The tragedy at Fukushima one year ago has had a hugely varied impact on public opinion and energy policy around the world. In our polling immediately afterwards, the effect seemed likely to be significant: a quarter of those who opposed nuclear power in the 24 countries surveyed said they did so because of Fukushima.
One year on, sitting in London or New York, it's easy to think that was a blip. Our tracking surveys in the UK, for example, show that while support for nuclear power did fall in mid-2011, it has bounced back to pre-Fukushima levels, and has even been slightly strengthened.
But that's not the whole picture: looking back in a few years time Fukushima is likely to be seen as a significant tipping point for some countries. In Germany and Italy the disaster galvanised already negative views, and key public votes or policy decisions were taken in the aftermath. An Italian referendum emphatically rejected nuclear power, and the German government closed several plants, with all to be shut by 2022.
Fukushima's main effect on energy policy then has been to largely reinforce existing views, and push those already sceptical countries into decisive action.
It might therefore be seen as a policy area that is public opinion and protest led - but in many ways, the opposite is true. When we plot reliance on nuclear power against public support for nuclear power, the pattern is all over the place. Some countries with the greatest reliance on nuclear have the lowest public support for it - most notably France. This is sometimes portrayed as a result of governments being in the pockets of nuclear lobbies - but the explanation is much less clear-cut than that.
As with all aspects of opinions and policy on energy, the drivers are as varied as the social, political and economic contexts of different countries. It is also partly because people themselves are balancing competing concerns.
Five factors come out consistently as the key issues on energy for the public: ahead of everything is cost, then four concerns - CO2 emissions, security of supply or dependence on other countries, the threat of nuclear disasters and the need for investment in renewables - all vie for the next most important.
But even here the challenge for policy-makers is that it's not actual dependency, reliability of renewable sources or real risks of nuclear disaster that drives public opinion, it is perceptions of them. Just to take the example of dependency on other countries, you might expect that high dependency countries would support nuclear more, as dependency is something people would generally like to avoid and nuclear power supply is at least within national control.
But in fact we see the opposite relationship, where low dependency countries like Britain and Sweden actually have relatively high support for nuclear power. This will again be explained by the differences in local context, which in Britain's case will include that we feel much more dependent than we actually are: queues at petrol stations and streetlights being turned off have left scars.
The assumption in these sorts of circumstances is that emotion will therefore play a leading role in forming views - that eye-catching disasters will lead to significant change, and the closer we feel to the tragedy, the more impact it will have. Elements of the reaction to Fukushima show this is not the case. In many parts of Asia there is still strong support for nuclear, and many developing countries, including China, are pushing on with dozens of new reactors. The general public do not perform detailed risk calculations when coming to their views, but neither do they just react to one event - particularly when their day-to-day needs for cheaper, more reliable energy run counter.
The choices on nuclear are often portrayed as a battle between these needs and fears. This is true, but it applies to energy more generally, not just nuclear. The fear is not just of a disaster such as Fukushima, it's also of the impact on global warming of CO2 emissions and the failure of renewable sources - and our assessment of these risks are all based on partial and contested information. No wonder global opinion is confused.
For more on global public opinion on energy policy, see After Fukushima - a new report from Ipsos Social Research Institute.Suggest a correction