Aviation

Back in December a report entitled Meeting the UK aviation target – options for reducing emissions to 2050 was published by the Committee on Climate Change (CCC) to suggest that UK demand for flights could increase by 60% by 2050 and stay within the Government's emissions target of no increase above 2005 level.

This is at odds with what I have been saying about the need to reduce rather than increase flying. How come I seem to be at odds with the CCC?

Firstly, the report was commissioned to report on the feasibility of containing aviation emissions in 2050 to 2005 levels. The thinking is that if the target of total UK emissions cuts of 80% is to be met, no cuts in aviation emissions are required if non-aviation emissions are cut by a correspondingly larger amount - say by 85%. I don't find this argument very persuasive. Suppose that by 2040 we have achieved an 80% reduction in non-aviation emissions. By then we will have found all the easy ways to cut emissions. What will remain will be the most difficult. Between 2040 and 2050 we will have to cut emissions by 25%.

To my knowledge, there is no official strategy for how the UK will achieve the emissions cuts beyond what we achieve by 2020. My gut feeling is that getting non-aviation emissions down beyond 80% will involve some fairly serious sacrifices in living standards and I wonder what sort of sacrifices people will be willing to make in order to be able to fly thousands of miles for their holidays. In any case, my 85% figure may be conservative. It is predicated on a 6% figure as international aviation's share of UK emissions. However, the 6% figure is for departures from UK airports, not for UK residents departing and arriving. Because more UK residents than foreigners fly to and from British airports, UK residents' emissions from international aviation would be higher - the CCC estimates 7-8%.

Secondly, the target for containing emissions is for 2050. Hitting our 2050 targets is important but more important is the the quantity of greenhouse gases we emit between now and 2050. The sooner we can reduce our emissions, the better chance we stand of avoiding catastrophic climate change. It will take time to decarbonise the basics of life - keeping ourselves fed, warm and clean and travelling to work. By contrast, cutting down on flying is something we can do immediately. Most flying is discretionary in the sense that we don't need to do it in order to carry on our normal daily lives. We can take holidays in Europe rather than in Florida or Thailand and we can travel by train to most places in Europe. Flights obviously vary in importance to the flyer but I have a strong feeling that a great deal of flying could be eliminated for a very small sacrifice in human happiness. The existence of a government target for 2050 that can be met with some increase in flying does not, in my view, relieve us of the moral obligation to sieze what opportunities we can to reduce our flying and hence reduce the risk of climate catastrophe.

Thirdly, the CCC left out any factor for the increased global warming potential of greenhouse gases emitted at high altitude. Its terms of reference were to report on the feasibility of the emissions target itself, not on its global warming effect. However, the report flags up a need to take into account the full effect of aviation on global warming in future targets. This suggests that the overall message from the report would have been very different if the terms of reference had referred to the total global warming effect rather than simply the emissions. In 2005, international aviation might have accounted for between 12% and 16% of the UK's total impact on global warming.

Overall, this report doesn't change anything for me. A cursory glance at the report may suggest that it's OK for us in the UK to increase our flying by 60% but that's not how I see it. Cutting down on flying is an opportunity to reduce the risk of future catastrophe and we have a moral obligation to seize it.

NOTES FOR NERDS

For simplicity's sake, I ignored the fact that the target for UK emissions reductions is from the 1990 figure, not 2005. On the basis of Kyoto methodology, which excludes international aviation, the UK had already achieved a 16% reduction by 2005. The relevant figures are as follows:-

Total UK greenhouse gas emissions, million tonnes CO2 equivalent:
1990: 773.0
2005: 652.8

Source: http://www.decc.gov.uk/media/viewfile.ashx?filepath=statistics/climate_change/1_20091008144835_e_@@_ghgns200090326.pdf&filetype=4 downloaded 13.1.2010. Click on "Annex A" on page 1 to download the relevant statistics as a spreadsheet.

These figures are as defined for the purposes of the Kyoto Protocol and include emissions from domestic but not from international aviation. According to the Government:-

"In 2005 aviation represented 6.3 per cent. of UK emissions, calculated as a proportion of emissions in the UK inventory plus emissions from international aviation and shipping departing the UK....

"As the 'Future of Air Transport Progress Report' (December 2006) noted, aviation emissions arising from the combustion of kerosene include carbon dioxide, water vapour, nitric oxide and nitrogen dioxide, particulates and other compounds. These give rise to “radiative forcing” impacts. The total radiative impacts were estimated by the EC TRADEOFF project to be approximately twice those of carbon dioxide (excluding cirrus cloud formation).

"Using a radiative forcing multiplier of two, emissions from flights departing the UK contributed approximately 13 per cent. of total UK emissions in 2005. However, the figures for non-aviation sources do not include any radiative forcing attributable to them, as conclusive figures are not available."

Source: http://www.publications.parliament.uk/pa/cm200607/cmhansrd/cm070502/text/70502w0005.htm

According to the CCC report (Box 1.3 p39), domestic aviation accounts for about 0.3% of UK emissions - hence the figure I have used of 6%, which 6.3% for total aviation quoted in the Parliamentary answer above, less 0.3% for domestic avaiation in the CCC report.

Unfortunately I have so far been unable to find a suitable figure for aviation emissions in 1990. Without that figure it is difficult to provide more than a highly simplified analysis. It is common knowledge that UK aviation has grown substantially since 1990 and hence, once we have taken aviation into account, total reductions in ghg emissions between 1990 and 2005 will be less than the 16% I have quoted above.

Also, the Kyoto methodology ascribes emissions according to where they are produced. It is common knowledge that between 1990 and 2005, a great deal of UK manufacturing production was, in effect, "outsourced" to developing countries, particularly China. Hence if we calculated emissions on the basis of consumption by UK residents, we might see no reduction at all, and possibly an increase, between 1990 and 2005.

A similar consideration applies to international aviation. Flights originating in the UK can be considered part of UK "production". Flights by UK residents can be considered "consumption". The report suggests a figure of 7-8% (Box 1.3 p39) as a figure for emissions from flights by UK residents.

Perhaps it is now obvious why I have had to confine myself to simplified, indicative figures.