Offsetting Clear Sky’s Climate Impact

by Robert Boyle, Partner at Clear Sky

As an investment company dedicated to accelerating aviation’s journey to net zero, it goes without saying that it’s important for us to offset our own air travel emissions and to do so in a comprehensive and transparent way.

Nowadays, many airlines offer the option to purchase carbon offsets when booking a flight. While it is convenient to check a box during checkout, this method may not be the most effective way to mitigate climate impact. Firstly, there are significant discrepancies in how emissions are calculated across different airlines. On top of that, the methods each airline uses to manage and allocate their offset funds vary greatly and are likely to lead to diverse and inconsistent outcomes.

On the other hand, if you decide to go it alone with your offsetting, there is a veritable buffet of initiatives to choose from. These include planting trees, investing in carbon capture, contributing to renewable energy projects, purchasing carbon credits from a third party, right through to using whale excrement to promote phytoplankton[1].

With so many options, what is the right thing to do? In deciding on our approach, we reviewed the options for calculating the climate impact of the flights we take and the available mechanisms for offsetting that. Whilst our approach will continue to evolve as more accurate methodologies are developed by the industry and the market for carbon offsets matures, we wanted to set out our current policy and the thinking behind it.

The first step of an effective offsetting policy is to establish the emissions. There is a plethora of online services which claim to calculate flight emissions, but many are very simplistic, using high level averages. That is a problem, as there are huge differences in emissions depending on the class of travel, the fuel efficiency of the aircraft employed and the specific characteristics of the route in question, amongst other factors.

We quickly narrowed down to what we felt were the two most credible options: Google’s Travel Impact Model andIATA’s CO2Connect service. Both make allowance for the aircraft type operated, the cabin of travel, and the specifics of the route. Google is more sophisticated in the way in which it attempts to allow for the actual seating density and typical load factor of the flight, which can of course vary by airline. However, IATA’s methodology for estimating fuel burn based on flight duration is superior to Google’s purely distance-based formula, better reflecting the impact of winds and real-world routings. We also felt that IATA were more properly addressing the split of emissions between passenger and cargo and had the advantage of access to real-world fuel burn data from their member airlines to calibrate their model.

We have therefore decided to use the IATA model as the basis for calculating the basic carbon emissions from burning jet kerosene on the aircraft, also known as the “tank to wake”, or TTW emissions. Google include a 20% uplift for the upstream emissions of fuel suppliers (“well to tank” or WTT), that is the emissions caused by the extraction, refining and transportation of the fuel. IATA’s calculator does not include those, as they are not direct emissions of the airline industry. However, we think these should be included for our purposes of offsetting our overall climate impact and therefore uplift the IATA numbers by 20%.

There are many companies and services offering carbon offsets. The cheapest of those come in at around $15 per tonne of CO2.Those typically offset carbon emissions by avoiding deforestation, planting trees, or investing in projects outside of aviation which deliver carbon reductions, often in the developing world.

Whilst many of these projects undoubtedly achieve genuine reductions and foster more sustainable development around the world, we want our offset money to help drive the two main contributors of aviation’s pathway to net zero, namely Sustainable Aviation Fuel (SAF) and carbon removals, which directly takes CO2 from the atmosphere.Today, the cost of carbon reductions in both those areas is substantially higher, typically costing $200-300 per tonne of CO2 saved. Despite the additional cost, we feel that SAF and carbon removal credits better reflect our mission to accelerate aviation’s journey to net zero.

We will therefore be purchasing such high quality carbon removal credits, and will do so through third-party partnerships - full details of these will be announced shortly. In addition to this, over time we also intend to allocate offset funds to SAF projects where we can be confident of verifiable carbon reductions on a lifecycle basis and where credits meet stringent additionality tests.

This has been our journey in carbon offsetting so far. We hope you find our thoughts and approach interesting and helpful if you are looking to mitigate your own climate impact. The landscape of carbon offsetting is continuously evolving, and we are committed to adapting and refining our strategies as new methodologies and more accurate data become available. We will continue to share updates on our progress and insights as we all navigate a path towards a more sustainable future for aviation.

[1] https://www.reuters.com/article/idUSTRE65F0HA/