Travelling Within Budget

Travelling within budget, for so many years, has been about cost; typically, the financial cost to an individual or company. But the definition of cost is much broader than financial and now, in this critical decade for our environment, we must ensure that the cost of any activity on our planet is at the heart of our decision making.

Budgets are increasingly focussing on carbon budgets and aligning to Science Based Targets and data, but for the purpose of this story, I will be talking about my Sustainable Aviation Fuel (SAF) budget and reducing the environmental impact of air travel, while also sharing the overall journey I have been on for the past 15 years.

It brings me up to date and describes the action I am now taking to reduce my own emissions – and explains why I see the direct purchase of SAF as the way forward (for the next few years at least before SAF increases in scale and is included in airfares or taxes).

I am of course also aiming to be more selective about the amount of travel I do and will be aiming to cut my overall travel by 50% (compared to when I would previously have made a trip). However, for me, ‘Travelling Within Budget’ is about feeling able to travel when I want to – or need to – and taking tangible action to make that possible. Here is my story and why I believe that a direct purchase of SAF is the current best answer for anyone who needs to travel by air.


An Inconvenient Truth is a 2006 American documentary film directed by Davis Guggenheim about former United States Vice President Al Gore’s campaign to educate people about global warming. The film features a slide show that, by Gore’s own estimate, he has presented over 1,000 times to audiences worldwide. It remains a super-simple explanation of climate change.

I must confess, I cannot recall whether it was this film specifically, or just increased media coverage about global warming at the time, but I was drawn to the argument that climate change was something we could influence – if the amount of Carbon that people put into the atmosphere could be reduced. And, coming from the travel industry as I do, I felt an increased responsibility having benefitted directly from the number of passenger aircraft flying – burning jet fuel and leaving contrails of additional cloud and CO2 in the sky.

And so it was, during 2006, that I began reading more about travel-related carbon and gathering articles and presentations for my own use. I thought I could/should share this information more openly and in September 2006, registered the domain and started up a website (a simple portal) which contained a growing list of links to reports and presentations which covered the environmental impact of business travel. It was a free to use and open to anyone who may be interested.

The site generated a respectable number of visits, (for this read hundreds, not thousands!) and was sufficient for me to remain motivated to continue to add content – helping in a small way to share information with an audience who found it useful. Of course, none of us could have known what was around the corner, or the chaos that was about to happen.

The global financial crisis (2007-2008) had a deep impact on many things, not least the collapse of interest in sustainability. By 2009 interest in the environmental impact of business travel had more-or-less evaporated and certainly disappeared off the boardroom agenda. Very few people were bothered about climate change while their companies focused on financial survival and recovery… It stayed this way for another 10 years!

And my own interest in travel-related carbon during this time became less. It was always in the background, but with so few people wishing to engage – and my travelcarbon website receiving virtually no visits, it seemed pointless maintaining something with no audience. I turned the site off and focused on other things.


It was not until August 2018 that things started to change. Sight of 15-year-old Greta Thunberg outside the Swedish Parliament and the School Strike movement combined with other global protests, gained significant media interest and with this came corporate attention.

Prior to 2018, if you had attempted to hold a workshop or event about business travel sustainability you may have been lucky to attract a handful of people. Then suddenly, it all changed. 30, 40 50…one hundred people were turning up to talk about the environmental impact of travel programmes. Carbon calculators, offsets and environmental projects took off as companies looked for ways to claim their programme was ‘carbon neutral’ – or that their corporate emissions had been ‘offset’…Green badging and the ‘problem’ would be solved?

Carbon Calculators And Offsetting

In late 2019, I was looking into the cost of offsetting a trip and realised there were no common standards – either for the carbon calculation, or the cost/value of the offset. It took me a while to work out that much of the market was a complete ‘free for all’ with little transparency and not much regulation. And that even some of the firms who were claiming to set the standards were themselves focused on their own interests.

I accept this is a very sweeping view and that there are very many genuine organizations and committed people doing excellent work around offset projects but weeding through it all to find the right answer is complicated, uncertain, and almost impossible. Here is the reason I am so sceptical about carbon calculators and offsetting:

Between November 2019 and January 2020, I looked at over thirty different carbon calculators – each claiming to report the CO2 for an LHR/JFK/LHR return trip. The range of different results was unbelievable.

The amount of CO2 for the trip was said to be between 0.66 tonne and 10.58 tonnes!

Some calculators quote CO2 only, others add more to cover all greenhouse gases, others add ‘radiative forcing’ (the impact of fuel burned at high altitude), some show different amounts for economy, business and first class. They are all different.

This CO2 figure is important, because the amount of CO2 is then multiplied by the ‘project’ price. And, with so many different projects, all at different prices, the cost of buying an offset on just one city pair will show hundreds of different amounts.

Of course, each calculator and offset company claims to be right. The term ‘high quality’ is often used to suggest a project is somehow better than others, but even those organisations who certify projects can be questionable – especially if their fees for certifying projects are paid for with credits which they then sell through their carbon calculator to raise cash for themselves.

Disillusioned from this experience, I needed to find a better answer, or rather a better alternative to offsetting. I needed more ‘line-of-sight’ and assurance that emission figures are genuine and the amount you are being asked to pay is both accurate and will deliver a direct reduction in CO2…. My search took me to Sustainable Aviation Fuel.

I am not claiming to have found a magic answer, or that my interest in Sustainable Aviation Fuel is the only long-term solution – but aside from not travelling or using an alternative means of transport, SAF is recognised as the most effective way of reducing air travel emissions today and is the most direct action you can take if you wish to reduce the impact of your travel.

The main challenges are:

1. SAF is expensive (x3 to x5 the price of regular jet fuel) and

2. There is VERY little current production

However, SAF is available today. It is possible to purchase an amount fuel and place it with an airline or your choice (if they will accept it).

The fact that SAF is available, is the crying shame – because with only 300,000 tonnes of SAF produced globally – compared with the 300 million tonnes of fossil jet fuel consumed annually (SAF = 0.1%) – there really should not be any SAF available anywhere – but there is. (Hold that thought for a moment.)

Finally, neat SAF is a ‘drop in’ fuel that is blended with fossil jet fuel in ratios of up to 50:50*. It requires no modification to the aircraft or its engines and can be used on practically any passenger jet aircraft. (*Trials are currently underway to allow aircraft to fly on 100% SAF with test flights reporting very positive results.)

The CO2 reduction from SAF is claimed through the life cycle of the materials used in its production (biomass, waste cooking oils, waste animal fats etc…). It took me 3 months to work out that jet engines burning SAF produce the same amount of CO2 as regular jet fuel – however, the CO2 from burning SAF is recirculating short term carbon from plants and other materials – rather than unlocking fossil Carbon that is millions of years old (and will otherwise cause additional CO2 into the atmosphere).

The emission reduction achieved from SAF is therefore claimed to be approximately 80% compared with fossil jet fuel. It is especially important to recognise that this claim is for the neat SAF – it is only ‘neat’ SAF that delivers the full 80% emission reductions.

The maximum blend allowed today is 50:50. This means that one hundred litres of blended fuel contains 50 litres of fossil jet fuel and 50 litres of SAF. If the one hundred litres of blended fuel is described or promoted as ‘SAF’ then only fifty litres of that blended fuel is neat SAF. The one hundred litres of blended fuel has a total emission reduction of 40%.

We are starting to see offsetting companies, carbon agencies, and other SAF promoters offering CO2 reductions by selling SAF % – for example buy 10% SAF with 90% offsets to make your flight ‘carbon neutral’. While any promotion of SAF is good, there is risk of SAF being prone to the same issue of offsetting and uncertainty surrounding precisely what you have purchased. There is also a risk of double-counting reductions, especially if it is not clear how the actual fuel is obtained, blended, supplied, and used.

The way around all this is to establish direct line-of-sight to the producer and then be able to audit trail the neat SAF through blending, supply, delivery, and placement with the airline of your choice – with assurance that it is your SAF and exclusively yours to claim the emission reduction, with no risk of double counting.

What exactly have I done with my SAF budget?

I have committed to the purchase of one tonne/1200 litres of neat SAF directly from the producer, which I am managing in a ‘proof of concept’ budget. The key difference between this budget and any other SAF scheme is that I am focused on the fuel and not the CO2.

I have no interest in using a CO2 calculator to determine how much SAF is required. I am aiming to establish the amount of regular jet fuel used (per seat) for any flight that I take.

For example, if a return trip from London to Madrid on BA (per seat) costs one hundred litres of Fossil Jet fuel, then I know to deduct one hundred litres of SAF from my account. Eventually when all of my trips reach a total of 1200 litres, I place the one tonne of fuel within a batch to my chosen airline (probably British Airways) and start again with another one tonne. My only dilemma is whether to match fossil jet fuel with neat SAF 1:1 and reduce my emissions by 80% or increase the SAF ratio to 1:1.2 and reduce emissions by a full 100%?

So, the journey continues…

Written by John Harvey – Managing Partner at H&H , Founder at Globalyse.

Please feel able to message me or ask any questions at or My only disclaimer is that I am not an environmental expert or Sustainable Aviation Fuel specialist. I would always encourage you to do your own research.

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