Last week the EU’s effective political leader Mrs Merkel said she was worried by the big gap between the views of the establishment who see climate change as the gravest threat facing us and the climate sceptics who do not. She asked for a proper dialogue between the two sides, presumably to search out some common ground or a way of respecting each other’s positions,.
As someone who is lobbied strenuously by all sides, I remind the EU and governments that climate change scepticism is not a single doctrine or united group of dissenters against current policy. It is not traditional right or left, and may be motivated by many different considerations. So let us today consider some of the different forms of scepticism there is over this issue.
The first thing to grasp is most climate sceptics do not deny the underlying science which rightly asserts that CO2 is a greenhouse gas. Nor do most deny that if nothing else changes and mankind pumps out a lot of extra CO2 average temperatures will rise.
Some sceptics however argue that current climate models do not capture the complexities of greenhouse gases. Natural CO2 exceeds manmade and that could vary in either direction. Volcanic activity can have a big impact on world climate. A view needs to be taken on the stability of various carbon sinks, including the oceans. Water vapour is a more common greenhouse gas than CO2 so models need to capture variations in water vapour concentrations. That also gets the forecaster into wind directions and cloud formation, which we see have daily big impacts on the weather and over time can affect the climate , if new trends and patterns emerge. These sceptics either say you cannot gauge temperature direction from simply measuring manmade CO2 or go further and argue other trends may be or are offsetting manmade CO2.
Some sceptics point out that the sun is the main source of warming the earth, and that there needs to be more information about solar activity rates, as the sun itself produces variable output over time as well as from night and day and the seasons.
Some sceptics are unconvinced that there has been a linear increase in average temperatures during the long period of industrialising since say 1820. They raise issues about historical records, and about how you actually calculate an average world temperature, as well as pointing to periods in the published records when temperatures did not rise.
Other sceptics accept the predictions that manmade CO2 will take temperatures higher whatever the other forces do. They ask whether it is not wiser and cheaper to spend money on adaptations where warming has adverse consequences rather than trying to wean China and the USA off fossil fuels in time to meet the needs of carbon reduction to head off the problem.
So I say to Mrs Merkel she needs to engage her experts and the EU in a new dialogue which examines these various strands of sceptic thinking and deals with them sensibly, rather than castigating anyone who asks questions. A lot of people are in the middle on this issue, seeking better information and guidance on the nature and scale of the threat. They are more likely to be persuaded by well informed people with knowledge and balance than by angry politicians asserting you either accept their version or are some kind of denier of the truth.