steps would end this. The release of other gases, such as the chlorofluorocarbons(CFCs) used in foaming plastics, is often a side effect of primitive manufacturing processes: foaming plastic will hardly be a popular activity in an era of molecular manufacturing. These materials can be replaced or controlledand they include the gases most responsible for ozone depletion.
The chief threats to the ozone layer are those same CFCs, used as refrigerants and solvents. Molecular manufacturing will use solvents sparingly (mostly water), and can recycle them without dumping any. CFC refrigerants can be replaced even with current technology, at a cost; with nanotechnology, that cost will be negligible.
Toxic wastes generally consist of harmless atoms arranged into noxious molecules; the same is true of sewage. With inexpensive energy and equipment able to work at the molecular level, these wastes can be converted into harmless forms. Many need never be produced in the first place. Other toxic wastes contain toxic elements, such as lead, mercury, arsenic, and cadmium. These elements come from the ground, and are best returned to the location and condition in which they were found. With nanotechnology, moreover, there will be little reason to dig them up in the first place. Nanotechnology will be able to break materials down to simple molecules and build them back up again. Need it be said that this will permit complete recycling?
It is fair to say that eliminating these sources of pollution would be a major improvement. There doesn't seem to be much more to say, aside from the usual caveats: "Not immediately," "Not all at once," and "Not on a predictable schedule." No one wants to make and dump wastes; they want something else, and get wastes as by-products. With a better way to get what people want, dumping wastes can be stopped.
People will also be able to get what they want while reducing their resource consumption. As materials grow stronger, they can be used more sparingly. As machines grow more perfectin their motors, bearings, insulation, computersthey will grow more efficient. Materials will be needed to make things, and energy will be needed to run them, but in smaller amounts. What is more, nanotechnology will be the ultimate recycling technology. Objects can be made extremely durable, decreasing the need for recycling; alternatively, objects can be made genuinely biodegradable, designed at the molecular level to decompose after use, leaving humus and mineral grit; alternatively, they can be made of microscopic snap-together pieces, making objects as recyclable as structures built and rebuilt out of a child's blocks; finally, even objects not designed for recycling can be taken apart into simple molecules and recycled regardless. Each approach has different advantages and costs, and each makes current garbage problems go away.
Still, even after twentieth-century industry is history, its toxic residues will remain. Cleaning up waste dumps with today's technology has proved so expensive and ineffective that many in the field have all but given up hope of really solving the problem. What can be done with post-breakthrough technologies?
Nanotechnology can help with the cleanup of these pollutants. Living organisms clean the environment, when they can, by using molecular machinery to break down toxic materials. Systems built with nanotechnology will be able to do likewise, and to deal with compounds that aren't biodegradable.
Alan Liss is director of research for Ecological Engineering Associates, a company that uses knowledge of how natural ecosystems function to address environmental problems such as wastewater treatment. He explains how cleanup could work: "The more we learn about the ecosystem, the more we find that functions are managed by particular organisms or groups of organisms. Nanotech 'managers' might be able to step in when the natural managers are not available, thereby having a particular ecological activity occur that otherwise wouldn't have happened. A nanotech manager might be used for remediation in a situation where toxicants have destroyed some key members of a particular ecosystemsome managerial microbes, for example. Once the needed activities are reinitiated, the living survivors of the stressed ecosystem can jump in and continue the ecosystem recovery effort."
FIGURE 10: ENVIRONMENTAL CLEANUP
To see how nanomachines could be used to clean up pollution, imagine a device made of smart materials and roughly resembling a tree, once it has been delivered and unfolded. Above ground are solar-collecting panels; below ground, a branching system of rootlike tubes reaches a certain distance into the soil. By extending into a toxic waste dump, these rootlike structures could soak up toxic chemicals, using energy from the solar collectors to convert them into harmless compounds. Rootlike structures extending down into the water table could do the same cleanup job in polluted aquifers.
Most atmospheric pollutants are quickly washed out by rain (turning them into soil- and water-pollution problems), but some air pollutants are longer lasting. Among these are the chlorine compounds attacking the ozone layer that protects the Earth from excessive ultraviolet radiation. Since 1975, observers have recorded growing holes in the ozone layer: at the South Pole, the hole can reach as far as the tips of South America, Africa, and Australia. Loss of this protection subjects people to an increased risk of skin cancer and has unknown effects on ecosystems. The new technology base will be able to stop the increase in ozone-destroying compounds, but the effects would linger for years. How might this problem be reversed more rapidly?
Thus far, we've talked about nanotechnology in the laboratory, in manufacturing plants, and in products for direct human use. Molecular manufacturing can also make products that will perform some useful temporary function when tossed out into the environment. Getting rid of ozone-destroying pollutants high in the stratosphere is one example. There may be simpler approaches, without the sophistication of nanotechnology, but here is one that would work to cleanse the stratosphere of chlorine: Make huge numbers of balloons, each the size of a grain of pollen and light enough to float up into the ozone layer. In each, place a small solar-power plant, a molecular-processing plant, and a microscopic grain of sodium. The processing plant collects chlorine-containing compounds and separates out the chlorine. Combining this with the sodium makes sodium chloride-ordinary salt. When the sodium is gone, the balloon collapses and falls. Eventually, a grain of salt and a biodegradable speck fall to Earth, usually at sea. The stratosphere is soon clean.
A larger problem (with a ground-based solution) is climatic change caused by rising carbon dioxide (CO2) levels. Global warming, expected by most climatologists and probably under way today, is caused by changes in the composition of Earth's atmosphere. The sun shines on the Earth, warming it. The Earth radiates heat back into space, cooling. The rate at which it cools depends on how transparent the atmosphere is to the radiation of heat. The tendency of the atmosphere to hold heat, to block thermal radiation from escaping into space, causes what is called the "greenhouse effect." Several gases contribute to this, but CO2 presents the most massive problem. Fossil fuels and deforestation both contribute. Before the new technology base arrives, something like 300 billion tons of excess CO2 will likely have been added to the atmosphere.
Small greenhouses can help reverse the global greenhouse effect. By permitting more efficient agriculture, molecular manufacturing can free land for reforestation, helping to repair the devastation wrought by hungry people. Growing forests absorb CO2.
If reforestation is not fast enough, inexpensive solar energy can be applied to remove CO2 directly, producing oxygen and glossy graphite pebbles. Painting the world's roads with solar cells would yield about four trillion watts of power, enough to remove CO2 at a rate of 10 billion tons per year. Temporarily planting one-tenth of U.S. farm acreage with a solar cell "crop" would provide enough energy to remove 300 billion tons in five years; winds would distribute the benefits worldwide. The twentieth century insult to Earth's atmosphere can be reversed by less than a decade of twenty-first century repair work. Ecosystems damaged in the meantime are another matter.
The space near Earth is being polluted with small orbiting projectiles, some as small as a pin. Most of the debris is floating fragments of discarded rocket stages, but it also includes gloves and cameras dropped by astronauts. This is not a problem for life on Earth, but it is a problem as life begins its historic spread beyond Earththe first great expansion since the greening of the continents, long ago.
Orbiting objects travel much faster than rifle bullets, and energy increases as the square of speed. Small fragments of debris in space can do tremendous damage to a spacecraft, and worsetheir impact on an spacecraft can blast loose yet more debris. Each fragment is potentially deadly to a spacefaring human crossing its path. Today, the tiny fraction of space that is near Earth is increasingly cluttered.
This litter needs to be picked up. With molecular manufacturing, it will be possible to build small spacecraft able to maneuver from orbit to orbit in space, picking up one piece of debris after another. Small spacecraft are needed, since it makes no sense to send a shuttle after a scrap of metal the size of a postage stamp. With these devices, we can clean the skies and keep them hospitable to life.
We've spoken of waste that just needs molecular changes to make it harmless, and toxic elements that came from the ground, but nuclear technology has created a third kind of waste. It has converted the slow, mild radioactivity of uranium into the fast, intense radioactivity of newly created nuclei, the products of fission and neutron bombardment. No molecular change can make them harmless, and these materials did not come from the ground. The products of molecular manufacturing could help with conventional approaches to dealing with nuclear waste, helping to store it in the most stable, reliable forms possiblebut there is a more radical solution.
Even before the era of the nuclear reactor and the nuclear bomb, experimenters made artificially radioactive elements by accelerating particles and slamming them into nonradioactive targets. These particles traveled fast enough to penetrate the interior of an atom and reach the nucleus, joining it or breaking it apart.
The entire Earth is made of fallout from nuclear reactions in ancient stars. Its radioactivity is low because so much time has passedmany half-lives, for most radioactive nuclei. "Kicking" these stable nuclei changes them, often into a radioactive state. But kicking a radioactive nucleus has a certain chance of turning it into a stable one, destroying the radioactivity. By kicking, sorting, and kicking again, an atom-smashing machine could take in electrical power and radioactive waste, and output nothing but stable, nonradioactive elements, identical to those common in nature. Don't recommend this to your congressmanit would be far too expensive, todaybut it will some day be practical to destroy the radioactivity of the twentieth-century's leftover nuclear waste.
Nanotechnology cannot do this directly, because molecular machines work with molecules, not nuclei. But indirectly, by making energy and equipment inexpensive, molecular manufacturing can give us the means for a clean, permanent solution to the problem of wastes left over from the nuclear era.
Shortages often spur environmental damage. Faced with a food shortage, herdsmen can graze grasslands down to bare dirt. Faced with an energy shortage, industrial countries can approve destructive projects. The growth of population and the consumption of resources by twentieth-century industry have placed growing pressures on Earth's ability to support us in the manner to which we have become accustomed.
The resource problem will look quite different in the twenty-first century, with a new technology base. Today, we cut trees and mine iron for our structures. We pump oil and mine coal for our energy. Even cement is born in the flames of burning fossil fuels. Almost everything we build, almost every move we make, consumes something ripped from the Earth. This need not continue.
Our civilization uses materials for many things, but mainly to make things with a certain size, shape, and strength. These structural uses include everything from fibers in clothing to paving in roads, and most of the mass of furniture, walls, cars, spacecraft, computersindeed, most of the mass of almost every product we build and use. The best structural materials use carbon, in forms like diamond and graphite. With elements from air and water, carbon makes up the polymers of wool and polyester, and of wood and nylon. A twenty-first-century civilization could mine the atmosphere for carbon, extracting over 300 billion tons before lowering the CO2 concentration back to its natural, pre-industrial level. For a population of 10 billion, this would be enough to give every family a large house with lightweight but steel-strong walls, with 95 percent left over. Atmospheric garbage is an ample source of structural materials, with no need to cut trees or dig iron ore.
Plants show that carbon can be used to build solar collectors. Laboratory work shows that carbon compounds can be better conductors than copper. A whole power system could be built without even touching the rich resources of metal buried in garbage dumps.
Carbon can make windows, of plastic or diamond. Carbon can make things colorful with organic dyes. Carbon can be used to build nanocomputers, and will be the chief component of high-performance nanomachines of all kinds. The other components in all these materials are hydrogen, nitrogen, and oxygen, all found in air and water. Other elements are useful, but seldom necessary. Traces would often be ample.
With a new technology base making recycling easy, there need be no steady depletion of Earth's resources, just to keep a civilization running. The sketch just made shows that recycling just one form of garbageexcess atmospheric CO2can provide most needs. Even 10 billion wealthy people would not need to strip the Earth of resources. They could make do with what we've already dug up and thrown away, and they wouldn't even need all of that.
In short, a twenty-first-century civilization with a population of 10 billion could maintain a high standard of living using nothing but waste from twentieth-century industry, supplemented with modest amounts of air, water, and sunlight. This won't necessarily happen, yet the very fact that it is possible gives a better sense of what the new technology base can mean for the relationship between humanity, resources, and the Earth.
In The Green Consumer, Elkington, Hailes, and Makower define a green product as one that:
Is not dangerous to the health of people or animals
Does not cause damage to the environment during manufacture, use, or disposal
Does not consume a disproportionate amount of energy and other resources during manufacture, use, or disposal
Does not cause unnecessary waste, due either to excessive packaging or to a short useful life
Does not involve the unnecessary use of or cruelty to animals
Does not use materials derived from threatened species or environments
Ideally, does not trade price, quality, nutrition, or convenience for environmental quality
With its ability to make almost anything at low costincluding products designed for extreme safety, durability, efficiencywithout mining, logging, harming animals or environments, or producing toxic wastes, molecular manufacturing will make possible greener products than any yet seen in a store. Nanotechnology can replace dirty wealth with green wealth.
A central problem in environmental restoration is reversing environmental encroachment. We tend to see land as being gobbled up by housing, because the land where we live generally is. Farming, though, consumes more land, and the variant of farming called "forestry" consumes still more. By rolling back our requirement for farmland, and for wood and paper, nanotechnology can change the balance of forces behind environmental encroachment. This should make it more practical, politically and economically, for people to move toward environmental restoration.
Restoring the environment means returning land to what it wasremoving what has been added and, where possible, replacing what has been lost. We've seen how this can be done, in part, by removing pollutants and some of the pressures for ploughing and paving. A more difficult problem, though, is restoring the ecological balance where the changes have been biological. Much of Earth's biological diversity has been a result of biological isolation, of islands, seas, mountains, and continents. This isolation has been breached, and reversing the resulting problems is one of the greatest challenges in healing the biosphere.
Human meddling with life in the biosphere has caused enormous ecological disruptions. This hasn't involved genetic engineeringby twisting organisms to better serve human purposes, genetic engineering usually leaves them less able to serve their own purposes, less able to survive and reproduce in the wild. The great disruptions have come from a different source: from globe-traveling human beings taking aggressive, well-adapted species from one part of the planet to another, landing them on a distant island or continent to invade an ecosystem with no evolved defenses. This has happened again and again.
Australia is a classic case. It had been isolated long enough to evolve its own peculiar species quite unfamiliar elsewhere: kangaroos, koalas, duck-billed platypuses. When humans arrived, they brought new species. Whoever brought the first rabbits could not have guessed that they, of all creatures, would be so destructive. They soon overran the continent, destroying crops and grazing lands, unchecked by natural competitors or predators. They were joined by invaders from the plant kingdom: the prickly pear, and others.
The Americas have suffered invasions, too: tumbleweed, a bane of the rancher and farmer, is a relatively recent import from Central Asia. Since 1956, Africanized bees have been spreading from Brazil and moving northbut what they displace, in America, are European bees. Africa, in turn, is being invaded by the American screw-worm fly, an insect with larvae that enter an animal's wounds, including the umbilical wound of a newborn, and eat it alive. The story goes on and on.
People have sometimes tried, with a measure of success, to fight fire with fire: to bring in parasitic species and diseases to attack the imported species and keep its growth within some reasonable bounds. Australia's problem with prickly pear was tackled using an insect from Argentina; the rabbits were cut backwith mixed resultsusing a viral disease called myxomatosis: "rabbit pox."
In many parts of the world, native species have been driven to extinction by rats, pigs, and other imported species, and others are endangered and fighting for their lives. Biological controlsfighting fire with firehave advantages: organisms are small, selective, and inexpensive. These advantages will eventually be shared by devices made using molecular manufacturing, which avoid the disadvantages of importing and releasing yet more uncontrollable, breeding, spreading species. Alan Liss spoke of using nanotechnological devices to help restore ecosystems at a chemical level. A similar idea can be applied at a biological level.
The challengeand it is hugewould be to develop insect-size or even microbe-size devices that could serve as selective, mobile, mechanical flyswatters or weed pullers. These could do what biological controls do, but would be unable to replicate and spread. Let's call devices of this sort "ecosystem protectors." They could keep aggressive imported species out, saving native species from extinction.
To a human being or an ordinary organism, an ecosystem protector would seem like just one more of the many billions of different kinds of bugs and microbes in the ecosystemsmall things going about their own business, with no tendency to bite. They might be detectable, but only if you sorted through a lot of dirt and looked at it through a microscope, because they wouldn't be very common. They would have just one purpose: to notice when they bumped into a member of an imported species on the "not welcome here" list, and then either to eliminate it or to ensure, at least, that it couldn't reproduce.
Natural organisms are often very finicky about which species they attack. These ecosystem protectors could be equally finicky about which species they approach, and then, before attacking, could do a DNA analysis to be sure. It would be simplest (especially in the beginning while we're still learning) to limit each kind of defender to monitoring only one imported species.
Each unit of a particular kind of ecosystem-defender device would be identical, built with precision by a special-purpose molecular-manufacturing setup. Each would last for a certain time, then break down. Each kind can be tested in a terrarium, then a greenhouse, then a trial outdoors ecosystem, keeping an eye on their effects at each stage until one gains the confidence for larger scale use. "Larger scale" could still be quite limited, if they aren't designed to travel very far. This built-in obsolescence limits both how long each device can operate and how far it can move: getting control of the structure of matter includes making nanomachines work where they're wanted and not work elsewhere.
The agricultural industry today manufactures and distributes many thousands of tons of poisonous chemicals to be sprayed on the land, typically in an attempt to eliminate one or a few species of insect. Ecosystem protectors could also be used to protect these agricultural monocultures, field by field, with far less harm to the environment than today's methods. They could likewise be used in the special ecosystems of intensive greenhouse agriculture.
Unlike chemicals sprayed into the environment, these ecosystem protectors would be precisely limited in time, space, and effect. They neither contaminate the groundwater nor poison bees and ladybugs. In order to weed out imported organisms and bring an ecosystem back to its natural balance, ecosystem protectors would not have to be very commononly common enough for a typical imported organism to encounter one once in a lifetime, before reproducing.
Even so, as the ecosystem protectors wear out and stop working, they would present a small-scale problem of solid-waste disposal. With the exercise of some clever design, all the machinery of ecosystem protectors might be made of reasonably durable yet biodegradable materials or (at worst) materials no more harmful than bits of grit and humus in the soil. So their remains would be like the shells of diatoms, or bits of lignin from wood, or like peculiar particles of clay or sand.
Alternatively, we might develop other mobile nanomachines to find and collect or break down their remains. This strategy starts to look like setting up a parallel ecosystem of mobile machines, a process that could be extended to supplement the natural cleansing processes of nature in many ways. Each step in this direction will require caution, but not paranoia: there need be no toxic chemicals here, no new creatures to spread and run wild. Missteps will have the great virtue of being reversible. If we decide that we don't like the effects of some particular variety of ecosystem protector or cleanup machine, we could simply stop manufacturing that kind. We could even retrieve those that had already been made and dispersed in the environment, since their exact number is known, along with which patch of ground each is patrolling.
If the making and monitoring of ecosystem protectors seems a lot of trouble to go to just to weed out nonnative species, consider this example of the environmental destruction such species can cause. Sometime before World War II, a South African species of fire ant was accidentally imported into the United States. Today, infested areas can have up to five hundred of these ants per square foot. The National Audubon Societya strong opponent of irresponsible use of pesticideshad to resort to spraying its refuge islands near Corpus Christi when they found these ants destroying over half the hatchlings of the brown pelican, an endangered species.
In Texas, it's been shown that the new ants are killing off native ant speciesreducing biodiversity. The USDA's Sanford Porter states that due to them, "Texas may be in the midst of a genuine biological revolution." The ants are heading west, and have established a beachhead in California. Without ecosystem protectors or something much like them, ecologies around the world will continue to be threatened by unnatural invasions. Our species opened the new invasion routes, and it's our responsibility to protect native species made newly vulnerable by them.
Today, most people are far from the land, tied up in turning the wheels of 20th century industry. In the years to come, those wheels will be replaced by molecular systems that do most of their turning by themselves. The pressure to destroy the land will be less. Time available to help heal the land will be greater. Surely more energy will flow in this direction.
To mend ruined landscapes will require skill and effort. Ecosystem defenders can do flyswatting and weedpulling jobs no humans ever could, but there will also be jobs of shaping, planting, and nurturing. The land has been torn by machines guided by hasty hands, almost overnight. It can gradually be restored by patient hands, whether bare, gloved, or guiding machines able to reshape a ravaged mountain without turning the soil.
The green wealth that can be brought by nanotechnology has raised high hopes among some environmentalists. Again writing in Whole Earth Review, Terence McKenna suggests it "would tend to promote . . . a sense of the unity and balance of nature and of our own human position within that dynamic and evolving balance." Perhaps people will learn to value nature more deeply when they can see it more clearly, with eyes unclouded by grief and guilt.
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