BOOKS & ARTS Clean, green fl ying machines

DOES FLYING COST THE EARTH? Science Museum, London. Until 15 November 2008.

Aircraft emissions show little sign of abating as the development of climate-friendly technologies struggles to keep pace with booming passenger numbers.

Behemoths of the fossil fuel era greet only and omit other greenhouse gases. of aircraft emissions, which leads to visitors to London’s Science Museum. But partly because of those other gases a walk-through display of the green Just inside the entrance, in Energy and their intensified effects at high technology that could power future Hall, stands Thomas Newcomen’s altitude, the IPCC estimated in 1999 planes. Both have a high gee-whiz factor: hulking steam engine, which started that air travel accounted for roughly I was delighted to learn that scientists the industrial revolution and ran on 3.5 per cent of the human-caused at Lancaster University have recruited a coal. Two galleries in, hanging between greenhouse effect in 1992, a figure network of condensation-trail spotters nineteenth-century locomotives and a predicted to climb to 5 per cent by 2050, who gather data by staring at the sky vertical stack of six classic cars, one of though with large uncertainty. More daily, and to inspect models of nifty the world’s first commercial airliners recently, the UK’s Royal Commission futuristic jets. glowers from the ceiling. on Environmental Pollution suggested In exploring such technologies, the It is a powerful symbol of the 5 per cent should be revised to exhibition makes inspired use of facts and modernity — its iconic status surely one 6–10 per cent. fi gures. Each innovation, from lightweight reason the mere mention of composite materials to hydrogen fuel, slashing emissions from is rated in fi ve categories: emission air travel draws cuts, timescale to deployment, so much anxiety. cost, eff ort Aviation was the fi rst required, and economic sector to have eff ect on passenger its greenhouse emissions and experience. Removing promised technological innovations rivets from plane surfaces, for example, scrutinized in a special report of the can be done immediately at low cost but Intergovernmental Panel on Climate hardly cuts emissions. A new open-rotor Change (IPCC). Now the Science engine yields deeper cuts but makes Museum takes up the same subject for The 1935 Lockheed Electra (left), an early commercial fl ights unpleasantly noisy and slow. Like one of the earliest in a series of climate airliner featuring a then-cutting-edge aluminium-alloy those of baseball cards or characters in change-related exhibitions. skin, overlooks the entrance to the Science Museum’s role-playing games, the statistics — listed So how bad is aviation for the planet? exhibition of green aviation technology for on cards that can be picked up and passed Th e show, Does Flying Cost the Earth?, the twenty-fi rst century. Highly aerodynamic around — are addictive to compare and starts by highlighting the importance of ‘blended-wing’ plane designs (right) may be seen analyze. Two important possible advances perspective in addressing this question. on runways in 25 years. (Image credit: Left, Science fall outside the scope of this green-tech Th ree pie charts present the case. Museum; Right, Jennie Hills/Science Museum. ) survey, however: better air traffi c control Concerned that your carbon consumption to cut emissions, and supersonic jets that is out of control? Th en worry about air would greatly worsen aviation’s impacts. travel: taking about two fl ights a year Th e impact of aircraft on our future A rudimentary video game near the costs the average Briton 12 per cent of her climate will be determined by, among exhibition’s end sums up the situation at individual carbon pie. Or worried about other factors, the combined warming a visceral level. As air traffic increases in how governments propose to cut national eff ects of all greenhouse gases. Quoting the future, players try to keep emissions and global emissions? Planes spew percentages of carbon dioxide alone down by installing green technologies 6 per cent of the UK’s carbon dioxide, but makes the numbers more digestible, in the hordes of planes multiplying on a only 2 per cent of the world’s. By 2050, perhaps — it’s the count most familiar touch-screen sky — an upgrade carried that 2 per cent is expected to creep up to to eco-conscious apportioners of pie out by poking the icons to change their about 3 per cent. slices — but far less meaningful. color and shape. The difficulty of the task This is where the exhibit first Stronger set-pieces follow. After lends a crude but memorable caveat to makes an inevitable compromise on an explanation of the greenhouse the exhibit’s technological optimism. thoroughness. Captions fail to make it effect comes an excellent computer Finally, the exhibition ventures into clear that the pies show carbon dioxide presentation on research into the impacts activism, inviting visitors to pledge to

91 nature reports | VOL 2 | JULY 2008 | www.nature.com/reports/climatechange BOOKS & ARTS do their share against aviation emissions earlier on. Make a diff erence between Published online: 12 June 2008 by supporting green policy, taking fewer what — 2 and 3 per cent of global fl ights or buying carbon off sets. A video emissions? By its end, the exhibit has doi:10.1038/climate.2008.58 display shows how many have taken each off ered some engaging glimpses of pledge, a great way to make people feel aviation’s vanguard for climate science Anna Barnett part of a concerned community. But the and engineering, but it hasn’t satisfyingly Anna Barnett is assistant editor feel-good message that “collectively ... we answered the question in its title. It has and copy editor of Nature Reports can all make a diff erence” is undermined the excuse that scientists and engineers Climate Change. by the incomplete treatment of impacts are still working out that answer. e-mail: [email protected] Full of hot air

AN APPEAL TO REASON: A COOL LOOK AT GLOBAL WARMING

by Duckworth Overlook: April 2008. 149pp. £9.99

Far from being cool and rational, Nigel Lawson’s offering on climate change is largely one of misleading messages.

Although there remains uncertainty taxation over carbon trading, for example, since the mid-20th century is very in many aspects of climate science, as and gives some insights into how a likely due to the observed increase in all science, over the past few years deal on mitigating warming involving in anthropogenic greenhouse gas an overwhelming and well-founded both developed and developing nations concentrations.” He does this, not with acceptance has emerged, not only in the might work, his book is largely one of any analysis of his own, but by listing scientifi c community, but among the misleading messages. some of the sources of uncertainty that are general public and in political arenas, Th e fi rst of these is his questioning in any case thoroughly addressed by the that human activity, and in particular the of the reality of human-caused global IPCC. One wonders whether he has in fact burning of fossil fuels, is warming the warming itself. Early in the book, showing read the panel’s reports. planet. Far from the debate being over, with a surprising ignorance of elementary Moving on from his critique of the this awareness the discourse on climate statistical analysis, Lawson takes the science of climate change, Lawson argues change has largely moved from one of record of global average temperature in that even if global average temperature questioning the science to disputing what the fi rst seven years of this century as increased by about 3 °C, such warming ought to be done about the problem. evidence that the scientists must have it would be trivial, and even largely Into this arena enters An Appeal wrong. By themselves, these years show benefi cial. But given that the diff erence to Reason by Nigel Lawson, former no signifi cant increase in temperature, in temperature between the middle Chancellor of the UK Exchequer, who but they are warmer on average by almost of an ice age and the warm periods in makes a call for “a cool look at global 0.1 °C than the previous seven years. Even between ice ages is only 5 or 6 °C, an warming”. Journeying through the science, a casual inspection of the global record increase of 3 °C, occurring over much politics, economics and ethics of climate from 1970 shows two things: fi rst a clear shorter time periods — on the scale of change, Lawson challenges head-on the trend of about a 0.5 °C increase over the centuries rather than millennia — is far aspects of conventional wisdom that he past 30 years, and second a substantial from inconsequential. And although they believes to be fl awed, and shines a light on year-to-year variability of the kind that is receive extensive coverage in the IPCC what he interprets as spinning of rhetoric well known to climatologists and has been reports, Lawson completely ignores some by the media and politicians. attributed to phases of the El Niño/La of the most serious impacts of global Promised as a “rare breath of Niña phenomenon, a regular feature of the warming: namely the fl oods and droughts intellectual rigour” and a “hard headed Pacifi c climate. that are expected to become more examination of the realities” of climate Lawson then challenges the frequent and more severe with even small change, this off ering is neither cool nor carefully worded conclusion of the UN’s rises in temperature. rational. Although Lawson makes some Intergovernmental Panel on Climate Considering the potential for more worthwhile critiques of energy policy, Change that “most of the observed climate extremes and sea level rise in the presenting an argument for carbon increase in global average temperatures future, there are likely to be hundreds of nature reports climate change | VOL 2 | JULY 2008 | www.nature.com/reports/climatechange 92 BOOKS & ARTS

millions of refugees from the world’s most mid-century. And because carbon dioxide Lawson, with rhetorical fl ourishes, aff ected nations. Where could those people emitted into the atmosphere remains there addresses those of us who see more than a go in our increasingly crowded world? on average for around 100 years, there is ‘grain of truth’ in global warming and wish to Lawson denies that there is any problem. an urgent need to begin reductions now. take responsible action towards its mitigation. He repeats a number of times his summary Lawson writes this off as being diffi cult, He lumps us together with a motley mixture of the damage as the diff erence between inconvenient and very costly. But both of those he labels as eco-fundamentalists people in the developing world being 8.5 the International Energy Agency and or anti-globalization lobbyists. All of us are times better off than they are now and the Shell have recently presented scenarios connected with what he calls a “mountain 9.5 times improvement that they would see of changes in energy generation and use of nonsense” for which it appears the IPCC in the absence of global warming. Sleight by 2050 that show it would be feasible to is responsible. May I urge Lord Lawson of hand with gross numbers of possible move substantially towards achieving the to espouse the cool reason and rigour for economic growth must not be allowed emissions reductions required. How great, which he appears to be campaigning and to hide the magnitude of the very real then, is the cost? Th e on the respectfully suggest that he might begin with problems. Th e 2007 IPCC report makes it Economics of Climate Change indicates a course of reading of the IPCC reports. clear that the anticipated impacts of global that if we act quickly, this could be as little warming will lead to tens or hundreds as a few per cent of GDP by 2050. Crucially, Published online: 19 June 2008 of millions of people suff ering loss of delayed action will increase the price tag, resources, livelihoods and land. with the cost of doing nothing and paying doi:10.1038/climate.2008.60 But even if such impacts were likely, to adapt to change much greater than we cannot aff ord to address them, that of early mitigation. Again, Lawson Sir John Houghton says Lawson. To stabilize atmospheric begs to diff er, arguing that the fi nancial Sir John Houghton CBE, FRS is an Honorary concentrations of greenhouse gases during burden of reducing emissions sharply Scientist at the Met Offi ce Hadley Centre this century, emissions would have to be would simply be unjustifi ed in the face of in the UK. substantially reduced from today’s levels by scientifi c uncertainty. e-mail: [email protected]

An informal forum facilitating lively and informative discussion on climate science and wider implications of global warming. “ Join in the debate! http://blogs.nature.com/ “ climatefeedback 93 20408-04 Climate feedback HPH.indd 1 ””nature reports climate change | VOL 2 | JULY 2008 | www.nature.com/reports/climatechange18/6/08 10:04:03