Today I’ve been at Parliament in London, at an event sponsored by the Parliamentary Office of Science and Technology to launch the second phase of the Environmental Nanoscience Initiative. This is a joint UK-USA research program led by the UK’s Natural Environment Research Agency and the USA’s Environmental Protection Agency. This is a very welcome initiative to give some more focus to existing efforts to quantify possible detrimental effects of engineered nanoparticles on the environment. It’s important to put more effort into filling gaps in our knowledge about what happens to nanoparticles when they enter the environment and start entering ecosystems, but equally it’s important not to forget that a major motivation for doing research in nanotechnology in the first place is for its potential to ameliorate the very serious environmental problems the world now faces. So I was very pleased to be asked to give a talk at the event to highlight some of the positive ways that nanotechnology could benefit the environment. Here are some of the key points I tried to make.
Firstly, we should ask why we need new technology at all. There is a view (eloquently expressed, for example, in Bill McKibben’s book “Enough”) that our lives in the West are comfortable enough, the technology we have now is enough to satisfy our needs without any more gadgets, and that the new technologies coming along – such as biotechnology, nanotechnology, robotics and neuro-technology – are so powerful and have such potential to cause harm that we should consciously relinquish them.
This argument is seductive to some, but it’s profoundly wrong. Currently the world supports more than six billion people; by the middle of the century that number may be starting to plateau out, perhaps between 8 and 10 billion people. It is technology that allows the planet to support these numbers; to give just one instance, our food supplies depend on the Haber-Bosch process, which uses fossil fuel energy to fix nitrogen to use in artificial fertilizers. It’s estimated that without Haber-Bosch nitrogen, more than half the world’s population would starve, even if everyone adopted a minimal, vegetarian diet. So we are existentially dependent on technology – but the technology we depend on isn’t sustainable. To escape from this bind, we must develop new, and more sustainable, technologies.
Energy is at the heart of all these issues; the availability of cheap and concentrated energy is what underlies our prosperity, and as the world’s population grows and becomes more prosperous, demand for energy will grow. It is important to appreciate the scale of these needs, which are measured in 10′s of terawatts (remember that a terawatt is a thousand gigawatts, with a gigawatt being the scale of a large coal-fired or nuclear power station). Currently the sources of this energy are dominated by fossil fuels, and it is the relentless growth of fossil fuel energy since the late 18th century that has directly led to the rise in atmospheric carbon dioxide concentrations. This rise, together with other greenhouse gases, is leading to climate change, which in turn will directly lead to other problems, such as pressure on clean water supplies and growing insecurity of food supplies. It is this background which sets the agenda for the new technologies we need.
At the moment we don’t know for certain which of the many new technologies being developed to address these problems will work, either technically or socio-economically, so we need to pursue many different avenues, rather than imagining that some single solution will deliver us. Nanotechnology is at the heart of many of these potential solutions, in the broad areas of sustainable energy production, storage and distribution, in energy conservation, clean water, and environmental remediation. Let me focus on a couple of examples.
It’s well known that the energy we use is a small fraction of the total amount of energy arriving on the earth from the sun; in principle, solar energy could provide for all our energy needs. The problems are ones of cost and scale. Even in cloudy Britain, if we could cover every roof with solar cells we’d end up with a significant fraction of the 42.5 GW which represents the average rate of electricity use in the UK. We don’t do this, firstly because it would be too expensive, and secondly because the total world output of solar cells, at about 2 GW a year, is a couple of orders of magnitude too small. A variety of nanotechnology enabled potential solutions exist; for example plastic solar cells offer the possibility of using ultra-cheap, large area processing technologies to make solar cells on a very large scale. This is the area supported by EPSRC’s first nanotechnology grand challenge.
It’s important to recognise, though, that all these technologies still have major technical barriers to overcome; they are not going to come to market tomorrow. In the meantime, the continued large scale use of fossil fuels looks inevitable, so the idea of the need to mitigate their impact by carbon capture and storage is becoming increasingly compelling to politicians and policy-makers. This technology is do-able today, but the costs are frightening. Carbon capture and storage increases the price of coal-derived electricity by between 43% and 91%; this is a pure overhead. Nanotechnologies, in the form of new membranes and sorbents could reduce this. Another contribution would be finding a use for carbon dioxide, perhaps using photocatalytic reduction to convert water and CO2 into hydrocarbons and methanol, which could be used as transport fuels or chemical feedstocks. Carbon capture and utilization is the general area of the 3rd nanotechnology grand challenge, whose call for proposals is open now.
How can we make sure that our proposed innovations are responsible? The idea of the “precautionary principle” is one that is often invoked in discussions of nanotechnology, but there are aspects of this notion which make me very uncomfortable. Certainly, we can all agree that we don’t want to implement “solutions” that bring there own, worse, problems. The potential impacts of any new technology are necessarily uncertain. But on the other hand, we know that there are near-certain negative consequences of failing to act. Not to actively seek new technologies is itself a decision that has impacts and consequences of its own, and in the situation we are now in these consequences are likely to be very bad ones.
Responsible innovation, then, means that we must speed up research to fill the knowledge gaps and reduce uncertainty; this is the role of the Environmental Nanotechnology Initiative. We need to direct our search for new technologies in areas of societal need, where public support is assured by a broad consensus about the desirability of the goals. This means increasing our efforts in the area of public engagement, and ensuring a direct connection between that public engagement and decisions about research priorities. We need to recognise that there will always be uncertainty about the actual impacts of new technologies, but we should do our best to choose directions that we won’t regret, even if things don’t turn out the way we first imagined.
To sum up, nanotechnologies, responsibly implemented, are part of the solution for our environmental difficulties.