INTRODUCTION
Sustainable aviation: The journey to net zero
The future of flight will look very different from today, and hopefully much more sustainable. For planes, kerosene will eventually give way to other propulsion sources, whether electric, hydrogen fuel cells, or sustainably produced fuels. Meanwhile, the nature of flight itself will be transformed, as new airborne transport modes, such as air taxis - which will have sustainability designed in from the start - pass certification and hit the market.This will all have far-reaching effects. New propulsion mechanisms may open up more efficient plane designs, which may radically alter the 100-year-old aviation template. Innovations in materials science and recycling may also be revolutionary for aircraft designs. On both new and old designs, new sensors and data will incrementally optimize everything - from airflow over the wings to flight routes - in order to squeeze further energy efficiency gains. All of this will have an unprecedented impact on global supply chains for fuel, materials and manufacturing.
This cannot happen soon enough. Aviation is responsible for at least 2% of global carbon dioxide emissions according to the International Energy Agency (IEA), though the release of these emissions at high altitudes (eg. nitrogen oxides that increase ozone formation, and water vapour that traps heat through contrail formation) means they have an outsized effect on global warming.
Addressing this in every sector is increasingly urgent. The global average temperature has already risen by about 1.1C above pre-industrial levels, according to the Intergovernmental Panel on Climate Change (IPCC), approaching the limit of 1.5C, which the Paris Agreement hopes to keep to.Aviation has committed to being part of the solution, and the global aviation industry has agreed to net-zero emissions by 2050.
The big impact will come from sustainable fuels – with a variety of approaches being explored. For example, Airbus aims to field a zero-emission aircraft by 2035, and is investigating hydrogen combustion and fuel cells. Boeing, Airbus and others are exploring sustainable aviation fuels (SAFs). Various start-ups are exploring fully electric and hydrogen-powered aircraft - and have recently demonstrated that success is possible.
However, other changes are also needed to reduce emissions and energy required – from aerodynamic designs and lighter materials, to more efficient computer-aided flights and route planning. Supply must also change, replacing dirty raw materials and polluting factories with clean biomaterials, recycling (the ‘circular economy’), and suppliers running on renewable energy.Yet, all of this must happen in a period of aerospace growth, fuelled by new demand (especially in Asia), and increased fleet sizes.
But, to meet a carbon budget compatible with the Paris Agreement, this increase in air traffic volume must be balanced with emissions reductions - and will likely be part of a growing debate in the near future, with airlines, airports, consumers and governments all exerting pressure.
Sustainable aviation is a complex challenge that must be tackled in various ways. We are now at a key moment in aviation history. We require a massive, coordinated effort, and a reanimation of the passion of aviation pioneers. We must reignite this spirit of innovation, driven by a sense of urgency, because failure is not an option, and the clock is ticking. Below, we cover how this must be done.So, how do we make aviation part of the solution?In each piece in this series, we will cover various ways to decarbonize aviation.
