Aviation long-term decarbonisation workshop

January 30, 2018

T&E convened a workshop to discuss emissions reduction pathways and measures for aviation in light of the Paris requirement for all sectors to cut emissions and to decarbonise by the second half of this century.


The meeting convened scientists with policymakers, industry and NGOs to discuss the current trajectory of aviation emissions given existing regulatory and industry approaches. It examined what additional measures – technology, fuels, operations – could be deployed before 2050 and the policy measures that would be needed to do so.

Dr John Broderick from Manchester University, Tyndall Centre, opened with an overview of the carbon budget available in order to meet the Paris agreement goal of 1.5C and well below 2C. According to the proportional share of the carbon budget and in order to have a 50% chance of meeting the 1.5C temperature goal, the aviation sector will need to reduce CO2 emissions intensity (gCO2/RPK) by 13.8% annually from 2016 towards zero.

Ir. Joris Melchert from TU Delft reviewed new aircraft designs and technology innovations that could be deployed by and before 2050 to reduce emissions. His assessment included the physical constraints, new wing and aircraft designs, hybrid-electric and hydrogen etc. The overall conclusion given the challenges of physics; there are no quick fixes, more R&D is needed and growth needs to be tackled.

Dr Harry Lehmann, German Environment Agency, made the case for developing power-to-liquid drop-in fuels for aviation. They were technology ready, ways were needed to start small-scale deployment and then bridge the price gap with kerosene. Dr Chris Malins, from consultancy Cerulogy, outlined the potential sustainable alternative fuels that could be delivered by 2050 along with the potential emissions reductions and costs compared to conventional fuels along with the constraints to deployment. Also discussed were some of the potential policies that would be needed to support the uptake of these fuels within the aviation sector.

The scale and climate impact of non-CO2 effects from aviation was presented by Professor Dr Volker Grewe from DLR and TU Delft. Non-CO2 climate impacts – radiative forcing from  NOx emitted at cruise, contrail/cloud formation and soot – are larger than CO2 yet they remain unregulated. Combined they mean that the aviation sector alone contributes around 5% to global warming. Policy measures such as optimised routings avoid contrail formation were outlined, the need for more research on aircraft avoiding sensitive climate areas emphasised, as was the fact that offsetting CO2 has no impact on reducing non-CO2 effects.

The closing panel debate on policy measures sought to draw some conclusions on next steps.The workshop widened the debate on options for addressing aviation’s climate impact. At the same time the enormous challenge to align aviation with the Paris Agreement goals is clear. T&E will be following up the workshop with more focussed sessions on particular aspects raised during the day.

Please find the presentations here below: