How Evil is Diesel, Or, The Case for Systems Thinking

Our blog this month is written by Cliff Betton, Chairman and CEO of Delphic HSE.

Cliff is a Zoologist by training and throughout his career has worked in a number of roles relating to environmental safety, human health, and safety assessments for a number of different organisations including Unilever, BP, Castrol, and Intertek. In 2005 Cliff began his own company, Dephic HSE Solutions Limited, and has since lectured on risk based safety internationally and published a number of scientific papers on environmental issues.


There was an interesting headline in the news the other day, indicating that CO2 emissions have increased significantly and that it was due to the move away from Diesel fuelled cars as a result of concerns about air pollution.

This of course is true and an inevitable consequence of taking environmental issues individually. It is not possible to control one aspect of the environmental impact of humanity without affecting adversely, something else. The Gaia hypothesis may seem a bit “trendy” – treating the world as if it was alive and a living thing, but it is true nonetheless. One thing affects another and everything is interdependent, push down here, and it goes up over there instead: matter can neither be created nor destroyed, it is merely redistributed.

The problem with any species that increases in numbers without control, is that it eventually destroys the environment that it occupies; all the food is consumed and the waste products mount up, causing all number of adverse effects. Basic environmental science. Wildebeest can migrate to new pastures, soldier ants can up and move en mass through the rainforest. People however, occupying every environmental niche on earth and over water, have moved as far as we can. We have also removed most predators, prompting lists of endangered species and charities that “sponsor a ……”, mostly driven from the countries where all the predators were long ago wiped out. Efforts are made, things are changed, but these are frankly token gestures that make the rich and wealthy feel better: and still the forests are shrinking, just the zoos get bigger but we now call them protected areas.

There are too many of us humans. We consume the environment, either as living space and thence directly as food – food for us, not the other species that remain. We breathe, turning all that carbon that we have changed from forest to crops, into CO2. AND SO IT GOES ON. And it will continue to do so. We fight disease, preserving life, we extend lifespans, increasing numbers. We even extend the reproductive period with people of 60+ giving birth and starting families. All of these consequences result in stress and strain on the environment.

Which brings us back to the flip flop of Government policy. Diesels are good; until electric cars become more readily available as a commercially viable norm, until they can be charged without recourse to fossil fuels from sustainable electricity generation using wind, solar, or wave, power. Diesels produce less CO2 than gasoline engines because they produce more power at low revolutions, which is why they are used in large commercial vehicles, boats and trains. CO2 is the key parameter to control at the moment. So as CO2 increases, global warming continues and subsequent rise in sea levels exert the main threat to our civilisation at the moment, the move should be towards Diesel not away from it. Ah! I hear you cry, what about the pollution? What about NOX? And here VW have a lot to answer for, in that they met the standard test requirements for emissions by using smart software – a solution that everyone knew about for YEARS. It shows that the engines can meet the requirements of low emissions, if driven correctly. But driving that way makes the performance unusable: it is a standard cliche that the biggest component relating to fuel consumption (and hence emissions) is the nut behind the wheel. Programmes on TV, some featuring Mr Clarkson, show it is possible to drive long distances on a single tank of fuel in a standard (diesel) vehicle – London to Edinburgh and back: Switzerland to Blackpol, both on Top Gear. But it is not in line with human nature to drive that way, to not have the radio on, to switch off the heating and not to accelerate in a way that maintains normal progress. So a VW software that mimics what humans can do, it they chose to, showa that diesel cars can control emissions! But not as they are normally driven. And that “revelation” is bad and has led to a rapid decline in Diesel sales – and an increase in CO2 accordingly. An alternative exists in that some cars – my own included – inject urea into the exhaust so that the urea reacts with the NOx (NO2) to produce Nitrogen (80% of the atmosphere) and water, generally regarded as non-toxic. So alternatives exist that will cut down on CO2 – our major threat, and also eliminate the NOx which can potentially cause lung irritation if it dissolves in the liquid lining the lung and form nitric acid: ignore the fact that pregnant women in childbirth are given Gas and Air to moderate the pain of labour and that the Gas is nitrous oxide (N2O – not generally deemed as a NOx gas, but hey) or that nitric oxide (NO, classed as NOx) is sold as a supplement on Amazon and stores in the High Street and is an essential mediator in human biochemistry, NO2 which can form nitric acid, is the gas of concern. The EU Limit is 40 micrograms per cubic metre of air over a year on average with a 24 hour limit of 50 micrograms per cubic metre. ( The WHO have produced a review of nitrogen oxides which states the risks that exist as far as human exposures are concerned, the conclusion is reproduced in full below:-

As can be seen, the WHO suggest a 1 hour limit of 200 micrograms per cubic metre of air, is safe for the general population, but that the standard air quality value of 40 that was proposed previously by WHO in 1997 (Ref 143), based on levels that are considered to be safe for children with pre-existing respiratory illness (asthma) should remain.

So, the limits are set to protect children with asthma. Diesels can produce no NO2 if the exhaust is treated with urea, and yet because there have been changes in software to mimic the driving habits of Jeremy Clarkson – when conducting a long term fuel efficiency trial, and not normal driving, there has been a move away from diesels to cars that have in a matter of months, led to an increase in CO2 emissions. CO2 being a greenhouse gas that will lead to global warming, which is in danger of melting the permafrost and thus releasing an inconceivable amount of methane into the atmosphere: methane has a greenhouse gas effect orders of magnitude greater than that of CO2. This will definitely make diesels redundant as we will be all moving to boats powered by 2-stroke outboard motors in order to get around.

It is not simple, and knee jerk reactions are not appropriate. We should not be formulating policy on really important issues based on sub-editors and headline writers.

Rant Over.