COP26: What's the climate impact of private jets?
There has been criticism of the number of world leaders and other delegates who have travelled to the COP26 summit in private jets.
How much environmental damage do they do - and did leaders have any choice?
Plane spotters at Prestwick Airport in South Ayrshire have been enjoying the unusual range of aircraft arriving there.
And it hasn't just been those ferrying the leaders themselves - there have been cargo aircraft arriving, carrying helicopters and vehicles for motorcades.
We know, for example, that President Biden has one of his armoured vehicles,...