2020 Vision Exeter
Reducing Exeter’s carbon footprint by about 80% by 2020
|
|---|
1: Target 2: Vision 3: Descent 4: CRAGs 5: Ethic 6: Process
1: Setting an ambitious targetWe have established two targets that are more challenging than the ones set by government.There is a good reason for this; the government’s targets are weak and dangerous. The reason is that the government’s target of 80% reduction by 2050 is predicated on a 50% probability of keeping global temperatures below 2° C above pre-industrial levels. No one would fly in an aeroplane if there was only a 50% chance it wouldn’t crash, and yet we appear to be quite happy to take that level of risk with our climate. We have used research by M Meinshausen et al. published in Nature 458 (March 2009) to calculate the emissions permitted under different probabilities of success.. This research correlated the total volume of CO2 emissions over the first half of the 21st century against the probability of keeping global temperatures below 2° C. It establishes that for a 50% chance then only 1,440 gigatonnes of CO2 can be emitted between 2000 and 2050. This has led to the assumption of 50% global emissions cuts by 2050, and 80% cuts by industrial nations. 
But should we not try for better odds than 50:50? We used the PRIMAP model (Potsdam Real-time Integrated Model for probabilistic Assessment of emissions Paths) to establish emissions with improved probabilities. See http://www.primap.org/ If we choose a 70% probability of keeping below 2° C, then global emissions should be less; 1100 gigatonnes. On a pro-rata population basis this is equivalent to approximately 10 gigatonnes for the UK. In the first 10 years of this century emissions from the UK amount to 5.4 gigatonnes, so it if fairly clear that carbon emission cuts from 2010 need to be quick and deep. The carbon descent graph for Exeter would follow a similar curve to that for the UK as a whole. The percentage reductions relate back to 1990 baseline emissions. We have developed the following graph that fits reasonably well with a 70% probability of keeping below 2° C. 
The figures for CO2 emissions are from the government’s published statistics for Local Authorities: See http://www.decc.gov.uk/en/content/cms/statistics/climate_change/data/data.aspx In 2007 (the last figure released) CO2 emissions from Exeter were 673,000 tonnes. This is less than the national average for 3 reasons, Exeter has warmer weather therefore heating bills are less, it is a city which has more efficient travel patterns, and also Exeter has very little industry. There are no published figures for Exeter’s CO2 emissions in 1990 (the baseline figure for reductions calculations). But Exeter University Centre for Energy and the Environment has estimated what they would be in their report: “Exeter Climate Change Strategy Analysis” (Jan 2008). They calculated 736,000 tonnes. Thus CO2 emissions figures available are as follows: 
The government also produces a series of indicators (referred to as N186) to identify how the Local Authority is performing against its indicator target. These figures are also shown above. However there is one important aspect missing from the above figures; air travel. The following table includes the impact of air travel emissions on Exeter’s total CO2 emissions: 
(*) Based on a pro rata population figures for Exeter and the UK. Uses UK Domestic and International air travel CO2 emissions and assumes a 2.7 Radiative Forcing Index multiplier. Since air travel emissions in Exeter are calculated to be over 20% of total emissions they should not be ignored, and must be taken into consideration when developing a low carbon vision. |
Latest Update ... April 2010 |
Any updates, modifications, please contact Maurice
|
|
