Friday 29 May 2009

Global Warming and SF – Part 3

This is the third and last part of my tour around the global warming issues and what might be done about them, with a view to how these might feature in SF. Last time I identified four possible courses of action: to cut back CO2 production; to remove CO2 already in the atmosphere; to reduce insolation (heat received from the sun); and finally to adapt to the changes which are now inevitable. I have already dealt with the first one, now for the other three.

Remove CO2 already in the atmosphere

One of the major problems with churning out CO2 is that, once in the atmosphere, it persists for a very long time. This contrasts with other greenhouse gases such as methane, which disappear relatively quickly. Even if it were possible to stop all burning of fossil fuels immediately, the quantity of CO2 already in the atmosphere would remain higher than pre-industrial levels for centuries to come; which means that the Earth will continue warming up for centuries. As a result, there is increasing interest in "geoengineering" – physically removing CO2 from the atmosphere, or finding other ways to increase CO2 absorption or to prevent the greenhouse effect.

Geoengineering is highly controversial because of worries that it may have unwanted consequences; for instance, increasing oceanic absorption of CO2 will increase seawater's acidity (something which is already beginning to happen) with potentially dire consequences for the marine ecosystem. It is therefore only being considered as a last resort, because climate scientists now believe that there is no chance of cutting CO2 production by enough to make much difference; in fact, before the current recession hit, carbon emissions were still increasing by 3% a year.

Geoengineering techniques can be as simple as planting trees, but this only postpones the problem – at some point, the trees will die and their carbon will be released. More drastic measures are therefore being considered. These include seeding the oceans with iron filings to encourage the growth of organisms which would trap CO2. However, apart from the acidification problem, a recent experiment failed to achieve the desired effect.

A more high-tech approach is to manufacture huge quantities of "scrubbers" which will physically remove CO2 from the atmosphere. Three different techniques have been proposed.

One is a "spray hangar" in which air is sucked in one end and blown out of the other after being sprayed with sodium hydroxide solution; this reacts with CO2 to form droplets of sodium carbonate. This is known to work, but in its present form requires a huge amount of energy.

An alternative is the "solar scrubber", using sun-focusing mirrors to heat a transparent tube filled with pellets of calcium oxide. As the temperature rises to 400 degrees C, air is blown through the tube and its CO2 combines with the chemical to form calcium carbonate; virtually all of the CO2 is extracted. The process can be reversed by doubling the temperature in order to drive off pure CO2 which can easily be captured; but of course, a safe way of disposing of it then has to be found. One possibility is to pump it into adjacent greenhouses in order to promote crop growth (a technique which is already being used).

The third option is the "air collector", which pumps air over an ion exchange resin, a polymer impregnated with sodium hydroxide, to which the CO2 adheres. It can later be washed out for disposal using humid air at only 40 degree C.

The benefit of these technologies is that there appears to be minimal risk of unintended consequences since all they do is extract CO2, a process which can instantly be switched off when no longer needed. The main drawback of the CO2 scrubbers is that millions of the things would be needed, at huge cost.

Reduce insolation

A different approach is to reduce the degree by which the sun heats up the Earth, by reflecting more of its rays back into space. As we have seen, ice fields reflect around 90% of the insolation (compared with 94% absorption in open water) and their melting is contributing to Arctic warming. One study calculated that reflecting an extra 1.8% of insolation would cancel out the effects of doubling the CO2 levels.

Various fanciful ideas have been proposed, such as dumping vast quantities of white polystyrene to float in the oceans (which could of course reduce their capacity to absorb CO2) or pumping sulphate particles high into the atmosphere to reflect the sun's rays (but this could cause catastrophic droughts in some regions, and would need constant renewal). A variation on the last one is to pump atomised seawater into stratocumulus clouds in order to increase their density and make them more reflective. This should work, but the processes of atomisation and of getting the water up to the clouds in such enormous quantities are obviously not trivial issues.

A more high-tech approach is to launch "sunshades" into space, in the form of discs of silicon about 60 cm across., just a few micrometers thick and weighting 1 gram. Each would be covered with holes calculated to act like a lens, causing dispersion and dimming of the sunlight. They would be "steerable" using solar energy to keep them in the correct position and orientation. The proposal involves launching containers, each carrying a million discs, from huge electromagnetic rail guns, towards the L1 Lagrange point where the Earth's and the sun's gravities cancel out. It has been estimated that twenty rail guns, each 3 km high and working around the clock to launch one container every five minutes for ten years, could achieve the 1.8% reduction, and it is hoped that the discs could last for up to 50 years.

The danger with all of these techniques would be if they were relied on to cancel out the effect of rising CO2 levels, thereby allowing CO2 to build up to high levels. Should the regular renewal of the sunshades then fail for any reason, the consequences to the climate of being suddenly exposed to high levels of atmospheric CO2 could be sudden and catastrophic.

A lower-tech approach would be to install reflective surfaces on the roofs of buildings or in the form of material covering desert areas, in those locations not required for solar heating or power systems.

Adapt to the changes

It is now accepted by climate scientists that any effective moves to reduce CO2 production will now be too late to avoid some unpleasant consequences – our politicians have already failed us by avoiding the potentially unpopular measures required. Even the 2007 IPCC report predicted a rise in global average temperature of between 2 and 6.4 degrees C this century and, as we have seen, a recent conference of climate scientists concluded that the outlook has worsened since that was written. An increase of 4 degrees by the end of the century now looks quite possible on present trends. So as well as continuing to try to minimise the warming effect, we are going to have to prepare for the consequences of a warmer world.

What this might mean is discussed in an article published in New Scientist on 28 February 2009 ("Surviving in a Warmer World"), which spells out the implications of a 4 degree warmer world. The picture painted is frankly horrifying. Much of the tropics would become uninhabitable due to drought, floods or extreme weather; the Amazon basin would become a desert, as would most of the USA, southern Europe, nearly all of Africa, southern Asia and Australia. Rising sea levels would mean that low-lying areas would vanish. On the bright side, there would be some potential for reforestation due to changing wind patterns, in west Africa and western Australia. However, the main areas suitable for habitation and farming would be Canada and Alaska, northern Europe and Asia, New Zealand, western Greenland and western Antarctica. These would become exceedingly crowded places, with the surviving population having to live in dense, high-rise accommodation to leave as much usable land as possible free for agriculture.

James Lovelock, who developed the "Gaia" theory, estimates that the devastation caused by climate change could result in the world's population reducing to 1 billion or less by the end of this century. Inevitably, there would be huge conflicts as displaced populations attempted to move to more favoured areas. Many observers think that the first climate change war has been underway for years, in the civil war in the Sudan. Christians and Muslims had lived peacefully side-by side in Sudan's Darfur province for centuries, but the trigger for their vicious war (in which 200,000 have already died and around two million been displaced) has been a dramatic reduction in rainfall over the past few decades, leading to increasing desertification and a conflict over the remaining usable land. If the regional climate projections are right, similar problems are likely to occur throughout the tropics during this century.

Other climate impact specialists consider that the worst consequences can be reduced, provided that we start planning and acting now, by determinedly adopting the kind of measures discussed in this survey. It's too late to prevent a lot of problems, but it's worth doing all we can to minimise the future scale of them, since that could prevent a bad situation from becoming utterly appalling. The political issues and pressures generated by all this are a potential source of material for near-future fiction.

Even if world leaders really begin to address this problem effectively, some changes will have to be made. The rising sea level, combined with more, and more violent, storms means that it would generally be futile to continue defending low-lying coastal areas. To give one well-known example, there is no point in the long term in trying to protect cities like New Orleans. This is already beginning to happen in a small way, with the evacuation of the 1,400 inhabitants of Papua New Guinea's Carteret Islands, and there are similar plans to abandon other low-lying oceanic islands. The prospect of millions of Bangladeshis moving into India as their land floods will raise problems on a very different scale.

Water shortages resulting from a combination of climate change and population growth will also require some changes to farming to get the maximum value out of agricultural land. One consequence is that meat-eating will have to diminish because, for the same food value, animal farms use farmland and water at several times the rate of crop farms. So the only farm animals likely to survive will be those which can live on rough mountain pasture unsuitable for agriculture. To make matters worse, fish stocks will continue to shrink, not just through overfishing but through the increasing acidification and deoxygenation of the oceans. The water shortages will almost certainly end the current squeamishness about genetically-modified crops; to produce enough food, it will be necessary to develop drought-resistant strains.

Even so, a switch to a largely vegetarian diet wouldn't provide a complete solution. Crops not only use up a lot of water, our commercial farms are also heavily dependent on oil, for farm machinery, transport and fertiliser. Reductions in the use of fossil fuels to cut back on CO2 production, combined with an increasing shortage of oil as cheap sources are used up, will make traditional crop-growing far more difficult and expensive. A recent UK TV programme on "farms of the future" predicted the decline of large-scale crop growing in favour of local "vertical farms", based on hedges and trees producing fruit, nuts and edible leaves, which can provide several times the food value of the same area of arable land. These require very little work or other resources to grow, but they are much more labour-intensive to collect.

That just about wraps up my survey. In a nutshell, climate change is accelerating, and if we wish to avoid some rather horrendous consequences, we need to put a far higher priority on taking the kind of preventative and precautionary measures I have been describing. I hope that all of this provides some useful material for the SF community; certainly there is scope for a wide range of backgrounds, from best-case to worst-case. My own novel, which I mentioned last time, was intended to represent a likely future but, in the light of the latest information, is now looking to be at the optimistic end of the spectrum!

Friday 22 May 2009

The Time Machine by H G Wells

I surely must have read this at some point in my youth, but I can't recall it. All I can remember is watching the 1960 film version and that memory only involves Yvette Mimieux in a starring role, which gives a clear idea of adolescent priorities. So it was with some interest that I read this prior to discussing it with the Classic SF group.

H G Wells (1866-1946) was of course one of the pioneers of modern science fiction, writing such classic works as The War of the Worlds (invasion from Mars), The War in the Air (foreseeing aerial warfare – in 1908), The Invisible Man, The First Men in the Moon and The Shape of Things to Come. He also forecast – and named – the atomic bomb in 1914, in The World Set Free.

The Time Machine was Wells' first novel, published in 1895, and made his reputation. It is narrated by an unnamed guest at a Victorian dinner party given by a man identified only as the Time Traveller, and consists of the Time Traveller's account to his guests of a journey to the future from which he had just returned.

The story was controversial on publication because its principal theme was that mankind would evolve. Since resistance on the part of fundamentalist religious groups to the idea of evolution in general, and human evolution in particular, still exists even today, their condemnation is not surprising. What must have been even worse to many people is that Wells showed a humanity which had devolved into two degenerate races: the small and beautiful but unintelligent Eloi, who lived an apparently idyllic existence on the surface of a garden-like world, and the hideous and evil subterranean Morlocks. The novel, or more precisely novella since it is only 80 pages long, principally deals with the Time Traveller's stay with the Eloi and his encounters with the Morlocks.

A particularly interesting suggestion in the story, also obviously prompted by Darwin's theories, was that the decline of humanity had occurred because civilisation had become too successful; the upper classes lived such idyllic lives that the evolutionary pressures which had sparked the development of intelligence had disappeared. The lower classes, slaving away in the darkness, had similarly become adapted to their environment. In the world of the Eloi and the Morlocks, the ruins of an obviously glorious past (still in our future) were still scattered across the landscape.

Leaving the world of the Eloi behind, the Time Traveller rushes into the far future. He stops only when the sun has become a vast, dim and stationary red ball in the sky. All is silent, with just a few creatures scavenging a living in the thin air of a cold and almost dead world. For me, these brief images carry more evocative power than the rest of the story.

The themes of The Time Machine are as relevant today as they were then; the style of the story-telling has changed a lot, but the ideas still resonate. The impact which they had on a Victorian world largely unexposed to science fiction can be imagined. About the only anachronism is the short timescale, which only reflects the lack of knowledge when the story was written. The Eloi and the Morlocks are said to live just over 800,000 years in the future, the end of the world in only 30 million years. Compared with modern works there is also a total lack of characterisation, but that doesn't really matter here – this was a novel of ideas.

H G Wells is one of the few novelists whose work reached beyond its powerful influence on the genre, extending to a genuine impact on ideas in wider society. He also did more than write fiction; for the latter part of his life he became what would be known today as a futurist, concentrating on writing forward-looking works such as The New World Order and The Future of Man. Much of his later fiction also departed from SF, focusing more on society as in The History of Mr Polly, which I recall having to study in school.

The Everyman edition of The Time Machine which I have contains a lot of related material, including a chronology of Wells' life, a 23-page introduction to the story, comments on the text (plus an additional section which was omitted from the published novel) and the varied critical assessments of the work. Useful additions which add to the appreciation of one of the most famous SF novels ever written.

Friday 15 May 2009

Fiction bonanza from the BSFA!

The British Science Fiction Association doesn't usually publish fiction (unlike the other major UK SFF organisation, the British Fantasy Society); its periodicals contain reviews, analyses and other articles. So it was a surprise to find that their most recent postings contained three short-story collections. One consists of the four stories on the shortlist for the BSFA Short Fiction Award for 2008. The next is a special edition of their normally non-fiction "magazine for writers", Focus, which this time contains the six shortlisted stories specially written for a competition to mark the 50th anniversary of the BSFA. The third is a sampler edition of Postscripts, "The A to Z of Fantastic Fiction" (from, with stories from previous editions.

BSFA Awards 2008: short fiction shortlist

Two of the four stories I had already read and reviewed, since they originally appeared in Interzone magazine. These are Crystal Nights by Greg Egan (Interzone 215) and Little Lost Robot by Paul McAuley (Interzone 217). To save you from rummaging through the history of this blog, I'll reproduce what I said here:

Crystal Nights, by Greg Egan: One of the world's richest men is paying the best programmers to evolve artificial intelligence by developing initially simple virtual beings then applying a carefully controlled process of natural selection. With the aid of a new generation of superfast computers, the evolutionary process is extremely quick and soon the AIs are beginning to outstrip their human creators, with unexpected results.

Little Lost Robot, by Paul McAuley: A different take on Saberhagen's Berserker series, this time seen from the viewpoint of an ancient but still all-powerful robotic killer spaceship. Problems arise when the ship detects signs of life in a system which seems strangely familiar.

The other two stories are:

Exhalation, by Ted Chiang (first published in Eclipse 2): Set in an enclosed, robotic civilisation with no knowledge of other forms of life. The narrator, one of the robots, conducts experiments into his own nature and functioning, concluding (in an amusing take on creationist notions) that there must have been an "Intelligent Designer", and predicts the end of their existence.

Evidence of Love in a Case of Abandonment: One Daughter's Personal Account, by M. Rickert (first published in The Magazine of Fantasy and Science Fiction, October/November 2008): A dystopian future set in a society governed by religious fundamentalism, where women found guilty of having abortions are publicly executed.

The pick of the bunch for me was Ted Chiang's story, very strong in the "sense of strange" gained from letting a denizen of an alien environment describe his life in a very matter-of-fact way.

Next, the stories in Focus, starting with the winner of the competition (the others are in alphabetical order).

Nestbuster by Roderick Gladwish

A doctor visits a man called Abraham and his family on a remote farm on a distant planet, to carry out some tests. It gradually emerges that Abraham is a former "nestbuster" – a soldier with highly enhanced capabilities to fight a war with aliens. These soldiers had been successful in winning the war but very few had survived, most committing suicide if they weren't killed in battle. The doctor wants to know why Abraham is still alive, but it turns out that he has another agenda altogether – and that Abraham has a secret.

Time's Chariot by Nina Allen

An intense relationship between a brother and sister living in a strange family, well described but not obviously SF.

Surf Town by James Bloomer

The Mesh Surf Pro Tour is arriving in town, using advanced technology to whip up the sea into waves to challenge any surfer. One resident, a former surfing champion who left the circuit when the artificial wave generators were introduced, is not pleased to see them. He has no intention of being drawn into the circus, but…
This is seemingly an alternative history story, since the champion surfer is called Bodie Miller, presumably a reference to the current US skier Bode Miller, one of the most successful competitors in recent winter sports championships.

The Mark by Nigel Envarli Crowe

The separate but intertwined stories of three women, related but of different generations, commencing with a Chernobyl nuclear accident and showing the long-term consequences for humanity.

Maria Via Lilly by Gary Spencer

A future world in which the dying can be scanned to generate a virtual copy (including the personality) which can be viewed on-screen, living in the environment created by the recorded memory. But what happens if the copy is stolen and duplicated for others to enjoy?

Rescue Stories by Andrew West

A space-ship crashes on a stone-age world, far from any chance of rescue. The crew can last for a long time in hibernation waiting for the natives to develop sufficiently advanced technology to help them, but only if the crew intervene to speed up the natives' development, which proves to have a drawback…. It brings to mind a similar story, although the ending is different.

On to Postscripts. This contains ten previously-published stories from Stephen Baxter (Eagle Song – the consequences of receiving a transmission from the stars), Ray Bradbury (Juggernaut – the hazards of moving house), Ramsay Campbell (Direct Line – a modern horror story), Peter F Hamilton (Footvote – the consequences of a wormhole providing access to another habitable world being opened in England), Joe Hill (Best New Horror), Stephen King (Graduation Afternoon – a horrifying image of what might happen), Paul MacAuley (The Thought War – zombies with a difference), Lisa Tuttle (Closet Dreams – more contemporary horror, without any fantastic elements), Gene Wolfe (Comber – life on a floating city), and Al Robertson (Sohoitis – a god lives in Soho). The emphasis is too much on horror for my taste, but an interesting read nonetheless.

Friday 8 May 2009

Where is Everybody? Fifty solutions to the Fermi Paradox, by Stephen Webb

The Fermi paradox is named after the mid-twentieth century physicist who posed a simple question: calculations based on reasonable estimates indicate that this galaxy should host a large number of extraterrestrial civilisations capable of interstellar communication or travel (which Webb shortens to ETCs), yet we have so far been unable to find any evidence for the existence of even one such civilisation. So where are they all?

The astronomer Drake later quantified the calculation like this: the number of ETCs in the galaxy (N) is determined by the rate at which stars form (R), the fraction of stars with planets (fp), the number of those planets with an environment suitable for life (ne), the fraction of those planets on which life actually develops (f1), the fraction of those which produce intelligent life (fi), the fraction of those which develop a civilisation capable of interstellar communications (fc), and finally the number of years that such a culture will devote to communication (L). The "Drake equation" therefore reads N=(R)x(fp)x(ne)x(f1)x(fi)x(fc)x(L). This looks impressively authoritative, but a moment's thought reveals that we have no means of knowing most of the factors, so figures which we enter for them are little better than guesswork. And the calculated number of ETCs will vary greatly depending on the particular guesses we make. Another point is that should any of the factors be zero, then the outcome will also be zero. Despite this, calculations of star formation rates for this galaxy result in N being a very large number even with pessimistic assumptions being made about the other factors. In other words, this galaxy should have been swarming with ETCs for millions of years, which we could hardly have failed to notice.

Having discussed this paradox, the author then briefly describes and evaluates a select fifty (there have been many more) explanations put forward to account for this interstellar silence, before revealing his own solution. As the reviewer, I will of course conclude by proposing a slightly different answer! Webb divides up the explanations into three broad categories: "They are here"; "They exist but have not yet communicated"; and "They do not exist". I'll take each of these in turn; I obviously can't do justice to a book full of ideas in a blog, so I'll just pick a few examples.

They Are Here

This group contains only eight explanations, ranging from the amusing (they exist and are meddling in human affairs), through the paranoid (we have been isolated by the galactic civilisation, or we live in a simulation), to the more serious (panspermia: we are all aliens, because life was kicked off by being seeded from outer space) and finally the religious (God created this universe only for us; any other ETCs have their own universes created for them).

Webb clearly doesn't rate any of these very highly. The most feasible, panspermia, doesn't actually solve the problem, since if our planet was seeded so presumably was every other suitable one – so where are they all?

They Exist But Have Not Yet Communicated

More than twenty explanations here, some of which argue that ETCs may for various reasons not be interested in travelling to, or even communicating with, other civilisations. Just because we are explorers doesn't mean that everyone else has to be. However, Webb points out that it only takes one with the same urges as we have to reach out to other worlds, and potentially spread throughout the galaxy.

Other explanations are therefore more practical, focusing on the difficulty of interstellar communication – let alone interstellar travel. The popular belief that ETCs in our neighbourhood would have detected us now via our routine radio and TV broadcasts is shot down; it appears that these would fade out before they could reach even the nearest star. Even a focused radio beam aimed at another star would be hard to detect; lasers are more promising, but a nearby ETC would have to exist now, and be beaming a signal directly at us, and we would have to be looking in the right place at the right time to notice it. Another idea is that they are signalling but we're not picking it up, for various reasons; or we have picked it up, but haven't properly analysed the data. Or possibly ETCs don't spend long in an active signalling phase before they upload themselves into computers or some higher non-material plane to enjoy the unlimited pleasures of virtual reality.

The difficulties of interstellar travel are well rehearsed, since there are no indications that Faster-Than-Light (FTL) spaceships will ever be possible and frozen sleep or generation ships have their own major problems. Bracewell-Von Neumann probes (which are sent to other star systems to mine their resources and then replicate themselves to send out to more systems) would be one way of spreading an inanimate presence throughout the galaxy quite quickly. The fact that we have not detected such probes is therefore a puzzle. Somebody should have got around to doing it.

They Do Not Exist

Webb lists almost as many ideas under this heading, which to me represents the most interesting part because it is more solidly based in science rather than speculations about alien psychologies or the like. These explanations look at the sequence of improbable events which has led to our civilisation and argue that this sequence may be unique.

There are several elements to this: first that the galaxy is a dangerous place, regularly blasted by intense bursts of gamma radiation from supernovae which would affect life for thirty light years around. The outer galactic zone in which the Solar System sits may be in the "Galactic Habitable Zone" (GHZ), a less vulnerable position than the more crowded central zone. The mysterious Gamma Ray Bursters (GRBs) are even more devastating; they could affect an entire galaxy and reset the evolution clock each time (for obvious reasons, they have so far only been observed in other galaxies). It is estimated that a GRB could happen in a galaxy like ours about every hundred million years, which would approximately match the frequency of mass extinction events on Earth. So maybe we are among the first to achieve a technological civilisation since the last GRB wiped out any previous ones.

The next point is that planetary systems are inherently dangerous. Catastrophic events such as asteroid strikes, supervolcanoes like Toba or other causes of wild fluctuations in the global climate may have led to many mass extinctions even without the help of GRBs or supernovae. Life may also require very particular circumstances in which to develop intelligence: obviously, any life like ours needs liquid water to be available for hundreds of millions of years, which means that the planet must be in exactly the right circular orbit (the continuously habitable zone, or CHZ) to achieve this even through various fluctuations in the sun's output. Finally, the tidal effects of one large moon plus the constant crustal renewal of plate tectonics may also be important elements in the conditions which led to us, although that is more speculative.

Then we come on to the biological improbabilities. A key one identified by Webb is the development of multi-cellular eukaryotic life, compared with much simpler prokaryotic life such as bacteria. This was a remarkable event which took billions of years to happen – possibly, it's uncommon. So might be the development of intelligence at our level. Perhaps most significantly, of all of Earth life, we are the only one to develop the sophisticated language without which our civilisation could never have arisen, so this may be a very rare feat. And we cannot assume that every intelligent civilisation will be a technological one.

The Author's Solution

Webb makes clear at the beginning that in assessing the probabilities of ETCs developing, he is looking only at life "as we know it, Jim": based on carbon and liquid water. He acknowledges that there may be other forms of life, but since we know nothing about this, there is no basis even for speculating what it might be capable of. Anyway, that doesn't affect the basic problem that we have detected no indications of any forms of life.

Webb's conclusion, based on the arguments raised in the last section, is that we can't detect any ETCs because there aren't any – at least in our galaxy. (There are estimated to be hundreds of billions of galaxies in the universe, but the difficulties of communication and travel escalate by orders of magnitude if we try to include them; our own galaxy is big enough to grapple with!)

His view is that our complete failure to identify any signs of life elsewhere, when all the logic of Fermi's paradox suggests that there should be countless ETCs out there, probably with successive waves of expansion affecting the Earth, has only one feasible explanation – that we are alone. He works through several steps to justify this. First, he estimates that star systems in the galactic habitable zone make up only about 20% of those in the galaxy. Next, stars like our sun are needed to develop life as we know it; they make up only about 5% of the total. So we are down to only 1% of stars being suitable. Thirdly, a terrestrial planet needs to remain in an orbit within the continuously habitable zone for billions of years. He guesstimates that applies to perhaps only 0.1% of all planets (assuming 10 planets per star, that's 1% of the suitable stars). We are now down to about ten million such planets in our galaxy.

Now we switch from the potential for life to its actuality. How many of these ten million will support life? Webb guesstimates maybe half a million, of which 20% might suffer catastrophic extinctions; now we have 400,000. Factor in the number on which life progresses to the complex multicellular eukaryotic stage – he suggests one in forty – and we're down to 10,000. Then apply factors for tool use, high-level intelligence and complex language – and Webb believes we're left with just one; us.

Your Reviewer's Conclusion

Webb puts forward a well-reasoned case to explain why we might have the only technological civilisation in the galaxy. However, I still find his conclusion improbable. Obviously, this is purely a matter of subjective opinion – emotional prejudice, if you wish – as there is no hard evidence one way or the other. It is just that faced with the early development of life on Earth and its tenacity in colonising every possible environmental niche and developing a myriad forms of increasing complexity, I find it impossible to accept that, among the billions of star systems, we might be in the only one to have produced a technological civilisation.

My conclusion goes part-way with Webb, in that I think that while life may be very common, complex animal life may be very much less so; beings intelligent enough to develop technology far less still; and the actual development of a technological civilisation extremely rare. Just look at the history of our planet; simple monocellular life seems to have occurred quite early, perhaps less than a billion years after Earth's formation. But the oldest evidence for complex animals comes almost three billion years later. These rapidly developed to dinosaur levels of complexity, but then stagnated for hundreds of millions of years. Finally, through sheer luck, humanity evolved, but the earliest hominims were around for several million years before modern humans arrived about 200,000 years ago; and for 95% of those 200,000 years, our ancestors did nothing but live in hunter-gatherer packs, like clever animals. Our technological civilisation is the result of a long series of improbable accidents.

As a result of studying Webb's arguments, I am more pessimistic than I used to be about the chances of other ETCs developing. However, given that there are calculated to be 100 billion stars in our galaxy (that's 100,000,000,000), even if our planet was literally "one in a million" in producing a technological civilisation, that still works out as 100,000 ETCs. So where are they? The answer I favour is "not here now". Two different timescales need to be borne in mind: the age of the galaxy, and the probable lifespan of an ETC. Our own star is around 4.5 billion years old, compared with the average for our galaxy of 6.5 billion years (the oldest star being over 13 billion). So if we assume that it takes 4.5 billion years after star formation to produce a technological civilisation (the only example we've got), that means that other stars average a two billion year advantage over us – lots of time to produce a huge range of ETCs. But how long can these ETCs be expected to last?

Just consider our situation again. We achieved the theoretical capability to communicate with other star systems only within the last century. Only half a century after that, we came dangerously close to wiping out our civilisation in a global thermonuclear war. Many scientists fear that over the next century or two we will have devastated our global environment to such a degree that our civilisation will collapse, giving us only a few centuries of possessing advanced technology. By definition, any civilisation with the technology capable of communicating with ETCs will develop the potential to destroy itself, one way or another. So perhaps ETCs just don't last very long. Suppose that the average is 1,000 years; multiply that by the nominal 100,000 ETCs mentioned above, and you get a total of 100 million "ETC years". Compare that with the 2 billion year average time advantage the galaxy's stars have over our sun, and you will see that an ETC will have been in existence for only about five percent of the last two billion years. So at any given moment there may be only a one-in-twenty chance of a single ETC existing anywhere in this galaxy. And no ETC would have the time to spread very far even if it wanted to; possibly none would ever manage to establish itself on another star system.

This is, of course, speculation built on speculation, but with a grand total to date of just one known example of a life-bearing planet to go on, that is bound to be the case. My vision is this: imagine if a camera could have been sited over our galaxy, filming continuously for the last few billion years, and recording each ETC as a bright flash. Then replay the film in quick time. I think we would see a huge number of ETCs sparkling all over the galaxy, from two billion years ago to the present. But slow the film down, and we may see only one flash at a time, with long pauses between them. Occasionally we might see two or more flashes occurring simultaneously, but on average they would be so far apart that communication between them would be highly improbable.

Webb didn't mention the Gamma Ray Burster problem in his conclusion, but if our galaxy is blasted by one every hundred million years or so, clearly many of the above calculations become rather academic. That could explain the silence all by itself.

And another thing…

A further point may limit the number of ETCs likely to be in existence at any one time. If an ETC is established on a planet and fails, for any of the reasons mentioned above, it may prove to be the one and only chance that planet ever has to establish an ETC. To understand why, just imagine the outcome if our present civilisation collapsed, leaving what would inevitably be a relatively small number of survivors existing at a subsistence level. Unless the environment had become irrevocably hostile to humanity, it is reasonable to suppose that some kind of recovery could be made, based on utilising organic resources such as wood to make carts, ploughs etc. The problem would arise with the switch to the mineral-based economy (metal processing and fuel) which, as far as we are aware, is needed to achieve an ETC – because the easily accessible mineral deposits have mostly been exhausted. Even if our unfortunate successors knew where the remaining oil or metal ore deposits could be found, they would be unable to reach them without the advanced technology we deploy. It would be a classic Catch-22; they couldn't develop a technological civilisation without advanced technology! Perhaps they would find a different, non-mineral, route to a more sophisticated level of civilisation, but it seems highly unlikely that this would result in the technology needed to communicate with ETCs, let alone travel to them.

SF is full of beautiful dreams about humanity spreading through the galaxy and meeting other technological civilisations (or nightmares if they turn out to be hostile). Sadly, these are looking increasingly like fantasy rather than SF. I hope this is wrong, and that SETI will discover proof of ETCs, but I'm more pessimistic than I used to be.

Friday 1 May 2009

Global Warming and SF – Part 2

A few weeks ago I summarised the current state of the developing understanding among climate scientists concerning the increasing rate of change in our climate. Even the 'most-likely' scenarios are now looking grim – the worst-case ones don't bear thinking about. So, what (if anything) can we do about it? What kind of measures might a realistic near-future SF story include?

There are basically four different approaches, most if not all of which may be needed in order to have a significant moderating effect on climate change. These are: to cut back CO2 production; to remove CO2 already in the atmosphere; to reduce insolation (heat received from the sun); and finally to adapt to the changes which are now inevitable, it being already too late to prevent some of the consequences of warming. I'll take each of these in turn.

Cut back CO2 production

This is the best known approach, or rather a whole cluster of different approaches under the same general heading. The techniques available range from the simple and obvious to the complex and difficult. The former are being applied already, to a greater or lesser extent in different places, but the latter will need strong political will on an international basis; i.e. they're not likely to happen until the consequences of climate change have become so obvious – and obviously bad – that not even short-termist politicians can ignore them.

Save energy - buildings: The relatively easy measures include changing building designs to minimise the need for heating in cold countries and for air-conditioning in hot ones. The former is well understood and already widely practiced; it requires good insulation standards, preferably including heat-recovery ventilation systems. The beauty of this is that most such measures can be retrofitted to most existing buildings, an important point given that complete replacement of our building stock will take a very long time. Measures to reduce air conditioning (likely to become increasingly important as the globe warms up) are less common and may be more difficult to apply to existing buildings. Some techniques are similar to the cold-climate ones – better insulation, smaller windows – but could also include installing an oversized 'floating' roof canopy, detached from the main structure, to provide shade without transmitting heat to the building. Some buildings are cleverly designed to have a ventilation system driven by natural convection, while 'green' roofs and walls – covered with plants – have been found to have a significant effect, not only in providing shade but in evaporative cooling. You do need a good water supply for these, though, which will be an increasing problem in many hot areas. Cooling systems using water circulating through underground pipes (a kind of reversal of the usual heat-pump heating system) may be more efficient than electrical air-conditioning.

Save energy – equipment and processes: Another well-known and much-practiced technique is the use of low-energy lights and appliances. Industrial processes are major users of power, an area which has probably received less attention so far than the domestic side.

Save energy – power generation: This is the major source of human-caused CO2 production, so non-polluting power generation has received a lot of attention in recent years, as demonstrated by the huge wind turbine farms sprouting up on land and in coastal areas. However, as is often pointed out, these aren't much good unless the wind blows. In fact, except for geothermal power, other sustainable power sources – hydro-electricity, tidal, wave and solar power – suffer from related problems in that the sources of power (even if reliable) are not constant, and may be a long way away from where they are needed. There is a potential solution to this, however; while AC current (in almost universal use) loses a lot of power when transmitted long distances, DC current does not. Until recently, converting DC to AC for domestic use was difficult, but solutions have been found. Some high voltage DC lines are already in use, and an international DC 'supergrid' has been proposed to link up Europe and North Africa. This will not only even out the supply from erratic sources such as wind power, but also provide access to solar power. Its proponents claim that a Europe-wide supergrid in conjunction with the full development of sources of sustainable power (mostly in the form of offshore wind farms) could reliably replace all of Western Europe's coal and gas power stations within thirty years.

Other alternatives being much discussed are the use of 'carbon capture' systems with fossil fuel power stations, by which the CO2 produced is trapped and pumped underground, and a revival in the use of nuclear power. The problems are that the carbon capture system is unproven (and some experts are dubious that it will work as advertised) and the supply of nuclear fuel is finite. Of course, if an economical source of fusion power could be developed that would solve most problems, but it's been 'coming soon' for about half a century and still seems a long way off, so it would be unwise to rely on that.

Interestingly, sustainable power is causing major divisions in the environmental lobby (a potentially fruitful source of SF plots). While all environmentalists are in favour of reducing CO2 production, some are also appalled by the alternatives, especially nuclear power, the visual blight of massive wind farms, and the potential effect on wildlife of huge engineering schemes such as the proposed tidal-power Severn Barrage in the UK. No doubt plans to cover vast areas of desert with solar collectors will result in similar protests.

These environmental protectionists argue that power generation systems do not need to be grand schemes. They believe that we should be thinking small-scale, with local generation of heat and power. Solar panels for water heating are commonplace now, and photo-voltaic solar cells are predicted to get a lot cheaper. These don't just work in hot and sunny climes; astonishingly, the world's major user of domestic PV cells is Germany, as a result of a scheme which provides significant financial rewards to people who sell their surplus power to the grid. However, while such schemes are well worthwhile and can reduce the demands on the power grid, the problem of the erratic supply of power from such sources can only be met by massive, interlinked, engineering projects.

Save energy – transport: This brings us onto another big polluter – transport. Much attention is being paid to road vehicles, with electric and hybrid (petrol/electric) vehicles in use and fuel cells being tested experimentally. Each of these systems, as presently conceived, has problems. Pure electric vehicles are limited to short-range use because of battery limitations. Furthermore, recharging batteries by plugging them into the grid isn't going to help much unless the electricity is generated from sustainable sources, so that would need to be in place to gain the full benefit from electric cars. Assuming that eventually happens, a battery swap system is proposed to allow drivers to change battery packs at service stations in the same way that they now fuel up, although there are indications that very fast-charging batteries may be on the way somewhat later.

Hydrogen cells, which develop electricity by combining hydrogen and oxygen in a kind of reverse electrolysis (the only by-product being water) are at a much earlier stage of development. Hydrogen has to be manufactured (not currently a very clean activity) and special transporting, storing and dispensing arrangements would need to be put in place. This seems unlikely to be adopted on a large scale without major government start-up funding, because manufacturers won't develop and make fuel-cell cars unless they are confident that people will buy them in large quantities, people won't buy fuel-cell cars unless there is a comprehensive network of hydrogen filling stations, and companies won't manufacture and distribute hydrogen, or equip the filling stations to dispense it, unless there is a proven demand (or someone else provides the start-up funding).

Taking all of this into account, the best approach for the near future is to have an electric car with plug-in recharging and an internal-combustion on-board generator to top up the batteries on a long run. This generator could be very small, as it would only need to supply cruising rather than full power. It could also run at a fixed speed, further improving efficiency. The next stage will probably be all-electric, using high-capacity fast-charging batteries, with fuel cells possibly coming along later.

Of course, mass transport tends to be the most efficient way of moving people, at least in areas of high population density. Tram and other light-rail systems are proliferating and will probably continue to do so. Unfortunately, there is a major problem with aviation. The growth in this is very bad news for the environment, not only because of the large quantities of CO2 and other pollutants produced, but also because they get ejected high in the atmosphere where they are far more damaging than at ground level. It is very difficult to see what can be done to ameliorate this, apart from taxing air travel so highly that it once again becomes the privilege of the rich few, but this would be politically virtually impossible. Hydrogen fuel would help, but planes designed to use this are so far off that they don't even seem to be being considered at the moment.

A different approach to reducing vehicle pollution is to make fewer journeys. Modern communications technology makes it feasible for increasing numbers of employees to spend at least part of their time working from home instead of commuting into cities. There is also growing criticism of our exploitation of cheap fuel in amassing "food miles" (the distance food travels before it reaches local shops), one example being fish originating in Scotland being sent to Poland for preparation and packaging before being sent back to the UK for sale. This has led to a growth in the UK in "farmers' markets", which are limited to selling local produce, bypassing the big commercial distribution networks. This is another aspect of the "think small, think local" movement already identified in the section on power generation. This issue, combined with a likely increase in international instability caused by climate change, may well see traditional food importing countries like the UK reverting to more domestic local production. Our gardens of the future may well consist of vegetable plots, as in the Second World War.

Making it happen – incentives: Clearly, the speed at which all of the above measures can be implemented (at least in free-market economies) depends on financial incentives, as demonstrated by the German PV cell experience. It has been suggested that the simplest and most fool-proof method of encouraging the most efficient and sustainable use of energy for all purposes would be to tax all fossil fuels at source, when they are removed from the ground. This would not only discourage the use of fossil fuels, it would make sustainable energy sources more competitive on price. The major problem is that this would require global agreement, and that is inconceivable in present circumstances (when countries can't even agree to tax all aviation fuel). Maybe much later, if the environment is sliding into chaos, by which time it would probably be far too late.

The population problem: As mentioned in Part 1, an underlying problem which is going to undermine all of the attempts to minimise CO2 production is the projected huge rise in the world's population, from about 6.4 billion now to around 9 billion by the middle of this century. Although population forecasting is notoriously unreliable, anything remotely like this will cause enormous problems even without climate change. Unless, of course, there were to be devastating famines, epidemics or wars, with death rates orders of magnitude greater than anything seen to date, which is hardly an attractive option. Add in the predicted effects of climate change in drying out continental interiors, and such appalling outcomes become more likely as starving, desperate populations try to move to more fertile lands. It is hard to see a way to avoid this without drastic limits on childbirth, which even a dictatorship like China has struggled to enforce.

A different style of living: Can anything be done about coping with the population increase? The major problem is of course producing enough food, but the extra living space required will also be an issue, particularly since conventional housing developments use up a lot of land which might otherwise be growing crops. This suggests that different forms of living may be developed, possibly in the form of arcologies; huge buildings in which city-sized populations can live, work and play while occupying only a small fraction of the ground area of a conventional city – and also using up only a small fraction of the energy per person. By a not-so-strange coincidence, the novel on which I am (very intermittently) working, set a century into the future, takes place in such an arcology.

This subject is taking more space to cover than I expected, so the other possible measures to tackle global warming will have to wait until Part 3…