"Flow" by Philip Ball

A study of the science of flow that offers many pleasures to the reader (but a clear statement of the book's aims is not one of them)

This is another of Philip Ball's quirky, scholarly, illuminating studies of the patterns of nature, the second in a trilogy. The others deal with shapes and branches; this one deals with flow of all kinds, from convection in the sun to avalanches in a pile of rice.

Ball has struck popular science gold with this trilogy, because he has a subject matter that is at the same time scientifically intriguing, visually engaging, and easy for the layperson to grasp. Fluid flow -- the paradigm of flow in this book -- is a typical case. Eddies and turbulence are interesting for scientists because they are horribly complicated. But because they are horribly complicated, the only hope of understanding many features of fluid flow is through a kind of simple qualitative modelling, the kind that is easy to explain to a popular audience. The Kelvin-Helmholtz instability, for example, is a mechanism by which flowing water forms wavy currents. It is a simple mechanism, communicable in a picture, and it creates delicate plumed patterns in water that make great images. And like most of the patterns in this book, it crosses mediums easily -- it is present in clouds as well as rivers.It turns out, as Ball reveals in the last chapter of the book, that real turbulence is not susceptible to any simple models like the Kelvin-Helmholtz model. But this is a rare exception. And even with turbulence Ball finds a pretty way of illustrating the science: he concludes as he began the book, with a work of art. This artistic theme -- the first chapter is about representations of fluid flow in Western and Eastern art, with a focus on Leonardo Da Vinci -- is typical of Ball's playfulness in this trilogy, his fondness for interesting diversions. These are indeed diverting, but they can also be disorientating. In the case of this volume, I finished the first chapter without having much idea of what the book would be about.

This book is certainly about something, though, even if it that something is hard to pin it down. It's about fluid motions, of course: aside from the conventional topics of water flow and convection, we have intruiguing chapters on the collective behavior of grains (in dunes, piles, and sheets) and on the movement of flocks of animals, crowds of people, and lines of traffic. But it's also about deeper themes, which Ball mentions now and then but explains systematically. It's about trying to describe and understand a wide class of phenomena through a single parameter -- whether it is Rayleigh's number for describing the tendency of fluids to give convection patterns, or Reynold's number for describing the eddy-forming habits of a liquid stream. In a vague way it is about self-organisation, the capacity of macroscopic entities to form complex patterns with no outside help except a steady influx of energy. And in a fleeting way it is also about self-organising criticality, the quality that some phenomena have of spontaneously entering highly unstable states -- a quality that the now-legendary sand-pile is supposed to have.

Readers who are not interested in these themes, perhaps because they would rather see them treated front-on rather than in the occasional sidenote, will still find plenty to enjoy in this book. The simplest pleasure it offers is to witness similar patterns in disparate phenomena: lane-forming on human footpaths and in the trails of army ants; convection not just in boiling water but inside the earth, in clouds, in cereal packets, and in the regularly-spaced circular craters that shape some landscapes in Norway and Alaska. Another of the book's pleasures is its narration of the process of science, the sequence of attacks by different scientists, using different methods, on the same problem. In Flow, Ball's account of successive attempts to explain sand dunes is typical of his blow-by-blow coverage of the process of discovery.

The breadth and detail of Ball's interests in this book means there are many other pleasures besides, from the historical (Faraday's prescient thoughts on convection in grains) to the domestic (an explanation of why shaking a cereal packet drives the chunky bits to the top). The downsides are that the scientific detail is sometimes heavy-going, and that the underlying themes of the book (aside from the general idea of fluid motion) are nebulous. On a more specific note, Ball's discussion of self-organising criticality did not ease much of my confusion about that topic. On the whole, however, Flow deserves its place in Ball's trilogy -- and that is high praise.

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Are all environmentalists hypocrites?

Maybe, but it's better to be hypocritically active than honestly inactive

Hypocrisy is a useful tool for environmentalists. Show the world that Shell is tearing up the sands of Alberta and the world shrugs. Show the world that Shell is tearing up the sands of Alberta, and at the same time advertising themselves as a green company, and the world pricks up its ears. Dishonest wrong-doing carries more weight than mere wrong-doing.

But hypocrisy is one of those tools that can easily turn on its users. Those who make moral claims are expected, on pain of hypocrisy, to back them up with unambiguous action -- environmentalists included.

This is fair enough, but sometimes it seems to go too far. Tell someone you've quit meat to reduce carbon emissions, and friends and foes alike will wonder aloud why you are still driving a car, buying imported fruit, etc. etc. Spend a year living cashfree and a mob of commenters will call you a hypocrite for submitting a blog post by broadband. It seems that people who try to do good, and succeed imperfectly, are more guilty than people who don't try at all. Is this fair?

The hypocrisy of some actions is indisputable, and indisputably a vice. Shell's hypocrisy is worse than mere wrong-doing because it is a lie designed to downplay the extent of their wrong-doing. Is it just as bad to be a selective environmentalist, one who picks and chooses their good works depending on what is convenient for them (assuming that leaving a Western-sized carbon footprint is a wrong-doing)?

There has been a lot of scholarly ink spilt on the nature of lying and on whether or not wrong-doers forfeit their right to complain about the actions of others. Which is to say that it would be easy to get one's knickers in a philosophical twist on the topic of hypocrisy.

But the following points seem to me salient, obvious, and within the grasp of people (like me) who want to think about this issue but do not want to think too hard.

Firstly, it is not a good thing for an individual to be deluded about the extent of the harm he inflicts on the world, for the simple reason that such an individual is less likely to reduce the harm they inflict.

Secondly, in at least some cases it is wrong for an individual to deceive others about the extent of his wrongdoing. If I put it about among Ethiopians that I was down to 1.2 tonnes of CO2 a year when in fact I was not, then I would be a lot like Shell when they put it about among Britons that they are a clean company when in fact they are pumping Alberta's dirt into the atmosphere.

Thirdly, a person who takes some action to reduce their carbon footprint, but not all possible action, does not automatically deceive himself or anyone else. It might be perfectly clear in his mind that his actions are of real but limited use, and he may never lead anyone to believe otherwise.

Fourthly, it is better to take some good action on climate change, and be a bit deluded or dishonest about the value of those actions, than to take no action at all now or in the future. A population of frank and knowing individuals is not much use if none of them reduce emissions.

Fifthly, and finally, the fear of being called a hypocrite should not stop people from making incremental changes to their lives in the interests of the environment (or in the interests of any other worthwhile cause). The fear of being a selective environmentalist should not turn people into timid environmentalists. The alternative is damaging, absurd, and selfish.

It would be damaging because most environmentally-friendly action by individuals will be step-by-step action. Wipe out incremental action and you wipe out most action.

It would be absurd because the charge of hypocrisy assumes that the accused party has some wrong-doing to hide: I would be a lier, but not a hypocrite, if I said I would do five handstands but only did three. So if the fear of being hypocritical has any bite, it should urge us to take more action, not less.

And it would be selfish, because -- if Lord Stern and the IPCC are even half-way right -- the social inconvenience of being called a hypocrite is minute compared to the harm that will be avoided if individuals take real action on climate change. Hypocrisy on climate change is a bad thing, from Shell or anyone else. But inaction is much worse.

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"Science and Islam" by Ehsan Masood

An accessible and enlightening survey of Islamic science during the so-called Dark Ages and beyond

"Animals engage in a struggle for existence [and] for resources, to avoid being eaten and to breed...Environmental factors influence organisms to develop new characteristics to ensure survival, thus transforming into new species. Animals that survive to breed can pass on their successful characteristics to [their] offspring."

Is this Richard Dawkins writing in the 21st Century? Or Lamarck in the 19th? Or some godless renegade in 17th Century Europe? Not even close. The author is al-Jahiz, a science writer from 9th Century Baghdad. The surprising thing is not that an Islamic author could write such a thing so early, but that we are surprised to learn that he could -- that's what Ehsan Masood would say, at any rate. And readers of Science and Islam will probably agree with him by end of this lively and user-friendly book on Islamic science during the so-called Dark Ages and beyond.

Part 1 of the book mixes a potted history of Islam with descriptions of the patrons, institutions and practitioners of science in each major regime from 700AD to 1300AD. The story is long but compactly told. In the space of four chapters and seven centuries, Islamic science flowers in Damascus, Baghdad, and Egypt before being cut down by the Mongols and Tartars. Along the way Masood sketches some of the many colourful figures of the time, like the bird-man ibn-Firnas and the scientific advisor who is unable to build a damn on the Nile and feigns madness to avoid the wrath of his caliph.

Part 2 hones in on the science of this "staggering renaissance." Masood covers medicine, astronomy, mathematics, chemistry, and engineering, in that order, with a post-script on evolution, optics, and Islamic universities. When describing the heroes of Islamic science and their remarkable work, Masood keeps one eye on their Greek heritage and another on their European successors. Comparisons are odious, but illuminating: Islamic scientists are all the more impressive when we learn that they questioned Galen on medicine, challenged Ptolemy on cosmology, and made direct contributions to the work of Copernicus, Kepler, Fermat, Newton, and the engineers of the industrial revolution.

Part 3 looks at Islamic science in the 19th and early 20th century, and draws some lessons for the future. This is not just an epilogue. It asks what the scientific revolutionaries of the 17th Century thought about Islamic science, whether the Ottomans were wise to borrow from Western science in the 19th Century, and whether imperialist science was a good thing for India. These are all delicate questions with ambiguous answers, and Masood gives a balanced survey. To end, he picks up a thread that runs right through the book, the violence of pro-science Islamic rulers. "If science is to return to the nations of Islam," Masood concludes, "it must do so without interfering with people's freedom to believe."

This conclusion is wrong if taken too literally. Surely a belief in evolution (for example) will interfere with a person's freedom to believe that the earth was created 6000 years ago -- and rightly so. Still, Masood does well to remind us that dictatorial rule does not help the cause of science, even if the dictator is pro-science. This book also reminds us of another easy-to-forget truth: for most of its history, Islamic science flourished alongside the teachings of Muhammad, not in spite of them -- and sometimes, as for medicine, it flourished because of those teachings.

Science and Islam has some gaps. Sometimes Masood left me hanging after skipping past what seemed to be key achievements in Islamic science. One is the passage quoted at the top of this review, which summarises not just evolution but also a mechanism for evolution that resembles evolution by inherited characteristics; another is the controlled clinical trial conducted by the medic al-Razi to test the theory of bloodletting. Clinical trials and evolution are such monuments of modern science that I expected Masood to say more about their role in Islamic science. Also, Islamic science from 1300 to 1800 gets little attention -- which is fine for such a small book, but Masood does not explain the omission.

Topics that require equations or diagrams are not well-covered. When it comes to Islamic optics Masood gives 4 pages to theories of sight -- which are easy to describe qualitatively -- and only 2 paragraphs to refraction, reflection, and other theories of how light travels. The chapter on number gives a good survey of Islamic mathematicians but is light on algebra, perhaps their most important contribution in this field. A diagram or two in the chapter on astronomy may have clarified concepts such as the "Tusi couple", a mathematical tool for simplifying Ptolemy's model of the heavens. However, in place of technical detail the book has up-to-date scholarship, an asset for understanding the Islamic influence on Copernicus, the water clocks of al-Jazari, and numerous other topics.

Science and Islam faces the dual challenge of covering a technical subject (science) and a neglected period of history (the East during the Dark Ages). The book is aimed at a general audience, the majority of which will be unfamiliar with one or both of these topics. Masood answers both challenges well. His smooth prose and bite-sized format are easy on the novice palate (there is a new sub-chapter every 2 pages or so). All but the most learned readers will come away with their image of both science and Islam refreshed.

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"The Origins of Meaning" by James H. Hurford

A detailed and scholarly, but accessible, survey of the evolution of linguistic meaning

This is unmistakably an academic book, more useful to the layperson as a reference than a bedtime read. But it is saved from 2 stars by the down-to-earth style of the author, which means that non-scientists can come to grips with its fascinating subject matter without too much effort.The grand-sounding title shows just how ambitious is the task that Hurford sets himself in this volume. His aim is nothing less than to show how the "semantic" and "pragmatic" sides of human language -- roughly, concepts and conversations -- grew out of the non-linguistic abilities of our distant ancestors. But anyone who expects a blow-by-blow narrative of how this happened, with the dates of each key development, will be disappointed. Instead Hurford describes the cognitive and behavioral abilities of non-humans that stand out as precursors to language, and then describes the evolutionary mechanisms that could have transformed these primitive capacities into the rich array of concepts and conversational skills that humans have today. The result is more flow-chart than timeline, a schematic account of how psychology, biology, and ecology combined to give modern-day linguistic meaning.

Hurford, Professor of General Linguistics at the University of Edinburgh, cuts no corners in surveying the theory and evidence that decades of scientific research have brought to bear on his topic. This makes the writing dense at times, as Hurford runs through studies, counter-studies, and rival interpretations of data. But it also makes the book an excellent starting point for anyone interested in exploring the topic further. Also, Hurford's comprehensiveness means he covers not just the evolution of language but also some large areas of general interest, like animal cognition and the evolution of cooperation.

The book is driven by academic rather than popular aims, but Hurford's prose makes it much more accessible than it could have been. The book covers an impressive range of specialty fields, from philosophy of mind to kin selection theory, so Hurford can't afford to lapse into the jargon of any one of these specialities. And he does a good job of keeping all readers in the loop, spelling out the meanings of technical terms and describing in plain language how each chapter fits into the bigger picture.

While readable, the book will be dry to anyone used to popular science writing. But the reward for the patient reader is a steady flow of probing questions, clever experiments, and curious findings. In what way is language a cooperative exercise? If language evolved by sexual selection, why are human males and females equally competent at language? What happens in a monkey's mind when it responds to an alarm call from a fellow monkey by running away? Is this behavior hard-wired, or does the momkey form a concept of "predator" in its mind and respond to that concept? What came first: pure speech acts that expressed sentences like "hello" or "I'm here", or descriptive statements like "That plant is poisonous"? Scattered among the answers to these and many other questions are quirky phenomena such as mice who dream, humans who understand lip-pointing but not finger-pointing, and pigeons who can distinguish between works from the Picasso and Monet schools of painting.

The argument running through the book is that non-human animals have more mental capacities than previously thought, and hence that the gap between the language abilities of humans and non-humans is smaller than previously thought. For a lay reader this is probably the most engaging and surprising aspect of the book: from the multiple alarm calls of the ververt monkey to the idea of "opposite" possessed by great apes, animal concepts and conversations are richer than we usually give them credit for. Of course sometimes the limits of non-humans is also clear -- for example, even a basic communication device such as pointing to refer to an object is very rare among our closest relatives in the wild.

This book is gristly and unsweetened, not recommended as light reading. But digested slowly, over many sittings, it is a feast of insights into the nature of language, animal cognition, the social role of communication, and the evolution of all three.

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"Machine Intelligence" by Ashwin Srinivasan

An enjoyable collection of writings by a pioneer of AI and IVF

This is an eclectic collection of writings by and about Donald Michie, the Scottish-born scientist whose career spanned over half a century and covered many topics, most notably computer science and reproductive biology. Michie died in a car accident in 2007, aged 84, and "Machine Intelligence" is a tribute to his life and work compiled by the eminent computer scientist Ashwin Srinivasan.

The book varies widely in style and subject matter, but it is interesting and readable throughout. It comes in three parts, "Machine Intelligence," "Biology," and "Science and Society." Each section is divided into chapters containing 3-5 pieces, with helpful introductions to the chapters by Srinivasan. The writing is aimed at the non-specialist reader, and specialists may be disappointed by the absence of any of Michie's many ground-breaking scientific papers. The upside is that experts and novices alike are treated to insider accounts of Michie's code-breaking at Bletchley Park during WWII, reflections by Michie on how scientists work and the role of government in science, and thoughtful discussions of big topics in AI -- such as the Turing test and the role of subconscious or "inarticulate" thought in cognition. Especially worthwhile are Michie's thoughts on the difference between brute-force solutions to computing problems and truly intelligent solutions.

Michie was much more than a scientist, and some of the most witty and enjoyable writing in the book sees Michie as science administrator, social commentator, and popular science writer. Some of my favourites are his cutting comments on the Lighthill Report (the government report in the early 1970s that almost killed Britain's nascent AI industry), his article about the reading habits of scientists (they do surprisingly little), and his account of a bizarre trek from London to Moscow that Michie undertook at the height of the Cold War.

"Machine Intelligence" is not a detailed or systematic treatment of Michie's ideas -- it's a series of snapshots rather than a portrait. Articles on the same theme (like the difference between clever and intelligent computers) are sometimes scattered through the book rather than grouped together. And there are too many typographical errors. But "Machine Intelligence" succeeds as a readable tribute to a remarkable man, giving many glimpses of Michie's insight, humour, and wide-ranging enthusiasm for science.

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Three Degrees: Botswana dunes, Indian monsoon...

More consequences of global warming, according to peer-reviewed science cited in Mark Lynas' book. (But why?)

Botswana sand dunes. Large parts of the Kalahari desert are covered in a layer of brush and scrub, and can be farmed. At least two studies, the latest in 2005, have suggested that by the time the globe hits 3 degrees the Kalahari hills will have "remobilized": a combination of high winds, high temperatures and low rainfall will strip them of their fertile cover, making then unsuitable for crops and animals.

Thomas, D., et al, 2005: 'Remobilization of the southern African desert dune systems by twenty-first century global warming,' Nature, 435, 1218-1221

Pliocene warming. 3m years ago the Arctic and Antarctic seas were clear of summer ice, shrubs grew in the Transantarctic mountains, 500km from the south pole, and were around 25m higher than today. Scientists think CO2 is mainly responsible for the temperature rise. The overall temperature at this time was around 3 degrees higher than today. CO2 concentrations were about the same as they are today. Thousands of years passed before this temperature and concentrations warmed the poles, but the similarity to today's figures is alarming.

Francis, J., and Hill, R., 1996: 'Fossil plants from the Pliocene Sirius Group, Transantarctic Mountains; evidence for climate from growth rings and fossil leaves,' PALAIOS, 11, 4, 389-396

Haywood, A., and Williams, M., 2005: 'The climate of the future: clues from three million years ago,' Geology Today, 21, 4, 138-143

Haywood, A., and Valdes, P., 2004: 'Modelling Pliocene warmth: contribution of atmosphere, oceans, and cryosphere,' Earth and Planetary Science Letters, 218, 363-77

Forest fires in Australia. The CSIRO Atmospheric Research has predicted that 35 degrees days in Queensland could occur 2 to 7 times more often than they do today. Higher winds, and up to 25% less rainfall, would also add to the fire risk in the state. This would lead to more events like the 2003 conflagaration outside Canberra, which killed 4 people, destroyed 500 buildings, and in ten minutes released more energy than the Hiroshima atomic bomb.

Hennesseym K., et al., 2004: 'Climate Change in New South Wales: Part 2 -- Projected changes in climate extremes,' CSIRO, November 2004, 7pp

Fromm, M., et al., 2006: 'Violent pyro-convective storm devastates Australia's capital and pollutes the stratosphere,' Geophysical Research Letters, 33, L05815

The Arctic again. A 2000 study predicted that around 80% of Arctic sea ice would disappear once the mercury hit 3 degrees. A more recent study (in 2007) concluded that Arctic melting was running 30 years ahead of its forecast rate.

Johannessen, O., et al., 2004: 'Arctic climate change: observed and modelled temperature and sea ice variability,' Tellus, 26A, 328-41

Stroeve, J., et al, 2007: 'Arctic sea ice decline: Faster than forecast,' Geophysical Research Letters, 34, L09501

Central America. Drought is forecast for Central America, with the Hadley Centre predicting a rainfall decline of 1-2mm per day in this region. This would leave the area vulnerable to calamities like the drought in 2001, which led to food shortages among around 1.5 million people. Severe warming could lead to droughts on the scale of those that laid waste to the illustrious Mayan civilisation in the early Medieval period.

Johns, T., et al., 2003: 'Anthropogenic climate change for 1860-21-- simulated with the HadCM3 model under updated emission scenarios,' Climate Dynamics, 20, 583-612'

Indian Monsoon. The monsoon over the subcontinent is expected to become heavier but less regular, leading to more extreme flooding in India and Bangladesh and a greater likelihood of dry periods in the region. Given the vast populations in the area, and their reliance on agriculture, "The reliability of the Monsoon is...a matter of life and death for millions of people" (Lynas' words).

May, W., 2004: 'Simulation of the variability and extremes of aily rainfall during the Indian summer monsoon for present and future times in a global time-slice experiment,' Climate Dynamics, 22, 183-204

Ueda, H., et al., 2006: 'Impact of anthropogenic forcing on the Asian summer monsoon as simulated by 8 GCMs,' Geophysical Research Letters, 33, L06703

Dairaky, K., and Emori, S., 2006: 'Dynamic and thermodynamic influences on intensified daily rainfall during the Asian summer monsoon under doubled atmospheric CO2 conditions,' Geophysical Research Letters, 33, L01704

Drying of the Indus river. The Indus river runs from the Karakoram range that straddles Pakistan and south-west China. Karakoram is the largest glaciated area outside the poles. According to a 2005 WWF study, all of the major ice-capped areas in the Karakoram and Himalayan region are melting at an accelerated rate. A study commissioned by DFID concluded that after a period of high flows due to meltwater, the Indus will contain 20 to 40 percent less water by 2080. With few other sources of water available to it, either inside or outside the coutry, Pakistan could plunge into a food and water crisis.

WWF Nepal Program, 2005: An Overview of Glaciers, Glacial Retreat, and Subsequent Impacts in Nepal, India, and China, WWF, March 2005, 70pp

Rees, G., and Collins, D., 2004: An Assessment of the Potential Impacts of Deglaciation on the Water Resources of the Himalaya, DFID KAR Project No. R7980, 54pp and Annexes

New York floods. The New York metropolitan area has 20 million people, 2,400km of coastline, and a network of rail, tunnel and airport facilities whose entrances lie 3m or less above sea level. In a 3 degree world the sea level is expected to rise between 25cm and 1m, so that today's one-in-100-year flood could be a one-in-4-year event by 2080. Floods in 1992 and 1999 crippled the NYC transport system and left areas of Lower Manhatten under 1m of water.

Gornitz, V., et al., 2002: 'Impacts of sea level rise in the New York City metropolitan area,' Global and Planetary Change, 32, 61-88

North Sea storms. A 2001 study based on Hadley Centre models mirrors the predictions for New York weather: "In the southern North Sea," one of the authors wrote, "by the 2080s, a typical return period for what is now a 150-year event will be seven or eight years." The 1953 flood that caused 300 deaths in the UK and 1,800 in the Netherlands, and has been called UK's worst-ever natural disaster, was described at the time as a one-in-150-year event.

Lowe, J., et al., 2001: 'Changes in occurrence of storm surges around the United Kingdom under a future climate scenario using a dynamic storm surge model driven by the Hadley Centre models,' Climate Dynamics, 18, 179-188

The "sixth mass extinction of life." "Living dead" is the name ecologists give to populations whose numbers are so low they are doomed to extinction. A paper published in Nature in 2004 concluded that between a half and a third of species alive today will join the "living dead" by 2050 if the planet warms by over 2 degrees by that date.

Thomas, C., et al, 2004: 'Extinction risk from climate change,' Nature, 427, 145-148

Deserts in the Amazon. A 2000 paper from the UK's Hadley Centre (a world leader in climate modeling) predicted that a 3 degree temperature rise would commit the globe to another 1.5 degree increase by 2100 -- even if human carbon emissions stabilised once we hit 3 degrees. According to the Centre's models, 3 degrees of warming would "put the carbon cycle into reverse," as Lynas puts it: trees and plants would stop absorbing CO2 and start releasing it as they withered and died. The Amazon, 7 million km2 of lush vegetation, would be particularly vulnerable to this feedback effect: the Hadley models predict that by 2100 rainfall will drop to almost zero in some areas of the jungle, with temperatures soaring to 38 degrees on average.

[It must be said -- and Lynas says it -- that there is no consensus on the question of whether Amazon rainfall will drop low enough to trigger the feedback effect. A 2007 survey concluded that nearly half of the studies on the topic predicted an increase of rainfall for the Amazon. I include this topic because Amazon collapse is often cited as a key tipping point, and because if it did happen the consequences would be enormous.]

Cox, P., et al, 2000: 'Acceleration of global warming due to carbon cycle feedbacks in a coupled climate model,' Nature, 40, 184-7

Li, W., et al, 2007: 'Future precipitation changes and their implications for tropical peatlands,' Geophysical Research Letters, 34, L01403

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Two Degrees: China, South America, Europe...

More grim predictions from climate scientists, courtesy of Mark Lynas and his book

Droughts in Northern China. In a 1999 study, Chinese scientists showed that around 129 000 years ago, Northern China dried out and suffered continental-scale dust storms. China warmed by about 2 degrees during this period (the Eemian period) and the cold dry winter winds in the North responded much more quickly than the warm wet summer winds, causing massive dehydration. Lynas speculates that recent droughts in Northern China have the same root cause.

Chen, F. et al, 2003: "Stable East Asian monsoon climate during the Last Interglacial (Eemian) indicate by paleosol S1 in the Western part of the Chinese Loess plateau," Global and Planetary Change, 36, 171-9

Ocean acidification. Carbon dioxide dissolves in water to give carbonic acid. When there is enough CO2 in the atmosphere to raise temperatures by 2 degrees, there will also be enough to make large areas of the Southern Oceans and part of the Pacific effectively toxic to organisms with calcium carbonate shells. Affected organisms will include some varieties of plankton, the most important food source for ocean-dwellers. (Lynas likens this to spraying weedkiller over most of the world's land vegetation.)

Orr, J., et al, 2005: 'Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms,' Nature, 437, 681-6

The Royal Society, 2005: Ocean acidification due to increasing atmospheric carbon dioxide, Policy Document 12/05

Gazeau, F., et al, 2007: 'Impact of elevated CO2 on shellfish calcification,' Geophysical Research Letters, 34, L07603

Withering vegetation in Europe. The European heat-wave of 2003 caused -- among many other things -- a 30% drop in plant growth across Europe. Dying plants released an amount of carbon equivalent to one twelfth the annual carbon emissions from fossil fuels. Averaged across Europe, temperatures in Summer 2003 were 2.3 degrees above the norm.

Ciais, Ph., et al, 2005: 'Europe-wide reduction in primary productivity caused by the heat and drought of 2003,' Nature, 437, 529-33

Greenland melt. 115 000 years ago, melting ice meant that the sea level was 5-6 metres higher than today, yet average global temperatures were only 1-2 degrees warmer than today. Debate continues about how fast such melting can occur. But a 2007 study shows that sea levels are rising at 3.3mm a year, 50% faster than the 2007 IPCC report assumed.

Rohling, et. al., 2002: 'African monsoon variability during the previous interglacial maximum,' Earth and Planetary Science Letters, 202, 61-75

Tarasov, L., and Richard Peltier, W., 2003: 'Greenland glacial history, borehole constraints, and Eemian extent,' Journal of Geophysical Research, 108, B3, 2143

Rahmstorf, S., et al, 2007: 'Recent climate observations compared to projections,' Science, 316, 709

Drying India. A modelling study has concluded that a 2 degree increase in temperatures over India would decrease the agricultural yeild by 8%.

Kavi Kumar, K., and Parikh, J., 2001: 'Indian agriculture and climate sensitivity,' Global Environmental Change, 11, 147-54

South American water loss. In dry seasons the Rio Santa in Peru draws almost all of its flow from glacial melt. The melt from the glaciers is expected to drop by 40-60% by 2050. The Rio Santa powers hydroelectric turbines that are responsible for large-scale irrigation, 5% of Peru's electricity, and the drinking water for over a million people in the cities of Chimbote and Trujillo. (The 8 million people in Lima are also drawing for water on glaciers that are expected to dwindle in a 2-degree world, but no scientific studies have been conducted on Lima's glaciers.)

Kaser, G., et al, 2003: 'The impact of glaciers on the runoff and the reconstruction of mass balance history from hydrological data in the tropical Cordillera Blanca, Peru,' Journal of Hydrology, 282, 1, 130-44

Chevallier, P., et al., 2004: 'Climate change impact on the water resources from the mountains in Peru,' paper presented to the OECD Global Forum on Sustainable Development: Development and Climate Change, Paris, 11-12 November 2004

Juen, I., Kaser, G., and Georges, C., 2006: 'Modelling observed and future runoff from a glacierized tropical catchment (Cordillera Blanca, Peru),' Global and Planetary Change, 59, 1-4 37-48

California melting. California relies for its water on rivers stemming from the Sierra Nevada, Cascades and Rocky Mountains. During winter, more of this water is stored in "snowpack" in these mountains than in man-made reservoirs. A 2004 study predicted that this snowpack will decline by between a third and three-quarters in a 2 degree world. One study (Ruby Leung et al.) concludes: "Current demands on water resources in many parts of the West[ern US] will not be met under plausible future climate conditions, much less the demands of a larger population and larger economy."

Hayhoe, K., et al, 2004: 'Emissions pathways, climate change, and impacts on California,' Proceedings of the National Academy of Sciences, 101, 34, 12422-7

Ruby Leung, L., et al., 2004: 'Mid-century ensemble regional climate change scenarios for the western US,' Climatic Change, 68, 153-68

Crop failures. Crop failures are expected to be widespread in a hotter world, though failures in the tropics will be partially offset by successes at higher latitudes. In Mali, losses of maize crops are expected to leave up to three quarters of the population at risk of hunger, up from a third today. In Botswana, up to a third of the maize and sorghum crop could be wiped out due to a declining rainfall. A 2003 study predicts that North Sea cod population will disappear with around two degrees of warming.

Butt, T., et al., 2005: 'The economic and food security implications of climate change in Mali,' Climatic Change, 68, 355-78

Chipanshi, A., et al., 2003: 'Vulnerability assessment of the maize and sorghum crops to climate change in Botswana,' Climatic Change, 61, 339-60

Clark, R., et al, 2003: 'North Sea cod and climate change -- modelling the effects of temperature on population dynamics,' Global Change Biology, 9, 1669-80

Large-scale extinction. A study published in Nature in 2004 argued that over a third of all species on earth would be 'committed to extinction' if temperatures reach 2 degress in 2050. The lead author said in a Univeristy of Leeds press release that 'Well over a million species could be threatened with extinction as a result of climate change.' The study was based on models of expected movements of ecological niches due to changing climate.

Thomas, C., et al., 2004: 'Extinction risk from climate change,' Nature, 427, 145-8

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