"and there'll be no life on Earth at all"

 An exceptionally bright bunch of children in 1966, so very worried about the future. 

Common anxieties - world destruction, automation, computers, homogeneity, ugly modern buildings, overpopulation and overcrowding, robots,  battery farming, food pills, boredom. 

"I'm not looking forward to living in 50 years - there'll be machines everywhere"

"I think it's going to be very  boring, and everything will be the same, people will be the same."

"I think it will be very dull and people will all be squashed together so much there won't be any fun or anything. And people will be rationed to the number of things they can have."

"Very cramped"

" I don't think it'll be so nice - sort of machines everywhere. And you'll get all bored"

There's one kid who presciently worries about the sea levels rising and England becoming an archipelago of formerly-higher-ground islands.

Another who frets about a new Ice Age. 

A couple of girls who think because of overpopulation, a lot of people will have to live under the sea.

A rare note of curious optimism - a kid looks forward to curvy not square buildings (a young Archigram fan?)

The big difference between then and now is the disappearance of the fearful expectation of nuclear war. 

Plus ça change....   the worries and dystopian-scenario triggers today for kids would be largely different (pandemics, climate crisis, AI, terrorism, microplastics, declining birth rates, fascism)  but I expect the anxiety-levels are roughly the same. Perhaps made worse by the doom scroll and the access to information (although the kids in the 1966 film seem very well informed). 

I wonder how many of these kids are still alive (they'd be in their early seventies now)? What worries them today and how do they picture the year 2074?