The world's problem

Al Gore
AN INCONVENIENT TRUTH
The planetary emergency of global warming and what we can do about it
336pp. Bloomsbury. Paperback, £14.99.
978 0 7475 8906 8
US: Emmaus, PA: Rodale Books. $21.95.
978 1 5948 6567 1

Thomas E. Lovejoy and Lee Hannah, editors
CLIMATE CHANGE AND BIODIVERSITY
440pp. Yale University Press. £22.50 (US $35).
978 0 300 11980 0

Nicholas Stern
THE ECONOMICS OF CLIMATE CHANGE
The Stern Review
656pp. Cambridge University Press. Paperback, £29.99 (US $50).
978 0 521 70080 1

George Monbiot
HEAT
How to stop the planet burning
304pp. Penguin. Paperback, £17.99.
978 0 713 99923 3
US: Cambridge, MA: Southend Press. $16.50.
978 0 89608 779 8

Travis Bradford
SOLAR REVOLUTION
The economic transformation of the global energy industry
248pp. MIT Press. £16.95 (US $24.95).
978 0 262 026204 8
 
Alfred W. Crosby
CHILDREN OF THE SUN
A history of humanity’s unappeaseable appetite for energy
206pp. New York, NY: W. W. Norton. £14.99.
978 0 393 05935 9

Daniel C. Esty and Andrew S. Winston
GREEN TO GOLD
224pp. Yale University Press. £14.50 (US $25).
978 0 300 11997 8

The climate on our planet, over its billions of years of existence, has varied greatly – from times of the “snowball Earth”, to those when tropical animals roamed the poles. Even over the hundred thousand years or so of Homo sapiens’s tenancy, ice ages have come and gone. But the most recent 8,000 years, since the beginnings of agriculture and the first cities, have been unusually steady. Over this time, ice-core records show clearly that levels of carbon dioxide in the atmosphere have been around 280 parts per million (ppm), give or take 10 ppm. CO2 is, of course, the principal “greenhouse gas” in the atmosphere, and the density of this “blanket” plays a crucial, if complex, role in determining Earth’s climate. Some have indeed argued that the beginnings of agriculture, and the subsequent development of civilizations, is not a coincidence, but a consequence of this unusual steadiness.

Things began to change with the advent of the Industrial Revolution, first slowly and then accelerating during the twentieth century. CO2 levels reached 330 ppm by the mid-1970s, 360 ppm by the 1990s, 380 ppm today. This change of magnitude by 20 ppm over only a decade has not been seen since the most recent ice age ended, ushering in the Holocene epoch, around 10,000 years ago. If current trends continue, by about the year 2050, atmospheric CO2 levels will have reached more than 500 ppm, roughly double pre-industrial levels. There are long time lags involved here, which are hard to appreciate against the daily or annual rhythms we are accustomed to. Once in the atmosphere, the characteristic “residence” time of a CO2 molecule is a century. And the time taken for the oceans’ expansion to come to equilibrium with a given level of greenhouse warming is several centuries; it takes a very long time for water-expanding heat to reach abyssal depths. It is worth noting that the last time our planet settled to greenhouse gas levels as high as 500 ppm was some 20–40 million years ago, when sea levels were around 300 ft higher than today. The Dutch Nobel Prizewinner Paul Crutzen has suggested that we recognize our entry into a new geological epoch, the Anthropocene, which began around 1780, with James Watt’s development of the steam engine, when industrialization began to change the geochemical history of our planet.

In its recently published Fourth Report, 2007, the Intergovernmental Panel on Climate Change (IPCC), which brings together the world’s top climate scientists from 169 countries, estimates that global warming will be in the range of 2.4 to 6.4°C by 2100. This assumes that we will manage to stabilize greenhouse gas concentrations at around 450–550 ppm by that date (which could be optimistic); things get much worse at higher concentrations. This would be the warmest period on Earth for at least 100,000 years. Many people find it hard to grasp the significance of such a seemingly small change, given that temperatures can differ from one day to the next by 10°C. But there is a huge difference between daily fluctuations, and global averages sustained year on year. The difference in average global temperature between today and the coldest point of the last ice age is only around 5°C.

As explained by Al Gore, George Monbiot and many others, the impacts of a rise of around 2–3°C in global average temperatures are many and serious. Gore’s illustrations of retreating glaciers, drying lakes, melting ice sheets, spreading deserts and the disappearing snows of Kilimanjaro have a cumulative effect. One could disparage both the book and the film of An Inconvenient Truth as glossed-up PowerPoint presentations, but the entire planet would be better off if Gore had come across like this in 2000 to help the United States to get the President the majority voted for. Most of these impacts fall disproportionately on the inhabitants, human and non-human, of developing countries. Sea-level rise derives both from warmer water expanding and from ice melting at the poles. This will threaten not only low-lying islands and countries (such as Bangladesh), but also – at the higher levels of estimated temperature increase – major cities such as London, Shanghai, New York and Tokyo. There will also be significant changes in the availability of fresh water in a world where human numbers already press hard on available supplies. Some countries will be winners here, though now prone to floods.

More generally, we will see increasing incidence of “extreme events” – droughts, floods, hurricanes, heatwaves – the serious consequences of which are rising to levels that invite comparison with “weapons of mass destruction”. In particular, recent studies, made before Hurricane Katrina, suggest that increasing ocean-surface temperature (the primary source of a hurricane’s energy) will have little effect on the frequency of hurricanes, but strong effects on their severity; the damage inflicted by Katrina in 2005 has been estimated as equivalent to 1.7 per cent of US GDP that year. Based on simple projections of trends, estimates of the increasing annual costs of damage from such extreme weather amount to 0.5–1 per cent of global GDP by 2050, and will keep rising as the world continues to warm.

The timescales and magnitudes of other important and non-linear processes associated with climate change are less certain (non-linear means, roughly, that doubling the cause does not simply mean double the effect; huge and often irreversible “tipping points” can occur). For example, as the polar ice caps melt, the surface reflectivity is altered – dazzling white ice or snow giving way to dark oceans – causing more warming and faster melting; the timescale for the ice caps to disappear entirely is unclear, but such collapse would eventually threaten land that today is home to one in every twenty people. Similarly, as northern permafrost thaws, large amounts of methane gas are released, further increasing global warming (methane is a more efficient greenhouse gas than carbon dioxide). Nearer home for the British, increased precipitation in the North Atlantic region and increased freshwater run-off will reduce the salinity of surface water. Water will therefore be less dense and will not sink so readily. Such changes in marine salt balance have, in the past, modified the fluid dynamical processes that ultimately drive the Gulf Stream, turning it off on decadal time-scales. Although current thinking sees this as unlikely within the next century or so, it is worth reflecting that the Gulf Stream effectively transports “free” heat towards the British Isles amounting to roughly 30,000 times the total power-generation capacity of the UK.

Moving beyond ourselves, let us consider the other living things that share the planet with us. Over the past century, certified extinctions among bird and mammal species have occurred at a rate roughly 1,000 times higher than the average rate seen over the past many millions of years in these groups. There is no reason not to believe that a similar acceleration in extinction rates is taking place among the vastly more numerous, but very much less studied, insect and other invertebrate species – the small things that arguably run the world. The main causes of known extinctions have been habitat loss, overexploitation and the introduction of alien species. Often two or all three combine. However, as is clearly shown in the collection of recent studies put together by Thomas E. Lovejoy and Lee Hannah, Climate Change and Biodiversity, the effects of climate change are compounding these more direct effects of human activities. The Stern Review Report on the Economics of Climate Change – available as a download from the UK Treasury’s website or in book form as The Economics of Climate Change – notes that “Ecosystems will be particularly vulnerable to climate change, with around 15–40 per cent of species potentially facing extinction after only 2°C of warming. Ocean acidification, a direct result of rising carbon dioxide levels, will have major effects on marine ecosystems, with possible adverse consequences on fish stocks”.

Despite the growing weight of evidence of climate change, along with growing awareness of the manifold adverse consequences, there remains an active and well-funded “denial lobby”. It shares many features with the lobby that for so long denied that smoking is the major cause of lung cancer. George Monbiot’s Heat suggests that this is not an analogy, but rather a causal connection. Monbiot shows how, in 1993, Philip Morris hired a PR firm to create the illusion of a grass roots movement to fight scare stories about the dangers of passive smoking. The PR people, however, recommended that it would be better to widen the scope of “unfounded fears”, in order to suggest that worries about tobacco smoke were as chimerical as unnecessary anxieties about global warming or nuclear waste. Monbiot credits initial doubts about the reality of global warming to that PR firm: “No one could have guessed that climate change denial was first funded as a distraction technique by a tobacco company”. Whoever got things started, this is a ball which ExxonMobile picked up and ran with, shuttling lobbyists in and out of the White House as it did so. Following earlier talks and seeking to exemplify its centuries-old motto – Nullius in Verba (which roughly translates as “respect the facts”) – the Royal Society recently and unprecedentedly wrote to ExxonMobile, complaining about its funding for “organisations that have been misinforming the public about the science of climate change”, and more generally for promoting inaccurate and misleading views – specifically that scientists do not agree about the influence of human activity on rising temperatures. The plain fact is that, as shown in a recent study, of the 1,000 or so papers on the subject published in peer-reviewed scientific journals in recent years, not one denies that climate change is real, and primarily caused by us.

The distractions and misrepresentations of the well-funded denial industry are helped by the fact that, for understandable reasons, most of us find it hard to get an intuitive feeling for the real seriousness of the threat that climate change poses. For one thing, the time lags outlined above mean that the grave consequences of today’s and tomorrow’s greenhouse gas emissions will not be fully experienced for at least a couple of generations. Neither we as individuals, nor our institutions, act today on behalf of a seemingly distant future. We could call this the Easter Island Problem. It may seem unlikely that humanity, at a density of roughly ten individuals for each square kilometre of the planet, could be reshaping its geochemistry; but this question of scale takes a different shape when you realize that each year we now burn around 1 million years’ worth of fossil-fuel deposits (coal, oil, gas), so that the average inhabitant of the US annually puts 5.5 metric tonnes of carbon into the atmosphere, Western Europeans 2.2 tonnes, China 0.7 and rising, for a global average of the order of 10 tonnes for each square kilometre.

In the summer of 2005, the Royal Society took the unprecedented step of producing a brief statement affirming the scientific consensus on climate change, signed by the Science Academies of all the G8 countries – the US, Japan, Germany, France, UK, Italy, Canada and Russia – along with China, India and Brazil. The statement called on the G8 nations to “identify cost-effective steps that can be taken now to contribute to substantial and long-term reduction in net global greenhouse gas emission [and to] recognise that delayed action will increase the risk of adverse environmental effects and will likely incur a greater cost”. What are these costs? The most detailed and authoritative answer to this central question is Stern’s Economics of Climate Change. This underlines the above concerns and estimates their likely economic impacts along with the costs of actions to ameliorate them. As Stern acknowledges, such a study requires “all the economics we know, and more”. Under “business as usual” scenarios for greenhouse gas emissions, the Stern Review estimates the economic impact over the next century or so to lie in the range of a 5–7 per cent reduction of global GDP or “personal consumption”. If direct impacts on the environment and human health (sometimes called “non-market” impacts, and not usually included in such calculations, despite their obvious relevance) are included, these figures increase to 11–14 per cent or more.

The stabilization of greenhouse gas concentrations, whatever the level, requires that annual emissions be reduced to a level where they can be balanced by the Earth’s natural capacity to remove them from the atmosphere. The longer that emissions remain above this level, the higher the final stabilization level will be. The Stern Review therefore focuses on the “feasibility and costs of stabilization of greenhouse gas concentrations in the atmosphere in the range of 450–550ppm CO2”. Exploring this in detail, the review concludes that stabilization at 550ppm requires global emissions to peak in the next ten to twenty years, then fall at least 1–3 per cent each year. By 2050, this would put global emissions at around 25 per cent below current levels, even though the world economy may be three or four times larger than today (thus requiring emissions per unit of GDP to be one quarter of today’s by 2050). To achieve a much more desirable stabilization at 450ppm would require that emissions peak in the next decade, then fall 5 per cent each year, attaining 70 per cent of current levels by 2050. None of this will be easy; but the future looks very much worse if we “overshoot” and allow atmospheric greenhouse gas concentrations to rise above an eventual stabilization level in the above range. The Stern Review concludes that the economic cost of stabilization at around 450–550ppm ranges from a deficit of 5 per cent of global GDP to an uplift of 2 per cent (that is, a cost of -2 per cent), by 2050. A best guess is that the cost of “stabilization at around 550ppm of CO2 is likely to be around 1 per cent of GDP by 2050”. Set against the huge impacts of business as usual, this looks like a bargain.

But what actions should we be taking? One thing is clear: the magnitude of the problem is such that there is no single answer. Our possible actions can be usefully divided into four categories. First, we can adapt to change: stop building on flood plains; start thinking more deliberately about coastal defences and flood protection, recognizing that some areas should, in effect, be given up. Second, we can reduce wasteful consumption, in the home, marketplace and workplace: we can now design houses which consume roughly half current energy levels without significantly reducing living standards. We could, without significant loss of amenity, reduce the overpackaging of foods and other products in supermarkets and elsewhere; in the developed world today we typically spend ten calories (mostly on transport and packaging, and mainly derived from fossil fuels) to put one calorie of food on the table. Third, and necessary in the medium term while we continue to burn fossil fuels, we could capture as much as possible of the carbon dioxide emitted at source, and sequester it (burying it on land or under the seabed). Fourth, we could move more rapidly towards renewable sources of energy, which do not put greenhouse gases into the atmosphere: these include geothermal, wind, wave and water energy; solar energy (from physics-based or biology-based devices); fission (currently generating 7 per cent of all the world’s energy, and – despite its problems – surely playing a necessary role in the medium term); fusion (a realistic long-term possibility); biomass (assuming that the carbon dioxide you put into the atmosphere was carbon dioxide you took out when you grew the fuel). Some of these renewables are already being used, others are more futuristic.

Several of the books under review delve in greater detail into these actions. Most focus on satisfying energy appetites by means that either do not emit CO2 or sequester it at source. Currently around 80 per cent of the globe’s primary energy generation comes from burning fossil fuels (along with 10 per cent from biomass, much of it in a non-renewable way, 7 per cent from nuclear fission, and only 3 per cent from hydro, wind and all other). In Solar Revolution, Travis Bradford – a former fund manager – argues that solar energy will over the next few decades become the best, and also cheapest, choice for energy generation, especially for electricity. I find this prediction, based on “standard business and economic forecasting models”, a bit optimistic, but I hope he is right. Directly capturing energy from today’s sunlight has always struck me as ultimately the best substitute for using “bottled sunshine” from the fossilized plants of aeons past. But the technical problems are not trivial. Alfred W. Crosby’s Children of the Sun offers a lively account of humanity’s history, in terms of changing patterns of energy use. He ends with a survey of the likely future by seeing nuclear fission as important for our near term to be later replaced with the more user-friendly nuclear fusion. In their different ways, the books by Monbiot and Gore consider all four of the above-mentioned categories; Monbiot has more analytic depth, but the illustration-rich discussion in Gore’s book has its compensating merits. In Green to Gold, Daniel C. Esty and Andrew S. Winston show, with explicit examples from companies such as IKEA, Toyota, GE and others, that positive competitive benefits can flow from “eco-advantage”, partly from improving energy efficiency and reducing waste, but also from creating “strong brands” for a changing marketplace.

Possibly the best analysis of the feasibility of effective action is a paper recently published in Science (Volume 305, pp968–972; 2004). In “Stabilization Wedges: Solving the climate problem for the next 50 years with current technologies”, Steve Pacala and Rob Socolow present a scheme of some fifteen “wedges”, each one of which would be sufficient to prevent a billion tonnes of carbon being emitted by around 2050. All fifteen wedges are based on proven technologies, and fall into three broad categories: energy demand, energy supply and capture and sequestration of CO2 emissions. Pacala and Socolow estimate that any seven of the fifteen, if implemented promptly and strenuously, could hold emissions at around the levels of the years 2010–15.

But are the world’s nation states likely to make these commitments? Here we encounter yet another problem – and arguably the most difficult. Variously called the Tragedy of the Commons, or the Prisoner’s Dilemma, or the Free Rider Problem, it is simply put: climate change is a global problem, requiring everyone to reduce greenhouse gas emissions; but as long as others act, the “cheats” can abjure any painful change, yet enjoy the group benefit. I think the greatest and still unsolved problem in evolutionary biology, from Darwin’s day to ours, is understanding how cooperative behaviour has evolved in the face of such vulnerability to cheats prospering. And we see this in the international arena, as nations quarrel about who should act on climate change first. The problem is compounded by the fact that the rich nations, comprising about one-eighth of the world’s population, currently own a bit more than half global GDP, consuming roughly half of all industrial energy, and emitting roughly half of all CO2. Even more inequitably, the US and Europe (including Russia) account for roughly 74 per cent of the greenhouse gases currently in the atmosphere, with the rest of the world – including China, India, Africa – responsible for only one quarter. At the heart of possible solutions must be a recognition that this is everyone’s problem. Ultimately, we need a shift in cultural norms, in the mores that shape everyday behaviour. In this sense, the current collapse of sales of SUVs in the UK is perhaps encouraging.

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Robert May is a Fellow of Merton College, Oxford, and formerly Chief Scientific Adviser to the Government.