Is the Temperature Rising? The Uncertain Science of Global Warming

  • S. George Philander
Princeton University Press: 1998. Pp258 $35£22.50

‘Global warming’ has become a household term; it needs no explanation when used in the news. ‘Is the temperature rising?’ is a question of utmost interest to anyone concerned about the global environment. Both phrases announce the subject of this book.

The volume is based on a course for undergraduate students given by the author at Princeton University, so it is also well suited to educated laypeople. It is written clearly and contains informative figures. The extensive appendices provide additional technical material, and an eight-page glossary is included.

The author explains complex scientific concepts in a precise language and with delightful illustrations. Of the waves on the ocean's surface, he writes: “A breeze that blows over the ocean, like a bow that strokes a violin string, readily excites music in the form of waves. The audible sound of a violin is soothing when the pressure from the bow is gentle and becomes strident when the pressure is great. The ocean's music changes similarly from ripples ⃛ to foaming, lashing waves as the gentle breeze grows stiff ⃛ and becomes a gale that whips the ocean into frenzy.” He describes the weather as the “music of our sphere” and explains the principle of chaos using a thought-experiment of a skier losing his or her wallet on a slope. The book is a pleasure to read.

But its title is deceptive. Most of the volume explains the workings of the climate machinery and its components such as radiation, clouds, weather and oceans. The question ‘Is the temperature rising?’ is dealt with only on two pages in the last chapter.

The answer is ‘yes’, which will be no surprise to anybody who knows the observational record compiled by the University of East Anglia in England. The more interesting question ‘Will the temperature continue to rise?’ is dealt with in even fewer lines: the author quotes “very probable” rates of increase of 0.5-2 °C until about 2050, from studies of climate models forced with continually increasing greenhouse gas concentrations.

The author reduces the uncertainty of climate science mostly to the fundamental problem of nonlinear dynamics and the related problem of determining accurate initial conditions. Other fundamental aspects are neglected, such as the climate system's phase space with infinitely many degrees of freedom, the openness of the system and the need to impose various semi-empirical parameters on climate models. As a result, the book comes across as over-optimistic about the task of analysing and modelling the climate system and its sensitivity.

As to the science of global warming, the author takes this to mean the purely physical sciences, exploring myriad processes that take place in the atmosphere, the oceans, the lithosphere and so on. Thus a planetary-scale view of global warming emerges, with relocated deserts, rising sea level, a defunct Gulf Stream and more El Niño events. What these changes mean for humankind is not specified. Instead, the author stays vague, mentioning the “considerable inconvenience over the next few decades for our particular species” and issuing general warnings about forthcoming unspecified “dangers”.

The science of global warming should, however, also deal with the specifics of these dangers: that is, it should look at the possibility of abating and adapting to them. And as ecosystems and people experience global warming mostly locally, this analysis must be done on the local scale.

The author mentions Thomas Malthus's prediction, 200 years ago, that England was heading towards “gigantic inevitable famine” because of the steady increase in population. Perhaps we should learn from Malthus's science that the fate of the environment and humankind is only partly determined by natural dynamics, such as population growth and the carbon cycle, and that social dynamics and technological innovations are important as well.

Every scenario of possible future climate change is based on scenarios about the anthropogenic output of greenhouse gases: that is, on the outcome of a highly complex social system. The challenge of climate science therefore is to integrate the social sciences — by coupling economics models, diagnosing the socio-scientific construction of the ‘climate problem’ or analysing the impact of climate policy on people's well-being. Unfortunately, the author has chosen not to take up this challenge; and where he refers to old misconceptions, such as the infamous “climate and civilisation” hypothesis of Huntington, he fails to put them in proper perspective.