Market measures are the quickest and most effective way to reduce aviation CO2 emissions, find climate researchers

Market measures are the quickest and most effective way to reduce aviation CO2 emissions, find climate researchers | MMU,CATE,David Lee,ICAO 38th Assembly

Fri 30 Aug 2013 – Although a mix of strategies is required to deal with the climate impact from the rapid growth of carbon emissions from aviation, the fastest and most effective method is through market-based measures (MBMs), concludes a report by climate researchers from Manchester Metropolitan University’s (MMU) Centre for Aviation, Transport and the Environment (CATE). Delaying the implementation of MBMs and setting carbon reduction targets for future dates fail to factor in the physics of CO2, they say, namely the accumulative nature of CO2, its long lifetime in the atmosphere and its consequent effect on climate. The report – ‘Mitigating future aviation CO2 emissions – timing is everything’ – has been released ahead of an important meeting of the ICAO Council next week (September 4) that will deliberate the contents of the climate change resolution to be put to the ICAO Assembly later in the month.


The CATE researchers – Dr Ling Lim, Dr Bethan Owen and Professor David Lee – conducted over 11,000 complex calculations in their analysis of a range of aviation mitigation options and quantified their relative benefits in terms of their impact on climate. The mitigation measures considered included technological and operational improvements, the introduction of biofuels, an actual MBM (the EU ETS) and a hypothetical global MBM and compared them with a business-as-usual technology and operational improvements scenario.


Prof Lee and his colleagues demonstrate that MBMs such as emissions trading achieve immediate reductions and are therefore the fastest way of lowering emissions and a more effective means of reducing climate impacts.


A global MBM based on international departing flights introduced immediately, along with the other mitigation measures, could reduce the climate impact – measured using the radiative forcing (RF) metric – from aviation by 30.1% by 2050, they say (see Figure 1 below). By comparison, RF savings from business-as-usual improvements in technology, operational measures and biofuels amount only to 1.1%. If technology and operational improvements and biofuel take-up are greater than expected in the period to 2050 – termed maximum feasible reductions (MFR) – the RF savings increase to 9.0% if only these mitigation options are employed, but rise to 30.4% if a global ETS is adopted as well (see Figure 2 below).


While emissions trading as a measure was found to offer the single largest incremental improvement in climate impact by 2050, the least effective was biofuels, even using the assumptions of the UK Committee on Climate Change’s “speculative levels” assessment of potential biofuel availability in 2050. Maximum feasible reductions from improvements in technology and operational improvements offered the second best mitigation potential as a single measure.


“The problem with conventional technology development and fleet uptake of improved technology for reducing emissions is that it takes time, and time is what we don’t have if we are to avoid exceeding an increase of 2⁰C by 2100 over pre-industrial temperatures,” said Prof Lee, who is also Director of CATE and leads a team that has provided advice on aviation and shipping climate-related issues to the UK government, ICAO, UNEP, IMO and the European Commission.


“The sector needs to pursue innovation, but also needs to be flexible in its approach and appreciate that early reductions in CO2 also need to be pursued vigorously.


“What we show is that MBMs – such as the EU ETS for aviation, the subject of so much political controversy and currently halted [on intercontinental flights] while ICAO tries to broker an international agreement – are the most effective solution, other than a full-blown international aviation MBM such as emissions trading for aviation CO2 emissions.


“While political negotiations take time, and development, the problem is that day by day we lose opportunities to reduce CO2 emissions.”


The report was welcomed by environmental NGOs, which are concerned that ICAO member states will further delay a decision on whether to adopt a global MBM.


“This robust analysis is compelling and should be a wake-up call to states and industry as they prepare for ICAO’s Assembly,” said Bill Hemmings of T&E. “ICAO’s traditional approach focusing on technology, operations and biofuels falls far short of what is needed.”


Tim Johnson of the Aviation Environment Federation (AEF) commented: “ICAO has already demonstrated that its own modest goal of carbon-neutral growth by 2020 will be impossible to achieve without market-based measures, while the scale of reductions required to contribute to a 2 degree pathway reinforces that argument unequivocally. It’s time to stop debating the ‘if’ and focus on the ‘how’.”


The MMU CATE ‘Timing is everything’ findings follow up a similar report, ‘Bridging the aviation CO2 gap’, it published in March 2013 (see article).


Figure 1: CO2 radiative forcing savings for international aviation from business-as-usual (BAU) technology and operations improvements in combination with different mitigation options, compared with the BAU scenario (source: MMU CATE):



Figure 2:  CO2 radiative forcing savings for international aviation from maximum feasible reductions (MFR) from technology and operations improvements in combination with different mitigation options, compared with the BAU scenario (source: MMU CATE):






MMU CATE report

T&E/AEF statement on the report



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