Monday, December 8, 2014

Why the risks of climate change have been engineered away

One of the greater challenges we engineers face is telling our clients that their dream project doesn’t work.  If it costs too much, they usually accept our advice with ill grace.  Sometimes, it is technically impossible. Then they have great difficulty in believing us.  For instance, few will accept our advice that the ideal of creating a low carbon world within our lifetimes is probably not achievable.

The evidence that a low carbon world within our lifetimes is an unachievable dream is clear.  In 1998, the then developed nations signed the Kyoto Protocol, which placed legally binding commitments on them to reduce their emissions below 1990 levels. Global emissions in 1990 were 22.6 billion tons of carbon dioxide (CO2).  Fossil fuels made up 88% of the primary energy supply. In 2012, when the first Kyoto commitment period came to an end, global emissions were 34.5 billion tons, over half as much again as in 1990, and fossil fuels made up 87% of the primary energy.  So much for legally binding commitments!

Of course, the developing nations did not foresee the rapid development of China.  That put paid to the Kyoto ambitions.  Recently, there has been much cheering about China’s offer to start reducing its emissions after 2030.  It is perhaps not as encouraging as at first appears. Today China emits nearly 10 billion tons; business-as-usual until 2030 will see its emissions rise to nearly 18 billion tons.

And if the development of China was overlooked, then the possible similar surge in India’s emissions seems to have been forgotten. India has rejected outright any similar offer to reduce its future emissions, citing the need to develop its economy before it can take such a step. Today India emits about 2 billion tons; by 2030 it is likely to be emitting over 5 billion, and rising rapidly.

So the dream appears unachievable.  The question is then whether it will turn into a nightmare.  There are many who claim that a higher carbon world will be wracked by disaster. In this scenario, the seas will rise, storms will rage, drought will strike, and the biosphere will disappear. These are the predictions of many climate models. While all agree that the models are not very good, the question has to be asked – Suppose the models are right?

Back to the engineers.  Today, humanity depends on us engineers to provide the defences against the seas, floods, droughts and even fires and earthquakes.  Generally we do quite a good job.  Many people stay warm and dry, have enough to eat and drink, and rarely experience the disaster of fires or earthquakes.  Of course, our solutions come with a cost, and there are some who are still trapped in poverty whom we have not yet found ways to save.  But this is largely a social problem. We engineers recognise that while we can make a contribution, poverty is not something we alone can solve.

If this is the state of the world today, then the disaster scenario predicted by the climate models implies that the defences we engineers have built will be found wanting.  In this case, to address the risks, we need to enquire where the existing defences may be too weak to withstand a fiercer onslaught.   

Will the seas rise and drown our cities?  The Dutch have done a good job of teaching the world how to live normally below sea level, so that is not an insuperable problem.  Will there be greater floods than ever known?  Generally engineers design for a one-in-a-hundred-year flood. If we start to get more than that, we should have some time to improve the design to cope with the new one-in-a-hundred.  Will droughts strike with greater frequency and severity?  Our water supplies are already reasonably robust, and over half our water is used quite inefficiently for agriculture. It seems likely that we could withstand more extensive drought, particularly if supplies can be boosted.

This is the basic message that seems to have been lost in the panic about the risks of climate change – we already have a high degree of resilience against the climate, thanks to generations of engineers working in the service of humanity.  That resilience needs maintenance if it is to continue to provide the desired level of protection. It may need reinforcement if the climate should become more extreme.  But the risks presented by climate change are by no means insuperable. The costs are most unlikely to be as excessive as some doomsayers would have us believe.

Moreover, some of the benefits of more carbon dioxide in the atmosphere should not be overlooked.  Satellite images show the world greening and deserts retreating. Many European greenhouses are being controlled at over 1000 parts per million CO2, two-and-a-half times atmospheric levels. This has been found to boost vegetable and fruit production very significantly.

So the risks that climate change may prove unduly destructive are almost certainly overstated, while the supposed driver of climate change, carbon dioxide, is proving beneficial to life. The proposed “solutions” to climate change, such as carbon taxes, can now be seen to be the chimeras they really are.

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