Should we tempt readers to travel by air when the planet needs saving? We have had some spiky debates on the issue .Those of us who believe passionately that we should have been given a lift by the Committee on Climate Change, which has concluded that, for the time being at least, we can carry on flying. It suggested passenger travel from the UK could rise 60% without crippling the Government's aim of keeping aviation CO2 in 2050 no higher than than in 2005.

That percentage could be optimistic – or pessimistic. The Committee's report cited many uncertainties - over likely traffic growth, for example and the extent to which biofuels can replace aviation kerosene. It is not even known how much damage is caused by aviation emissions other than carbon dioxide.

Uncertainty is healthy. We know global warming is happening. What is less is less clear is how to tackle it effectively within the bounds of the achievable. Uncertainty strengthens reasoned argument against the shrill demands of zealots. Is high speed rail in Europe really such a no brainer, for example. The report suggests it might divert only 8% of air passengers: a very small environmental return on investment.

I have always believed air travel produces more positives than negatives in the arena of international understanding. That makes it too precious to be thrown away without compelling reason. Ways must be found to make aviation greener but its effect on climate change, compared with the big industrial CO2 emitters, is modest. The idea that individuals should make the gesture of giving up flying strikes me as ludicrous.

If nothing else this report provides ammunition against those fundamentalists who believe we should stop all non essential flying – and that suggesting readers go by train instead is something of a futile gesture.