It is to be regretted that a chemistry graduate, Dr William Flood, has so haughtily dismissed the developments being demonstrated by Air Fuel Synthesis (AFS) at Stockton-on-Tees (letter, 20 October).
Had he done the simple thermodynamic calculations underlying the process and assessed the positive environmental implications alongside the chemistry, he would know that the cost of producing the petrol is no drawback.
A back-of-an-envelope calculation shows that if AFS has an efficient catalyst to facilitate the reduction of carbon dioxide to hydrocarbons, and we must assume it has, then the energy needed for that process and for the production of the hydrogen that is required is the same as the potential energy contained within the petrol product, i.e., from production through to consumption it is energy null.
Some energy will be required for separating the carbon dioxide from air. However, the overall process is evidently clean and consumes the same amount of carbon dioxide that is generated in the subsequent use of the product fueling road, rail and air transport, and oxygen is produced as a saleable by-product.
As more of our electricity is generated from non-fossil fuel sources, the real advantage of such technology is the potential for building an energy economy that would be overall non-polluting.
No industrial chemical process is ever 100 per cent efficient, but, based on similar considerations, perhaps Dr Flood should assess the production of petrol from the other sources for which he suggests chemical ingenuity might devise processes: coal, wood or even old socks. All would be net energy consuming processes and result in the generation of yet more polluting carbon dioxide. We should all wish AFS every success in its endeavours.
Richard G Jones
Emeritus Professor of Polymer Science,
University of Kent, Canterbury
What a great discovery! What could be kinder to the planet we live in than making fuel from CO2 taken from the air? We have hardly started to think about what petrol from air could do to facilitate large-scale production of solar energy.
Solar energy (making steam to drive turbines) has been produced on a commercial scale in the deserts of California for 20 years or more. Without subsidies, it has proved fully competitive with electricity from fossil fuels. Unfortunately, the world's deserts are generally far from where electricity is needed. So except for California (which has Los Angeles right there in the desert) solar power has not been able to make any headway.
Petrol from air could change all that. At last we've got a way to make solar energy transportable and marketable. Probably too expensive for other uses, the technology could really come into its own when driven by cheap solar power in the desert.
It has been calculated that all the world's energy requirements could be met by solar energy installations covering an area the size of Austria – in other words, covering a tiny fraction of the Sahara and other deserts. Let's give up our present expensive struggle to reduce CO2 emissions, and start building power stations in the desert.
Remember the British Army's biggest victory
On behalf of The Western Front Association, we welcome the Prime Minister's announcement of £50m to commemorate the First World War, and particularly the emphasis on education: it is vital that younger generations understand the events that did so much to shape the world we live in.
However it is disappointing that so little emphasis is placed on the events of the "Hundred Days" of August to November 1918. In that period, in concert with Allied forces, the British Expeditionary Force (which included Australian, Canadian, New Zealand and South African troops, as well as soldiers from other parts of the Empire) won what were, in terms of scale, the greatest military victories in our history.
While it is right and proper to remember the failures in the earlier part of the war, it is highly appropriate that in the centenary period the United Kingdom should commemorate the battles that won the war. This is not a call for triumphalism, but for proper recognition that the sacrifices of the dead of the First World War were not in vain.
We therefore ask that a commemoration day, along the lines of the one that will be organised on 1 July 2016, should be held on a suitable date in 2018 such as 8 August or 29 September.
Professor Peter Simkins
Professor Gary Sheffield
Dr John Bourne
The Western Front Association
Professor Hugh Brogan (letter, 22 October) is right that it is time to study the lessons of the Great War and that this should "not result in yet more sentimental wallowing in memories of the Western Front and its horrors" but, rather, give us the opportunity to "use the centenary to rededicate ourselves to building a world order of peace and justice".
There is only one point that I think we should consider as we look back at the wars of the 20th century – that the Second World War was not really a separate conflict but, in reality, a continuation of the First, after a lull, not entirely free of conflict, of 20 years. Perhaps it would be profitable for historians to consider the whole period as a parallel to the "Thirty Years War" some 300 years previously, with which it has many common features.
Martin D Stern
Salford, Greater Manchester
If my father saw through Savile ...
My father used to run a music shop in Penzance. In the 1970s Jimmy Savile stopped in while running from Land's End to Scotland. My father met him in the morning, before having lunch with us excited children. My father said: "Jimmy Savile is a deeply worrying person who should be watched when with young people." We were not allowed to watch Jim'll Fix It from then on.
My dad met many stars of the pop world, including the Sex Pistols and Queen, as they passed through Penzance, and was very impressed with them as people, even though, or perhaps because, he was a staunch Methodist. So if he was concerned over Savile after a 10-minute encounter, why did the BBC bigwigs in distant London fail to see, or turn such a blind eye, and with such a depraved outcome?
John Simpson thinks the Savile case is the BBC's worst crisis in 50 years. The Andrew Gilligan affair and the Hutton enquiry of 2003-4 was much more serious. The BBC's capitulation then in the face of government bullying surely brought about the culture of editorial timidity that is causing such terrible damage to it now.
Steeple Claydon, Buckinghamshire
Will badger cull work?
Chris Packham quotes me as saying that badger culling "won't solve the problem" ("Vital cull or heartless slaughter?" 9 October).
In an interview with the BBC which appeared online on 17 September I said: "Culling won't solve the problem nationally [across England] ... But farmers in Devon, Cornwall and Gloucestershire are arguing that it can get between a 16 per cent and 20 per cent reduction, which they think is significant and that they are willing to pay for."
I added that culling was not a solution on its own, but needed to be combined with other measures such as improved cattle control and continuing our efforts to achieve workable badger and cattle vaccines (areas in which Defra is continuing its work).
It is disingenuous to suggest that I was one of "our government's most respected scientific advisers ... queuing up to point out the fallacy of this cull", as Mr Packham claims.
Professor Sir Robert Watson FRS
Racism kicked out of football
Yasmin Alibhai-Brown's arguments on racism in football (22 October) seem to be based more on her dislike of a game enjoyed by the working classes than on the facts of the situation.
As a football steward I am ever conscious of my responsibility to help combat racism, but find that awareness is such at football grounds now that crowds are mainly self-policing and would certainly report any on-pitch racism too. The Kick Racism Out campaign has been a wonderful, widespread success and at the vast majority of grounds racism simply isn't tolerated.
Dose of reality
Richard Walker (Letter, 19 October) undermines his own argument in favour of cyclists and other athletes being allowed to take performance-enhancing drugs "approved and regulated by their governing body". What happens with the soon-to-be-invented and much better drugs that aren't approved or regulated, especially when the athlete who is benefiting from them doesn't want anybody else to?
As an advocate of English independence, I wish the Scottish people the best of British with the referendum. Once Scotland has independence I wonder how many Westminster MPs of Scottish descent may consider returning to serve their newly independent country as MSPs.
Woodford Green, Essex
A man gets six months in jail for interrupting a boat race. Rather than further clogging up our overcrowded prison with yet another nonviolent protester, would not this have been much more proportionately dealt with by a fine or community service?
David Cameron's ignorance of history obviously extends to the heady days of Conservative privatisation of gas and electricity distribution. Had this not happened he would have been able to set prices instead of making undeliverable promises.