Making sense of emissions

Every year, our local airport, Staverton, publishes its green policy - http://www.gloucestershireairport.co.uk/AboutUs/Environmental.aspx and the latest review is here

http://vmcommin/documents/g2090/Public%20reports%20pack%2010th-Dec-2013%2018.00%20Cabinet.pdf?T=10

We noticed in a report in the Gloucestershire Echo that there was consideration of ‘recalibrating’ the cap on emissions from Staverton. It’s worth noting that the emissions cap is pretty much a voluntary arrangement, and that they are free and able to move the goalposts should the airport so desire.

Curious as to what was going on, and wondering if we needed to take action on this, I started poking round. I read the green policy, and then went on to look at how emissions are assessed.  Defra methodology can be read about here - https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/224437/pb13988-emission-factor-methodology-130719.pdf

Calculating emissions is not an exact science. What this means is that the method we use at any given time to calculate said emissions is a best guess, so we cannot be totally confident that what we think we are putting out has been accurately gauged in the first place. There is also an element of averaging involved – it is not a precise measure. The methods of calculation are being fine-tuned all the time.

I made contact with the council in Cheltenham, to try and find out a bit more about what’s going on here. What I learned is this: There was no formal method for calculating CO2 available when the airport’s green policy was first developed, so a method was devised by an independent consultant. The methodology is shown in the green policy and if you’re curious, do go and have a read. It’s quite manageable for the non-expert (eg, me!). National guidance has since been issued that adds consideration for planes flying at high altitude. I was told the effect of this would be that if 100 tonnes of CO2 was previously reported, this would now be reported as 190 tonnes under the new system. Not all planes from Staverton fly at the relevant altitudes, so there are more calculations to do before any decisions are made.

The airport has operated within the 4.000 tonne CO2 target it’s been set. In 2012/13 it showed a 16.6% reduction on the previous year due mostly to another small change in the national guidance. Some of the improvement can be attributed to more efficient aircraft. That impression of an improvement may be misleading though, given the direction new guidelines have taken.

The new method of calculating emissions means that the same activity will result in a much higher figure in the future. It is my understanding that the emissions ceiling may be recalibrated in response to this. Or to put it another way, having worked out that flying creates more CO2 than previously thought, the response is not to reduce the number of flights out of Staverton or to insist on more efficient planes, but to just move the goalposts so that ‘business as usual’ continues.

I’m not sure what the point is of trying to ascertain our actual emissions, if the response will be just to change the rules so that what we were doing continues unaffected.