1 and 2 I don’t know. I don’t like monkeys so I have never thought about such things.
2 – N2 is atmospheric nitrogen or just molecular nitrogen N-N (with triple bond of course), I think.
3. We can’t say for sure that every species of animals will have become endangered within that period. We may only suppose.

1. hy r u asking such monkey funkey questions…
So…see a deep study is going on this topic but what is the common thing is just they can if we teach them perfectly!
They can speak but not like a normal person but only that what we teach them upto a limit.

2. The voice cords matter. If they r absent then we can’t speak but then our brain would evovled to make some complex behavioural or symbolic laungauge and it could resemble to that of monkeys…may be..not sure!

3. Global warming ..we can’t predict what will occur at what time…so just be cool!

It seems fairly unlikely that all animals will become extinct but some might. Most would probably move to a cooler region or just addapt to the environment.

I think its a slim chance of all the animals being endagered due to global warming. evolution is taking place as we speak so there will be new kinds of animals emerging. so dont worry i dont think we’ll be the only species left on our planet.