7 April

Here’s an international traveller, standing next to roughly how much fuel it takes to transport them - just them, per person - from (say) Australia to Europe. That’s one-way. They need the same tonne-cube to get home again as well. Combustion engines, including jet engines, are grossly inefficient. About 1.2 tonnes of that roughly 2 tonnes each passenger needs to get there and back goes straight out the exhaust of jets, unused.