• Email
  • Single Page
  • Print

A Great Jump to Disaster?

The idea that Earth is a living thing goes back at least as far as Plato, who according to Francis Bacon believed that the planet “was one entire, perfect, living creature.” But it was James Lovelock and his colleague Lynn Margulis who, in the early 1970s, developed a testable scientific hypothesis aimed at investigating Earth’s lifelike properties. Known as the Gaia hypothesis, it states that life on Earth works to keep conditions at the planet’s surface favorable to life itself. In 2006 this led to Lovelock joining the likes of Louis Agassiz and Charles Darwin in receiving geology’s most prestigious prize—the Geological Society’s Wollaston Medal. In presenting the award the society’s president acknowledged that the Gaia hypothesis had “opened up a whole new field of Earth Science study.”

flannery_1-111909.jpg
Chris Jordan
An albatross chick on Midway Atoll, raised on plastic that its parents mistook for food from the polluted Pacific Ocean, September 2009; photograph by Chris Jordan

The Gaia hypothesis has now evolved, according to Lovelock, into a full-fledged scientific theory (in science hypotheses are held to be untested ideas put forward to explain facts, while theories have been tested and are generally considered true). Part of the testing came in 2001 when scientists from four international climate research programs reasserted the hypothesis’s basic tenets: (1) Earth “behaves as a single, self-regulating system”; (2) “human activities are significantly influencing Earth’s environment”; (3) Earth’s system is complex and difficult to predict, and “surprises abound”; (4) the system is characterized by “critical thresholds and abrupt changes”; and (5) Earth’s system has “moved well outside the range of natural variability exhibited over the last half million years at least.” Yet despite such support, the transformation of the hypothesis to the status of a theory is still widely disputed.

The Gaia concept and climate change science are intimately connected, and Lovelock has spent most of his career trying to understand the consequences of increased greenhouse gas concentrations in the atmosphere. In his latest book, The Vanishing Face of Gaia: A Final Warning, he argues that Earth’s system of self-regulation is being overwhelmed by greenhouse gas pollution and that Earth will soon jump from its current cool, stable state into a dramatically hotter one. All climatologists acknowledge the existence of such climatic jumps—as occurred for example at the end of the last ice age. But chaos theory dictates that the scale and timing of such leaps are inherently unpredictable, which means that they cannot be incorporated into the computer models of Earth’s climate system that such scientists use to project future climate change. Yet this is precisely what Lovelock attempts to do—using his own computer modeling—in The Vanishing Face of Gaia. A new climatic jump, he concludes, will occur within the next few years or decades, and will involve an abrupt increase in average global surface temperature of 9 degrees Celsius—from 15 to 24 degrees Celsius (59 to 75 degrees Fahrenheit). Such a shift, he contends, will trigger the collapse of our global civilization and the near extinction of humanity.

In contrast, the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), which was released in 2007, predicts a likely rise of 2–3 degrees Celsius (4–6 degrees Fahrenheit) this century. Lovelock argues that the IPCC projections are incorrect because they do not include temperature jumps, yet as we’ve seen such jumps are widely held to be impossible to model. He also points out that data published subsequent to the IPCC’s research cut-off point of early 2005 show that their projections are too conservative. Support for this view has come from a climate science summit held in Copenhagen in March 2009 attended by 2,500 delegates, which concluded that “the worst-case IPCC scenario trajectories (or even worse) are being realised.”

So what makes Lovelock think he can predict the timing and scale of future climatic leaps? His findings are based on experiments conducted with a simple kind of computer model that is used by climate scientists to diagnose the accuracy of larger climate models. This revealed that signs of climatic instability are likely to appear as the concentration of CO2 reaches 400 parts per million (ppm). Then when CO2 reaches a concentration of 400–500 ppm, the computer model predicts a sudden rise in temperature of 9 degrees Celsius. But just before that major temperature jump a strange thing happens—the temperature dips for a few years. As Lovelock puts it, if his model

truly represents the Earth’s response to increasing carbon dioxide, it is scary because it implies that before the final jump to a desert world, the climate will briefly become cooler again. This warns that a cold summer, or even a series of them, is not proof that global heating has ended.

Another way of putting it is that normal climatic variation will precede Lovelock’s 9 degree jump in temperature. This is hardly useful as a predictive tool, and indeed Lovelock’s approach to the problem clearly will require further scientific corroboration before it is accepted.

But if we assume Lovelock is right, how close might we be to the temperature jump predicted in his model? Prior to the industrial revolution, the concentration of CO2 in the atmosphere was 280 ppm. Today it’s around 390 ppm. But the combined warming effect of all the greenhouse gases in the atmosphere, if expressed in terms of the warming potential of carbon dioxide, is around 430 parts per million. If Lovelock’s model is to be believed, the fatal jump could occur any day. Because such an imminent climate shift would have grave consequences, it would be rash to disregard his warning out of hand.

As we try to assess Lovelock’s highly individualistic work and decide whether his message is worth listening to, there is no better guide than John and Mary Gribbin’s James Lovelock: In Search of Gaia. Essentially a dual biography, it deftly recounts in alternating chapters the development of climate change theory and the life of Lovelock himself.

Born on July 26, 1919, into a working-class family, Lovelock believes that he was “a product…of the celebration of Armistice Night at the end of hostilities in World War 1.” A convert to the Quaker faith and until 1944 a conscientious objector, Lovelock graduated from Manchester University in 1941 and soon thereafter took up a position as a “glorified lab assistant” at the National Institute for Medical Research. There he seems to have been curious and skeptical about everything, and when medical staff explained to him that disinfectant sprays killed airborne bacteria because droplets bumped into them, he set about calculating the probability that a droplet of disinfectant would actually encounter an airborne bacterium.

The chances were so low, he discovered, that many bacteria would survive for at least a day after a room was sprayed, leading him to deduce that the sprays work because disinfectant evaporates from the droplets and, having evaporated into the atmosphere, it can kill bacteria. He tested this idea by using a nonevaporating disinfectant, which was ineffective, and an identical but evaporating one, which “killed bacteria like the clappers.” He was also the researcher who demonstrated that the common cold was transmitted via touch rather than through the air.

Lovelock’s exceptionally effective research method derives from a strong capacity for empathy. When working on a problem he quite literally tries to envisage himself in the role of the subject being considered: in the case just mentioned, a bacterium and a droplet in the vastness of the atmosphere; and presumably, when considering the responses of Gaia to CO2 pollution, Earth as a whole. Indeed he often describes Gaia as an elderly lady, and at ninety Lovelock is no youngster himself.

In 1946 Lovelock received a doctorate from the University of London for his studies in air hygiene. His work involved the invention of scientific instruments, the most influential of which allow for the detection of almost unimaginably small traces of pollutants. One such device, which remains in widespread use, is known as the electron capture detector. It operates like a conventional gas chromatograph—a machine in which samples of air are passed through a tube containing fine powder, which forces the various molecules in the samples to be absorbed at different points along the tube. But it also allows for the identification and counting of individual molecules of pollutants such as chlorofluorocarbons (CFCs—the chemicals responsible for the destruction of the ozone layer) in a sample of air.

Using the electron capture detector while on holiday on the west coast of Ireland in 1969, Lovelock discovered that the air contained 50 parts per trillion of a manufactured chemical known as CFC-11. This, he surmised, had blown in all the way from America, prompting him to wonder whether the entire atmosphere was already polluted with CFCs. To test this hypothesis, in 1971 he took his machine on a research vessel bound for the Antarctic. He discovered the pollutant everywhere, and within a few years the data he collected were being investigated by researchers interested in the destruction of the ozone layer. Strangely, Lovelock initially dismissed the idea that CFCs could be responsible for the ozone damage, and appeared as chief scientific witness during US Senate hearings for Du Pont, the main manufacturer of the offending chemicals. Because he presented an objective view of the science as it was known at the time, Lovelock claims that he could as well have appeared for the other side, if only they had asked him.

The concept of Gaia came to Lovelock suddenly “one afternoon in September 1965.” He was visiting the Jet Propulsion Laboratory in California when an astronomer brought him data demonstrating that the atmospheres of Mars and Venus were composed almost entirely of CO2. The high levels of oxygen in Earth’s atmosphere, resulting from the breakdown of CO2, stood in stark contrast. When he mentioned this to the astronomer Carl Sagan, Sagan told him of the “faint young sun paradox,” which states that while the sun was 25 percent cooler when Earth was young, our planet never froze over as it should have. It was then that “the image of the Earth as a living organism able to regulate its temperature and chemistry at a comfortable, steady state emerged in my mind,” Lovelock recalled.

The trail of scientific discoveries leading to this moment is long indeed; the Gribbins trace it back to the work of Robert Boyle, a founder of the Royal Society, who in the seventeenth century described the atmosphere as “exhalations of the terraqueous globe.” A century later Joseph Black demonstrated that the “exhalations” were a mixture of gases, and the first one he isolated was CO2, then known as “fixed air.” In the 1820s the French mathematician and physicist Jean-Baptiste Joseph Fourier began to ponder why Earth’s temperature was maintained at its current level. A keen student of how heat was transmitted, he tried to calculate how hot Earth should be, given its distance from the sun, and came up with a figure of -15 degrees Celsius (5 degrees Fahrenheit).

  • Email
  • Single Page
  • Print