Creative Solutions to the Problem of CO2?

Chapter 4F

Creative Solutions to the Problem of CO₂?

Those scientists who foresee a catastrophe vehemently disapprove of a wait-and-see attitude. By the time we have conclusive proof, they say, it may be too late. They want to curtail CO₂ emissions now. From a professional philosophical perspective, it appears at first sight that they are right: Under conditions of uncertainty it seems reasonable to move so as to avoid disaster.

First sight, however, might be as misleading in social policy as in love. Dissenters argue that the present conditions of uncertainty do not justify the drastic controls pessimist activists hunger for. They suggest two reasons why.

The first reason is that there may be alternative solutions even if the problem is truly serious. That is, we may be able to avert most, if not all, of the catastrophic scenarios without hindering the world’s industry in a massive scale. They do not have in mind the radical technological alternatives discussed in Chapter 2, e.g., solar power satellites and non-imaging optics, but rather ways of preventing the warming of the atmosphere even if fossil fuels continue to supply the lion’s share of our industrial energy.

Instead of our spending 250 billion dollars a year to reduce CO₂ emissions by 15%, as recommended by environmentalists (in the sort of rough financial estimate that can easily be off by a factor of two, most likely upward), a National Academy of Sciences panel (1992) suggested that we find means to compensate for any undue increase in greenhouse gases. The physicist Gregory Benford has cataloged several such means and has devised more of his own. One simple way to remove a large portion of the increase in CO₂ is to plant more trees. A campaign of reforestation in unused lands can be done for a few billion dollars, enhancing the quality of life, and giving us some breathing room in which to think of longer-term solutions.[1]

Plankton can provide another solution, since they can withdraw a considerable amount of fossil-fuel emissions as well. It is known that plankton are scarce in the polar oceans, in spite of the presence of large reserves of the nitrates and phosphates that plankton normally use. The reason seems to be the absence of iron in those oceans. But surely, John Martin suggests, we could ferry the needed iron dust for a relatively low price. According to Benford, for about ten billion dollars a year we could farm enough plankton to absorb as much as a third of a year’s fossil-fuel emissions.[2] This result is clearly superior to the 15% reduction that the draconian measures of the environmentalists would achieve for the sum of 250 billion!

Not surprisingly, such proposals would not be to the liking of environmentalists such as Bill McKibben, who believe that the only way to slow climate change is to use fewer fossil fuels.[3] The evidence seems to favor Martin’s idea, however. In a week-long experiment off the Galapagos Islands in 1996, 990 lbs. of iron made the waters bloom with plankton, Benford reports, which then covered 200 square miles, suddenly green.[4] This was just one of many successful experiments that have been carried out from 1993 to 2002. Some oceanographers worry that long-scale fertilization over a period of many decades may adversely affect the ocean;[5] but, as we will see below, this proposal has been offered only as a temporary measure.

Other possible solutions involve changing the albedo of the planet: If it reflects more sunlight, it will absorb less energy, and therefore the greenhouse effect will diminish, other things being equal. We might achieve this goal by increasing sulfur emissions in the South Pacific (which would increase cloud cover over the middle of the Pacific Ocean, the darkest and most solar-energy-absorbing area of the world). Or we might, alternatively, make jetliners burn a richer fuel mixture, which would leave a trace of fog high in the atmosphere. According to Benford, this process would offset a year’s worth of U.S. emissions for a mere $10 million!

Readers may worry about the possibility of hidden long-term environmental costs and dangers of such geo-engineering – ideological critics will be certain to do so. But all these suggestions are put forth as reversible experiments. In the case of the iron dumping, for example, if the iron dust is not continuously supplied, the polar ocean will return to its previous state in ten days or so.

The greenhouse problem is thus not a case of having to act in the face of uncertainty so as to avert disaster. For given the possibility of apparently reasonable, and significantly cheaper temporary solutions, the wise course of action is to reduce the uncertainty before imposing drastic permanent solutions. That is, we ought to increase our knowledge of the factors that may influence the warming of the atmosphere, and particularly of the ways they affect each other. We should, thus, attempt to gain a better global understanding of the Earth’s environment. Only then will our worries command the universal respect now demanded by the pessimists.

This result is strengthened by the realization that we know very little about how the global and regional environments interact. This is the second reason adduced by the dissenters. To see what they mean, think about how irrigation and other uses of land affect the local climate. Overgrazing in Northern Mexico makes for temperatures as much as four degrees Celsius hotter than you find in Arizona, just a few dozen meters away. On the other hand, irrigation in the plains of Colorado, where corn and other crops have replaced dry prairie, has reduced the mean temperature in July by two degrees Celsius. Transpiration by plants seems to cool the air and produce clouds over the plains. Further irrigation, then, may enhance the effect, for the plains’ winds will cool the nearby mountains, and that will increase rainfall there.[6] Some may wish to draw the conclusion that the global problem of climatic change will thus resolve itself into a collection of regional problems. It seems to me, however, that the wisest approach is to determine how regional climates interact with the global climate. Just to parade a trivial example: We would not want to increase irrigation in dry Southern California in a year when a strong El Niño is bound to dump near-disastrous amounts of rain on the region.

We may not wish to postpone action until the pessimists’ computer models place the catastrophe beyond doubt. We may find a reasonable compromise by searching for a better global understanding of our planet (and of the problem of CO₂ in that context).[7] Even if the dissenters are right and global warming turns out to be a false alarm, sleeping free of worry will not be the only benefit to derive from that search. Our new views will improve our dealing with the Earth in a myriad of ways.

Eventually the story will likely be resolved by space technology used in combination with fields like oceanography and paleobiology. The idea behind the “Mission to Earth,” for example, was precisely to look at Earth from space the way we have looked at other planets. This most ambitious mission evolved into the somewhat more modest Earth Observing System, a multi-billion dollar, interdisciplinary effort to understand global climate by observing the Earth from space. The three main instrument platforms are called Terra, Aqua and Aura (to study, respectively, land, water, and atmosphere). It is clear to many scientists that even this effort must be surpassed. A recent meeting of the National Research Council attempted “to do for climate change what has been done for astronomy, planetary science, and solar physics: create consensus on a realistic, long-term blueprint for the field, including the most important questions to be answered and the tools needed to explore them.”[8]

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[1]. According to Benford, it would take a land the size of Australia covered with trees to soak up all the present increase in CO_2. “Climate Controls,” Reason, Vol. 29, No. 6, November 1997, pp. 24-31.

[2]. Ibid., p. 27.

[3]. William McKibben, The End of Nature,

[4]. op. cit.

[5] P.G. Falkowski, Scientific American, op. cit., p. 61.

[6]. Jennifer Couzin, “Landscape Changes Make Regional Climate Run Hot and Cold,” Science, Vol. 283, 15 January 1999, pp. 317-319.

[7]. This will, of course, make for improved climatic computer models.

[8] Andrew Lawler, “Stormy Forecast for Climate Science,” Science, Vol. 305, August 20, p. 1094. Unfortunately, I fear, the needed effort may be undermined by the political advocacy by scientists during the past several years. According to this article, “Whereas fiscal conservatives would attack any massive new research program as unaffordable, liberals are likely to see it as a ruse to delay action on the underlying problems that are causing global warming.” P. 1097.

Musings 2

Chapter 4D

Musings 2

Nevertheless it follows from Lovelock’s considerations that life influences to a large extent the climate of the planet. Life largely determines chemical composition, and chemical composition largely determines the range of many crucial physical factors such as freezing and boiling points, which in turn determine whether several substances will be in gaseous, liquid, or solid form. In the deep cold of Titan, the large moon of Saturn, there are large lakes, because the dense atmosphere, mostly nitrogen, contains 1% methane, and methane can exist as a liquid at those pressures and temperatures.[1] Those physical factors will also affect the patterns of heating (e.g., the greenhouse effect) and cooling (e.g., glaciation), and thus the transfer of energy throughout the system. It is not surprising, then, that by removing gases from the atmosphere, or by replenishing them, life on Earth exerts much influence upon the climate.

Stephen H. Schneider criticizes the notion of Gaia as a regulating mechanism, a sort of giant planetary thermostat, by drawing attention to the fact that on occasion life gives a positive feedback to the climatic changes taking place. He assumes too narrow an interpretation of Lovelock’s idea, however, for Gaia is a metaphor not merely for life on Earth, but for the whole interaction of life and the rest of the environment. Some parts of the total environment may thus temporarily accelerate climatic changes, as we have seen, but at some point other parts of the system bring about stability and often reversal. Had it not been that way so far, life would have disappeared from Earth long ago.

Still, the most Lovelock can conclude is that life on this planet is very resilient. But after this point is acknowledged, we still have much reason for concern. For example, he points out that the present industrial pollution of the planet cannot compare with the massive poisoning of the atmosphere by oxygen a billion years ago. When the free hydrogen in the atmosphere had been used up or escaped into space, bacteria began to withdraw it from H₂O in photosynthesis. The waste product, oxygen, was extremely toxic to most of the bacteria that dominated the Earth in those days.[2] Sure enough, life overcame this threat by developing organisms that used oxygen. But we should find no comfort in learning that those evolutionary solutions led to the replacement of one kind of life by another. If we foul up our own planet, life may survive – but we might not. Industrial waste fertilizes the water in our lakes and rivers and leads to the rapid growth of algae. This kills the fish, the frogs, and the water lilies. It is not much consolation to know that upon the ruins of the present order life will adapt and produce a new kingdom of scum.

The pessimists urge us to think about the Earth in the long run, and particularly about the drastic changes that we may bring about in the next few centuries because of our use of fossil fuels. But we may also wish to put their own concerns in the context of the truly long-run, not just centuries, but thousands of years, and then tens and hundreds of millions of years.

For the past 400,000 years, according to the temperature record found in deep ice in Antarctica, our planet has been going through glacial cycles of about 90,000 years, punctuated by short warm interglacial periods (about 11,000 years each). Indeed, our planet has been very cold for the last 2.5 million years and is likely to remain so for the next 2-10 million. As Peter D. Ward and Donald Brownlee point out in their book The Life and Death of Planet Earth, the present interglacial period has been unusually long already.[3] This prolonged period of warm may be accounted for by Milutin Milankovich’s theory of the influence of Earth’s orbit on its climate (to be discussed later in the chapter). But according to some calculations, the present warm period will give way to another glaciation in a few thousand years at most.[4] The temperature record shows, however, that the switch from warm to ice can take place almost suddenly, so we may be due for another “ice age” at any time. Of course, the descent of sheets of ice two miles high upon the Northern hemisphere would devastate our present civilization far more than the current warming of the atmosphere is likely to. Ironically, the much-maligned man-made global warming may stave off the ice for another 50,000 years![5]

In the truly long run, but long before the sun becomes a red giant, the Earth’s thermostat is likely to malfunction. It was Lovelock himself who realized that Gaia would eventually fail as the planet’s self-regulatory mechanism. In a 1982 article with M. Whitfield, he argued that life was steadily removing CO₂ from the atmosphere – it actually has been doing so for the last 400 million years, when plants conquered the land – and in about 100 million years the level of CO₂ will go below 150 parts per million (ppm)of air.[6] This level is important because most plants require at least that much atmospheric CO₂ to survive. Newer forms of plants – grass, palm trees – use slightly different mechanisms for photosynthesis and can go well below the 150 ppm. The flora of the future, then, will have a very different view: gone will be the apple orchards and the rose gardens, replaced by new and exotic varieties of plants. But, eventually, the level of atmospheric CO₂ will go below 10 ppm and photosynthesis will come to an end altogether. More recent studies following on Lovelock and Whitfield’s footsteps have revised their estimate to between 500 million and a billion years.[7]

The loss of plants will be a catastrophe for animals, obviously, but also for marine life, since it depends so much on the run-off of the soil nutrients that result from the presence of plants. Those few animals that can manage to survive will be obliterated in a few million years by the rising temperatures, for eventually significant levels of atmospheric CO₂ will rise in the atmosphere by geological processes but will no longer be kept in check by photosynthetic organisms. Several scenarios have been proposed to explain what will happen after that point. To me it seems simple to imagine that a highly increased level of solar energy coupled with high levels of atmospheric CO₂ will quickly lead to the sort of runaway greenhouse effect that vaporized Venus’ oceans.

It is possible, nonetheless, that Lovelock and those who refined his prediction of doom have not given Gaia enough credit. After all, just as cyanobacteria were able to survive in small, protected pockets the flooding of the planet by oxygen, a few plants may just barely survive near vents that outgas CO₂, lie low until the CO₂ rises again, and then explode once more through ocean and land. Other photosynthetic life on land and in the ocean will thrive also, as their ancestors now do, and together with the plants will begin to regulate the climate and, literally, give the Earth a new lease on life.

Of course, this new, though not improved, version of the planetary thermostat gives even less reassurance than the previous one. Indeed, it turns out that the thermostat has allowed the entire planet to become a ball of ice once or twice in the eons before the Cambrian explosion.[8] We cannot escape the need to reach a better understanding of our global environment.

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[1]. Methane on Titan would thus be the counterpart of water on Earth. Other possible counterparts, in other planets, would be ammonia, which freezes at -78 degrees Celsius and boils at -33 degrees Celsius, and methyl alcohol, whose range is from -94 to +65 degrees Celsius.

[2]. Adapted from L. Margulis and D. Sagan, Microcosmos, Summit Books, New York, 1986, p. 237.

[3] Ward and Brownlee, op. cit., pp. 71-86.

[4] R. Chris Wilson, Stephen Drury, and Jenny L. Chapman, The Great Ice Age, 2000. Cited by Ward and Brownlee, p. 82.

[5] Ward and Brownlee, op. cit., p. 83. On the other hand, global warming, according to some speculations, might trigger the ice age by shutting off the water circulation patterns in the Atlantic (warm water going north closer to the surface and cold water going south closer to the bottom of the ocean).

[6] J.E. Lovelock and M. Whitfield. 1982. “Life Span of the Biosphere.” Nature 296. Pp. 561-563.

[7] This account is borrowed from Ward and Brownlee, op. cit., pp. 101-116.

[8] Ward and Brownlee, op. cit., p. 75.

Zubrin

Last week I attended a convention of the International Mars Society and had an opportunity to exchange some ideas with Robert Zubrin. A few weeks ago I had expressed the thought that, given the startling space budget proposed by the Obama administration, and particularly the ending of the Constellation Program that would have returned us to the Moon, it would take imaginative thinkers like Zubrin to come up with strategies that would permit us to make a silk purse out of a sow's ear. I suggested then that perhaps going with a modular construction of space ships would permit us to get around the lack of the heavy-lift booster canceled by the administration. But Zubrin himself would have none of it, as he made quite clear to me. He thinks that a heavy-lift booster is essential. Once we have a booster in the class of the Saturn V again, we will be in a position to put an outpost on Mars. He insisted that modular technology has not been successful so far, and that there is no point in trying to reinvent the wheel when we already have the know-how to get the job of manned exploration done, the exploration of Mars included. His solution is to put political pressure on the House of Representatives to approve the space budget already approved by the Senate, which restores the heavy-lift booster and other capabilities we need to go to Mars. He would rather skip the Moon and go straight to Mars, but is willing to put up with the Moon delay as long as we are back to the technology level of the Apollo era. We could have been on Mars by 1985 or even earlier if we had kept up Kennedy's example of setting up ambitious missions and going all out to meet those goals. Indeed, for all the money, time and energy we have wasted on the Shuttle and the International Space Station, we could have thriving outposts on both the Moon and Mars by now. More on all this in a few weeks.