An Interesting Idea

by Andrew Teller

Nobody denies global warming nowadays, but some scientists do question its causation by man-made carbon dioxide (CO₂) emissions. In a nutshell, their analysis goes like this¹:

The two most important greenhouse gases are by far water vapour and CO₂. The former is at least 27 times more abundant than the latter and has an infrared absorption power eight times as high, which explains why the responsibility for greenhouse effect rests overwhelmingly with water vapour. A detailed calculation shows that the share of responsibility is 99.4% for water vapour and 0.45% only for CO₂.

The atmosphere content of CO₂ is controlled by two “sinks”, vegetation (terrestrial and marine) and the oceans, which contain 50 – 60 times more CO₂ than air. When the average temperature of the earth increases, the solubility of CO₂ in seawater decreases and a slight degassing of the oceans takes place, thereby increasing the CO₂ content of the atmosphere. The increase in the CO₂ content of the atmosphere would, therefore, be a consequence of global warming and not its cause, as is widely held.

Anthropogenic emissions of carbon dioxide represent less than 1% of the carbon dioxide content of the atmosphere. Consequently, the contribution of anthropogenic emissions amounts to less than 1% of 0.45%, i.e. 45 parts per million which is completely negligible.

To a layman such as me, the above views do not seem to contain obvious shortcomings. They are, however, in sharp opposition with those of the International Panel on Climate Change (IPCC), the UN-appointed body investigating the matter. My purpose is not to use this column to spark an argument which, as has been seen in the past, can easily turn sour. Let me just point out that the resolution of this difference is in principle very simple: either the sceptics’ analysis is beside the point or it isn’t. In the first case, this is worth demonstrating by those upholding the official position; the IPCC theory can only gain from being seen as capable of overcoming objections based on scientific reasoning. In the second case, the said objections should be taken into account as a matter of urgency, given the magnitude of the measures envisaged to combat a climatic evolution over which we would actually have no control whatsoever.

I would rather reflect on the consequences for nuclear energy of the possible conclusion that, after all, human activities play no meaningful part in global warming. Would such a conclusion deprive nuclear energy, as a CO₂-free source, of its raison d’être? The answer is clearly no, because global warming is but one piece of the puzzle humankind must solve. It is worth recalling the other elements from time to time, lest we lose track of an important part of the big picture. So let’s review the other main reasons why nuclear must be a part of the solution, all climatic concerns set aside.

Diversification: this conceptcovers two equally important aspects of security of supply.

Fuel procurement: the different sources of energy we can consider are available in different quantities in different parts of the world. Uranium contributes to the diversification of many countries’ energy sources and therefore enhances security of supply.

Avoidance of production bottlenecks: recent events have made it painfully clear that production capacities cannot be rapidly adjusted to growing needs without causing disruption somewhere in the economy. This has been the case with the diversion of corn crops to the production of biofuels that triggered a sharp price increase at the beginning of 2008. The spectacular increase of the cost of petrol is likewise ascribable to some extent to a lack of refining capacity. Sharing the burden of building the needed generation capacity between different technologies can only reduce the threat of production bottlenecks.

Concentration: this feature is all too often overlooked. Nuclear fuel is a highly concentrated source of energy: a few lorries are enough to keep a nuclear reactor running for a whole year. A coal-fired unit of the same power would require many more lorries every day in order to fulfil its purpose. This might not seem very important to many, but not to those who are aware of motorways crowded by uninterrupted queues of lorries, e.g. in the Beijing area, or of saturated railway networks striving to keep coal-fired power stations in operation. The high concentration of nuclear fuel is admittedly the cause of the high toxicity of its waste, but this is no reason for ignoring its positive aspect: every cloud is entitled to its silver lining.

Additional resource: being relieved of the need to limit CO₂ emissions does not relieve mankind from the duty to evolve to a more sustainable way of life. The predictable decrease in fossil reserves has finally started to sink in the collective awareness. Most renewable energy sources are ill-suited to base load power generation. Humankind will need decades to adjust to the new conditions through an assortment of technical innovations and societal measures. Renewing an automobile fleet takes around fifteen years in a healthy economy. Replacing the existing housing stock by new builds meeting the current isolation criteria can take a century. Over such time scales, nuclear energy can help to smooth out the transition and provide a much needed breathing space, all the more so that fuel recycling opens the prospect of vastly increased reserves.

Competitiveness: it is difficult to provide reliable figures at a time when raw materials and fuels undergo rapid changes. Our best bet is however that their prices will keep increasing and (perhaps) stabilise at levels previously unheard of. In terms of consumption of steel and concrete per MWh, nuclear power plants are rather well positioned: not as well as gas-fired units, roughly equivalent to coal-fired plants and much better than wind turbines. There are therefore good reasons to expect competitive prices for nuclear power plants, as witnessed by the renewed interest of a growing number of utilities everywhere in the world.

Pointing out the contribution of nuclear energy to the fight against global warming is justified given the state-of-the-art knowledge regarding climate change. Doing it too narrowly would not only be a strategic mistake, it would first and foremost ignore the very basic fact that no energy source can provide a universal answer to humankind’s future needs nor be excluded at no cost from the portfolio of available options.

¹ If you want to know more about the views of those who question the role of anthropogenic CO₂ emissions, www.globalwarmingheartland.org is one of many starting points available.

The case for nuclear energy is not solely linked to global warming

by Andrew Teller