The Oxford Science Lecture Series

PROFESSOR SUE ROAF and DR ANNE WHELDON

" What will Life be Like in 2050?"

University Museum, Oxford, 21st June 2000

A lecture with this title was given jointly by Dr. Anne Wheldon (Engineering Department, University of Reading) and Professor Sue Roaf (Department of Architecture, Oxford Brookes University) on June 21 2000, as the 14th in our series of Oxford Science Lectures. From their complementary approaches to the common problem of the dwindling traditional energy resources in the Earth, they created a unique antiphon of fact versus feature, the physics of energy sources and their sustainability flavoured with the human and demographic statistics of supply and want (rather than need), weaving them forcefully into a presentation that was, to the ecologically-minded, as disturbing as it was fascinating.

The evolution of the civilization of mankind has parallelled the procurement and harnessing of energy of ever-increasing complexity. The acquisition of mechanical power is measured not just in economic terms but in possibilities and achievements, most obviously in high-speed travel and space exploration. Global statistics show that fossil fuels (oil, gas and coal) represent about 80% of the sources of energy currently being tapped, the remainder being predominantly biomass products plus a small fraction from renewable sources such as solar, wind, hydro- and geothermal energy. There were no surprises in the world distribution of users, North America being the most energy-hungry region and Western Europe second; life in Eastern Europe is generally less energy-dependent, and that in the rest of the world relatively low, though gradually growing - as in China. Yet it is the poorest nations that are making relatively the most advanced in their uses of low-cost renewable energy sources such as biomass products.

Energy resources do not necessarily occur where they are most wanted. While coal occurs fairly widely throughout the world and gas rather less so, oil is of course highly concentrated in Middle East countries. Remoteness from oil sites implies significant shipping costs (i.e. energy expenditure), and since there are now insufficient supplies to meet projected world demand the economics have led to an inflated pricing system, exacerbated by the use of oil as a political weapon as well as a vital trade product.

While the limited nature of present, known deposits of fossil fuels presents problems for the economist, the ecologist experiences worse fears about the environmental impact of the use of traditional energy sources. The end product of fossil-fuel burning is carbon dioxide, and all the statistics point to the conclusion that increases in the production of carbon dioxide have already had important effects, some of them irreversible, upon planet Earth. The changes mapped by temperature and weather monitoring in the last century are monotonic and persistent, causing very real disquiet in low-lying countries and islands prone to flooding, while cities have to expect increasingly warmer centres (the "city island" effect), exacerbating air-pollutant problems and associated respiratory diseases. Even though rises in air and sea temperature might be welcomed by chilly mortals, organisms such as coral are dying off, and plant diseases which have usually been adequately regulated by frosts are now noticeably more prolific.

Concerns like these are now beginning to drive proactive measures, all with the common aim of increasing radically the use of renewable energy sources. Every partial change from conventional (unrenewable) fossil fuels would help to reduce the upward gradient of energy demand to meet man's increasing wants and expectations, while each small curtailment in man's aspiration towards 'higher' standards of living would help to postpone the crunch. The model proposed by Shell Oil gives in detail the targets to be met if projected trends are to be moderated to a sustainable level. The purist would point out that energy sources such as sunshine, wind and geothermal heat are not infinitely renewable on astronomical time-scales. However, they do not leave ecologically disastrous residues; moreover, since renewable energy resources are potentially sufficient to meet demands when fossil fuels run out, they can provide a fantastic answer in face of the relatively imminent exhaustion of fossil-fuel deposits. Increases in nuclear energy provides only a partial solution to the disappearing sources of fossil fuels, owing to the potentially serious hazards of their end-products.

Some countries are already building programmes to experiment in replacing traditional energy sources with renewable ones: a 'solar city' near Amsterdam, 10,000 'photovoltaic' houses in German... And each year some 30% more renewable-energy equipment is sold compared to the previous year. Response in the UK has been characteristically rather muted, but of the 10 photovoltaic homes it now boasts one which was designed by Professor Roaf, who led the audience on a virtual tour to explain not only the many energy-saving features but also its relatively normal visual appearance. Although one swallow does not of course make a summer, personal example is strongly influential, especially if backed up by suitable financial incentives to extend those already offered for home insulation schemes.

The speakers argued strongly that the Beijing Summit, which committed countries to a 12% reduction in carbon dioxide emissions by the year 2010, was not sufficiently ambitious to achieve the reverses necessary to avoid the projected disasters of 2050, and a new report from the Royal Commission on Environmental Pollution, assessing the likely impact of continuing disdain of the environmental signals, took as its target a figure of 60% reduction by 2050. The list of measures that would have to be adopted in achieving that target did not make comfortable reading; for instance, a requirement to stabilise energy demands at 1998 levels would imply much greater use of public transport (which is more energy-efficient than private cars), reductions in personal mobility by allowing (or requiring) people to work from home, the manufacture and installation of large quantities of solar panels, the construction of river barrages and the erection of many acres of wind farms.

Inasmuch as the life of the Sun, the orbit of the Moon and the mass of Earth can be regarded as fixed, energy from sunshine, waves and geothermal heat can be harnessed as widely and as often as we want without risk of wearing down the supply; the only likely limits are the number (and cost) of manufacturing and installing solar panels and wind machines, and of burying heat exchangers in the earth, river or stream. Ecologists may meet head-on over concerns about changes to the landscape, and local councils may have sore heads with the implications of changing demographic habits, but in practice the final choice may be between a countryside rather full of wind-turbines and hydroelectric pipes, or no countryside at all. You didn't have to be born after 1960 to be affected by the power of this message.

Elizabeth Griffin (Oxford AWiSE) .