The role of the judiciary is to clarify the grey areas left open for interpretation by the legislature. While none of these countries have passed "F off young people" laws I don't think it's fair to say the majority of these rulings (except the dutch one - that one is legally interesting) are really a reasonable interpretation of laws on the books.

That all said, times are desperate so if law makers are going to stick-in-the-mud I'm happy to see them overruled by the will of the people. I feel like we've gone past the point where we can reasonably discuss alternative market based solutions to climate change like carbon credits - and most conservative political blocks are still against even such a soft idea.

At least in the German ruling of the constitutional court they could refere to Article 20a of the German constitution

Art20a, Roughly translated: The state, in responsibility for future generations, protects the natural means of subsistence and the Animals in the constitutional order by use of legislative, excecutive and judiciary measures.

Of course this doesn't say verbatim to protect the climate but I think this is enough legislative basis to rule dangerous negligence on the matter of climate change unconstitutional.