I wish to express my support for Amendments 39 and 49. I have been looking for a place to make my interjection, which ought to have been encapsulated in an amendment, but perhaps I should propose an amendment at Report. However, now is as good a time as any to air my suggestions.
Aviation contributes significantly to emissions of carbon dioxide. These emissions do not approach the level attributable to road transport but, nevertheless, they must be eliminated. It may be possible to replace short-haul aircraft with aircraft that depend on battery power, but long-haul aviation cannot be electrified. It will continue to depend on liquid fuels. It has been suggested that the fuel could be liquefied hydrogen, but this seems be impractical. Conventional hydrocarbon fuels have an energy density that greatly exceeds that of hydrogen, which is difficult to store in a liquid state and demands considerable storage space. Jet engines that burn hydrogen have not yet been developed.
It seems that hydrocarbon fuels must continue to be used in long-haul aviation. Eventually, this will be acceptable only if the carbon element of these fuels can be sequestered from the atmosphere and the hydrogen element of the fuels becomes green hydrogen. When
such fuels are burned, their carbon element will be returned to the atmosphere. Moreover, the use of green hydrogen, as opposed to the so-called blue hydrogen derived from the steam reformation of methane, will mean that no emissions of carbon dioxide will come from this source. To manufacture aviation fuels derived from the direct air capture of carbon and from hydrogen generated by electrolysis will require a huge input of energy. Sufficient energy would be available only if we were able to depend on nuclear reactors to provide it. Such synthetic fuels will be costly to produce; unless they are subsidised, they will be unable to compete with petroleum-based fuels or fuels derived from biological feedstocks. However, biofuels have a high opportunity cost, since the production of their feedstock is liable to pre-empt the use of valuable agricultural land. They are therefore best avoided.
We need to support the development of carbon-neutral synthetic aviation fuels. I propose therefore that, in the first instance, they should be allowed to incorporate green hydrogen as well as carbon not derived from direct air capture but captured from fossil-fuel emissions. In time, both these allowances would be abolished.