No.

It's totally unethical. They are convincing the kids that we need to change to save the planet. We can't save the planet. We need "them" to stop spraying us with chemicals....that would be a good start.

It’s interesting, I watched the first two minutes of that program before I was hit with the first of Attenborough’s climate propaganda and immediately turned it off (as I do with many shows these days), but I often wonder how many people will just accept this rubbish and not even realise they’re being subjected to (most likely false) information and a hidden agenda.
In short yes, I agree, it’s unethical, especially where children are concerned.