Heatwave

In July the highest temperature ever recorded in the UK was observed at just over 38C on Thursday 25^th..At the same time continental Europe was suffering even higher temperatures while the central USA had had bouts also of unusual heat and there is drought in Australia. Shortly after parts of the UK saw very heavy rainfall which led to flood problems plus damage to a dam in Derbyshire. The physics is that hot air can hold more moisture but is less stable.

For a long time climate change deniers have been…. well denying. However the realisation is slowly dawning that these events are not the natural extremes. Climate scientists still cannot say that these extreme weather events are 100% caused by climate change; what they can say is how the odds on such events is increased with climate change. It is a fact that it is not just this summer but 9 out of 10 hottest July months have occurred in the past ten years.

At the other end of the spectrum just as was forecast there has been an increase in severe winter storms.

It seems to me that the evidence is now so plain and overwhelming that the reality of climate change is being accepted. Not by the terminally stupid liars like Trump. Not even sadly by Jair Bolsonaro the new Brazilian leader who wants to destroy the Amazon rain forest. While there are holdouts I think ( hope ) they are getting fewer and lacking credibility.

A paper claiming that climate change is caused by small differences in solar input has been shown to be severely flawed. Essentially it claimed the distance of the earth from the sun was changing slightly which has been shown to be wrong. Deniers have used papers such as this to try to sow fear, uncertainty and doubt ( FUD )

I do notice that other more visual issues are getting more publicity. While it is entirely right that the problem of plastic waste in the sea gets attention it would be bitterly ironic if this was at the expense of the far greater issue. What climate change needs are some cuddly pictures similar to those on Blue Planet..

It is trite to say that fossil fuels are the problem and big oil is the villain. The truth is that we are all villains for demanding and using fossil fuels. The way forward is becoming clearer. Transport need to be electrified with electricity generated by renewable sources. For the UK this means mainly wind power. On shore wind generation is now cost competitive and off shore wind approaching competitive with coal generation. Back up generation capacity will be needed and for a transition period combined cycle gas turbine looks the best bet. Longer term is less clear but wave or nuclear look good possibilities.

A more uncertain prospect is fusion power. Essentially this means a sun on the earth. A massive international program is based on ITER, a prototype facility in the south of France where almost all technically advanced counties have pooled their resources. The objective of ITER is to produce more power than is consumed in making it work. ITER is massive, over 70m high and costing many billions. There is some scepticism about the prospects for fusion power; the joke is that fusion power is 30 years away and always will be. This reflects the difficulty of retaining and controlling a plasma at a temperature of many millions of degrees. It is an encouraging sign that a few private companies have entered the field.

The more down-to-earth problem is that liquid fuels such as petrol or kerosene are excellent sources of concentrated energy. In contrast batteries are fairly heavy per unit of energy supplied. While there are small gains to be made in battery technology there is no great step change improvement in sight.  Research is continuing at a furious rate and there are some interesting possibilities .

 I find it interesting that electricity is now taken seriously for aviation. Already small electric aircraft are available. For commercial aircraft the way forward being explored is the hybrid where a gas turbine generates electricity which is then user to power electric thrusters. This relies on the gas turbine being small and running efficiently at constant speed while batteries supplement during take off and climb.

For larger aircraft ( wide bodied ) there is no substitute for liquid fuel. The hope here is for fuels made from renewable sources.. The technical difficulty is that while regenerative braking helps recharge car batteries there is no equivalent for aircraft. As I say above the general plan is to use an onboard turbo generator working efficiently at constant output using batteries to the full on climb out and recharging as the  aircraft descends. This would only be practicable for fairly small aircraft , say 50-100 seats.