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Issue 8 |
Professor John Beddington is Chief Scientific Adviser to the Government and Head of the Government Office for Science. As he said, he is not an engineer, but a population biologist from Imperial College. He confessed that his new job, to advise the Government on science generally, would be an impossible one but for the presence of the other Chief Scientific Advisers that most Government Departments had now appointed (the Treasury excepted!), and their supporting staffs, who between them included several engineers, social scientists and natural scientists, with whom he was in regular contact. And there were the research councils and engineering and scientific institutions which he could also consult.
He then showed us a slide listing eleven global challenges to the 21st century, but explained that he did not propose to deal with all of them!
1. Population growth and urbanisation
These were particularly critical in Asia and Africa, less so in the rest of the world. Total world population was growing at six million per month, and was predicted to reach about 8.3 billion by 2030. But all of this growth was likely to take place in urban population, while the rural population actually declined. This growth was likely to lead to famine and disease. But in most of the world prosperity would increase, in that far more people would have an improved standard of living. There would thus be a much increased demand for a diet richer in meat and dairy products, for more travel, and more energy etc. Food production and energy demand worldwide were both predicted to rise 50% by 2030, much more than the population increase.
2. Water
One third of the world's population faces water shortages already, and this will certainly increase. About two-thirds of the use of fresh water now is by agriculture, mainly by rather inefficient "peasant agriculture". Shortages are going to lead to such use being "priced", leading to a greater pressure on people to leave agriculture and move to the cities. He defined the vulnerable parts of the world in this respect as those using more than 40% of the available fresh water (the rest either evaporating or running into the sea). These regions are going to increase, particularly with the rising temperatures from climate change, to include most of North and South Africa, the Middle East and India. Steven Chu, Head of the US Department of Energy, has predicted that even in California, agriculture may have to cease in 25 years.
3. Climate Change
A 2°C rise in average temperature is now unavoidable whatever we do, and it will be 4°C if we fail to cut our CO2 emissions by 40%. Crop yields will fall in many areas, though they may rise in higher latitudes. The Arctic may well become ice-free in the summer, which would open up opportunities to exploit its resources (and to squabble about them!). But melting glaciers and ice-caps will raise the sea level, and tundra regions may start to give off methane, thereby enhancing the greenhouse effect. And much else will occur too.
A modest average temperature rise of about 2°C in 2003 led to an estimated 35,000 deaths in Northern Europe. By 2040 such temperatures (40°C) will be the summer norm. The London Underground could well become intolerable, though Scotland might perhaps become cooler (and wetter!).
4. Ocean Acidification
The pH of the oceans is believed to have hovered around 8.1-8.2 for the last 25 million years, but if much of our increased CO2 emissions were to dissolve in them, they could become seriously acidic, e.g. a pH of 7.7. The consequences for eco-systems and food supplies could be very serious, though, as the lecturer admitted, our knowledge here is very sketchy. It is thought that the last time the oceans became that acidic, 50% of the organisms in them became extinct. But that was a very long time ago.
5. Conflicts
By 2030 (the lecturer's chosen cut-off date) we are going to need 50% more food, 50% more energy (from clean sources), 30% more fresh water, and we have to adapt to climate change. Only last year, when cereal prices suddenly rose by 200%, there were riots in e.g. Africa, Bangladesh and the West Indies. There will be conflicts over water in the future, one hopes not between two nuclear powers! When some areas become uninhabitable, either being flooded by rising seas or becoming too hot and dry to live in, the inhabitants will want to move elsewhere. The inhabitants of more favoured lands are unlikely to welcome their arrival.
6. Getting our greenhouse gas emissions down
The UK Climate change Committee has recommended that, as compared with 2005, greenhouse gas emissions should come down by 80% by 2050, and by 21% or 31% (depending on international agreements) by 2020. Electricity generation will have to be virtually carbon-free. The most obvious ways to achieve that are nuclear, wind and CCS (carbon capture and storage), this latter still being in the development stage. Worldwide, CCS is particularly important, since coal is plentiful and cheap in developing countries like China, India and South Africa. Should nuclear fusion turn out to be practical, it will be extremely valuable, and the potential rewards from it justify almost any conceivable level of research investment.
Among other possible energy sources (tidal power etc.), biofuels could be very valuable, both in reducing the use of fossil fuels for transport and in increased energy security for many countries. But it has to be done properly, not on land that could more usefully grow other things. The Brazilian approach with sugar-cane is better than the US one using grain feedstock. But whatever it is, the feedstock has to be transported in bulk, and Brazil's transport network is being found to be somewhat lacking.
Water will have to be used much more efficiently, especially in agriculture, for example by using sensors to give each plant the water it needs, rather than just spraying it indiscriminately and wastefully over the whole field. African agriculture in particular could benefit from such techniques.
To maintain adequate food supplies, the technology of genetic modification is going to be essential. Most of the world is quite happy to use it, but Europe has some irrational prejudice against it that it is going to have to lose. For example, a type of rust that can destroy a wheat crop is gradually coming here from the Middle East. There is no cure for it, but a genetically-modified wheat could be resistant to it. Productivity can be increased in other ways too. We were given an illustration from Brazil, where they now get two crops a year, with the machines planting the second crop following only an hour behind those harvesting the first one.
All these problems are interconnected, and need to be tackled together.
There is still lots of uncertainty about the detailed consequences of climate change. For the UK regions, we can predict with reasonable confidence up to about 2030, but after that? And elsewhere, how much will the flow of the rivers Zambezi and Limpopo be reduced? Will the Sahelian drought break? Will we get more frequent El Niños? And so on. We do not know.
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