“There is a place in Oxfordshire … on the verge of creating commercially viable miniature fusion reactors for sale around the world delivering virtually unlimited zero-carbon power”, Boris Johnson, Conservative Party Conference, October 2019

“We do not need to change our lifestyle, but we do need to invest in technology to combat climate change”, Labour candidate, Reading, November 2019

As we vote today, the biggest issue on people’s minds is likely to be Brexit.  This is sadly out of proportion, because the biggest issue facing us, and certainly our children, is environmental decay including climate breakdown.

While it will be drowned out in the British media by the national election results, an arguably more important event is taking place: the international COP25 Climate Conference in Madrid.  There, the head of Greenpeace International, Jennifer Morgan, found herself locked out of the talks yesterday along with hundreds of observers, an expulsion that was without precedent in COP conference proceedings.  With plenty of precedent, however, has been the refusal of the major emitters to commit to anything meaningful. “Frankly, I’m tired of hearing major emitters excuse inaction in cutting their own emissions on the basis they are ‘just a fraction’ of the world’s total,” said the prime minister of Fiji, Frank Bainimarama.

But everything will be OK, because new technology will save us.  So we don’t really need to worry about climate breakdown, at least not excessively, providing we support our talented scientists.  That appears to be the attitude of both main British parties, and by implication a large proportion of our general population.  Alas, blind faith in science in the 21st century has the hallmarks of blind faith in spirits during the middle ages.

The Culham Centre for Fusion Energy, about which Boris Johnson waxes lyrical, is more cautious about its own prospects.  According to its own website: “fusion is expected to become a major part of the energy mix during the second half of this century.  With adequate funding, the first fusion power plant can be operating in the 2040s.”  It would be reasonable to expect them to be at the optimistic end of the spectrum.  It is notable that fusion is rarely mentioned at all in the standard energy press.  And, of course, the second half of this century might be too late, as we might be in the throes of runaway global warming by then.

By all means, let’s support interesting technologies.  But simply to assume that scientific solutions will be found, when they have not yet been found, is profoundly unscientific.

In August, Professor Ian Boyd left his position as chief scientist at Defra with a stark warning: the government must implement policies to encourage people to change behaviour and consume less.  If we do not get resource consumption under control, we will not get emissions under control, he said.  On this topic, amongst others, I would trust his opinion more than those of Boris Johnson and a local Labour MP.

Blind faith: a case study

Within the last couple of years, there has been an interesting development in the relative impact of different sectors on our climate footprint. The direct emissions of CO2 from flights arriving at and leaving from Britain’s airports are, in aggregate, now 70-80 Mt per annum. This total is more than the emissions from Britain’s power stations, around 65 Mt in 2018 (as published by BEIS). One could argue that only half of those flight emissions should be attributed to the UK; equally, one could argue that the greenhouse impact of those flights is significantly larger if non-CO2 effects are taken into account. What is clear is that the global warming effect of British aviation is now comparable with the global warming effect of our electricity generation.

Really? How does this result square with the claim, beloved by the aviation industry, that aviation only accounts for 2-3% of global carbon emissions?  Well it’s partly because of good progress in the power sector.  But it’s also explained by the fact that in Britain we fly 5 times as much, as measured in terms of airmiles per capita, as the global average.  We account for 4% of aviation emissions but have less than 1% of the world’s population.  Most people in the world don’t fly.  Chances are they want to catch up – and growth in aviation appears to be outstripping the UN’s own forecasts.

The blindly faithful have a range of solutions superficially to hand: biofuels for aviation, electric planes, hydrogen planes, lighter planes, more efficient planes.  Let’s consider these in turn, briefly:

Biofuels: in order for biofuels to offset our CO2 emissions from flying, fast-growing coppice needs to absorb CO2 at the same rate as it is emitted by aircraft.  Without repeating my discussion of this from a previous post, we would need to cover 20-30% of our island with such biomass dedicated to the purpose.  This would mean tripling our current level of forest cover.  Where is the land going to come from?  We would have to re-assign some of the land used for agriculture (about 70% of Britain’s total area).  The most realistic such re-assignment would be to reduce our meat and dairy herds.

Electric planes:  I have tried to elicit views as to whether it is physically – let alone technologically – possible to design an electric plane that will fly over an ocean.  Those who have answered, including Martin Rees, think probably not.  One difficulty is the weight of the battery is about 50-100 times as much as the weight of the corresponding volume of jet kerosene, so it is difficult to see how an electric plane destined for New York, say, would ever get off the runway.

But let’s suppose that these respondents are too pessimistic and we get electric planes in future for long-haul as well as short-haul flights.  Given the trends in consumption, and the fact that electric planes would be heavier, we might have to double our electricity generation to meet the demand.  Possible?  Yes, but certainly non-trivial.

Hydrogen planes: hydrogen may be produced from electrolysis (using electricity) or from methane reformation.  If we use electricity, the increase in required generation is even greater than for electric planes, because the most efficient processes for making hydrogen yield 60-70% as much output energy (in the form of hydrogen) as is input.  If we convert methane, we would have to increase our natural gas consumption by maybe 30-40%.  This of course would be counterproductive unless we capture the greenhouse gases from the conversion process.  To date, carbon capture and storage has been too expensive to be developed to any significant extent.

Lighter planes: the aviation industry has had around 50 years of strong commercial incentive to make planes light in order to save fuel and hence money.  But let’s suppose a miracle occurs and new materials are developed that halve the energy expended to combat gravity.  Because planes use around half of their energy combating wind resistance (as opposed to gravity), that miracle would only reduce fuel consumption by one quarter, unless we are prepared to travel more slowly and take longer getting to our destination.  Actually, travelling more slowly is probably part of the answer.

More efficient planes:  again, the commercial incentives on the airline industry have made planes pretty much as efficient as they can be.  There is a limit to how good a gas turbine (jet engine) can be.  The late David Mackay, author of Sustainable Energy Without the Hot Air, wrote that he would eat his complimentary socks if plane efficiency were to be doubled in future.  I suspect that even had he lived to a great age, he was safe enough from cotton consumption.

I hope this aviation case study conveys some idea of the scale of the challenge; and why I have concerns about the flimsy rhetoric of (many) politicians.  One could pick on other aspects of consumption – heating for homes, car transport, goods manufacture, diet – and show for these also that the future is pretty challenging.  Especially if we are determined not to change our lifestyle in response to the “emergency” that those who should know best are telling us exists.