Do cars produce more CO2 than planes?

According to today's Times, the anti-aviation movement has "duped" the public into thinking that planes are more polluting than cars. The National Omnibus Survey shows that 40% of people think planes are the most environmentally damaging form of transport. But are they?

Survey results are like Shroedinger's cats: any statement about them can be simultaneously true and false. Aviation is the most polluting mode of transport for any given journey, but not in terms of total CO2 emissions. Cars produce 69.9 million tonnes of CO2 while domestic and international aviation emitted 37.5 million tonnes.

So have we duped the public? The survey first presented participants with a list of transport modes and asked "which of the following, if any, do you think are major contributors to climate change?" It then asked "which do you think contributes the most" without specifying per journey or in total. A little clarity in the questioning would have been helpful.

But there's much to welcome in the survey. 15% of people plan to fly less in 2008 (up from 13% in 2006). But hilariously for a government that talks of 'green growth' and the need to balance stopping climate change with making cash for big business, comes this question:

"Which of the following statements comes closest to your own views. Is it...
(1) air travel should be limited for the sake of the environment,
(2) or, limiting air travel would be too damaging to the economy?"

Looks like it's ok for the government to be "pro-green, pro-growth" - just not for us civilians. We have to choose... and 47% of people chose to reduce flying. Given such a loaded question, that's not a bad result.