As we know, the main propellant of conventional aircraft is kerosene. Recently, this fuel has already been produced synthetically (green kerosene), but it is very expensive to produce it, and considerable energy is needed to supply it to airlines in sufficient quantities. The ecological footprint of the fuel used and its production would be the smallest if it were produced from water and carbon dioxide in the air and with alternative energy. This could make the flight completely carbon neutral. The biggest problem to be overcome is that the production of synthetic kerosene is currently 3-6 times higher than the traditional fossil production method. The cost of producing environmentally friendly fuel would increase air fares by up to 60%, which could discourage many from this form of travel. And a reduction in passenger traffic would put more airlines in a bad economic position.
The essence of green kerosene is that it is produced from water by mixing it with carbon dioxide in the atmosphere during physico-chemical processes. Thus, the fuel would practically come from what it becomes during use. That is, green kerosene is actually a renewable energy source. Using a large amount of energy, it can be broken down by electrolysis into the constituents of water, i.e. hydrogen and oxygen, which can be combined with carbon obtained from carbon dioxide to be converted into synthetic kerosene. The energy required for the process is what actually makes alternative fuels extremely expensive. To overcome this, it is necessary that sufficient electricity is generated using renewable energy sources. Considering the technologies known today, the cheapest alternative way of producing energy is to use solar systems. And as you know, solar panels have a number of advantages, the most important of which is that they produce large amounts of energy without polluting the environment. Thus, the mode described above is the only way for aviation to become carbon neutral in the future.