The latest Intergovernmental Panel on Climate Change (IPCC) report manages, somehow, to ratchet up the sense of urgency surrounding the climate crisis, when you may have felt there were no more gears left. Strikingly, UN Secretary General António Guterres adds the emphasis to the report’s sobering findings and recommendations with a rhetorical haymaker of his own, and invoking an all conquering Oscar winning film in the process:

 

—This report is a clarion call to massively fast-track climate efforts by every country and every sector and on every timeframe. Our world needs climate action on all fronts: everything, everywhere, all at once.

This means two things for the aviation sector: 1/ we need to accelerate the furthest-reaching solutions that tackle the full climate impact of aviation (i.e. novel, zero-emission propulsion technology) and 2/ as other sectors respond to this clarion call with renewed vigour, hard to abate sectors will stand out more clearly.

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Aviation, too, needs everything, everywhere, all at once. The industry needs increased volumes of biofuel SAF in whatever quantities are possible without impacting food resources or biodiversity. As the only game in town for certified, commercial aviation currently, we need to scale up the production volumes aggressively across the world.

We also need to advance the use of hydrogen, which will make even deeper cuts into aviation’s climate impact and enable the sector to tap into the plentiful renewable energy resources that are available and waiting to be accessed.

But we also need to recognize that flying on combustion engines, even if carbon neutral (SAF) or zero-carbon (hydrogen combustion), is unlikely to be considered particularly green in the coming decades, especially if volumes remain challenging. Even with abundant supply of SAF, growing understanding of non-carbon emission impact will soon erode any grace afforded to the industry for reducing its carbon emissions.

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The hydrogen-electric propulsion technology we are developing at pace will offer the long-term solution for all aircraft size categories ultimately, and can be technologically viable for aircraft up to the single aisle category by the mid-2030s, thus enabling the industry to tackle more than half of its GHG emissions. It will also tackle air quality impacts at or around airports.

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Too often, the potential for zero-emission aviation is dismissed as too far in the future or constrained by renewable capacity. But these engines are now flying commercial-scale aircraft, and the compelling case presented by Tesla as part of its investor day should give us all optimism for the opportunity to rapidly scale renewable capacity.

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If we are ambitious enough in encouraging and supporting the adoption of zero-emission flight, we can have the technology to tackle the majority of the sector’s greenhouse gas emissions well ahead of 2050, but existing roadmaps rarely reflect that opportunity.

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One thing is clear from the IPCC’s “final warning” - the time for modest interventions is running out. Policies need to be bolder across the board, and aviation, the fastest growing source of greenhouse gas emissions, needs to be included. If SAF and market-based measures are the majority of carbon emissions abatement in 2050, the industry will not have succeeded.