Why is it unhelpful to point out the fact that we're overlooking the root cause of the current problems? Of course I would love to have provided the solution for world's overpopulation as well but I admit that I don't have it. Yet, somebody else here might.

In my opinion you're putting the bar way too high if you require anybody on this forum to only reply to a discussion when he/she not only can point out a failure in the arguments but has the correct solution as well.

Finally, you are putting some rather dubious solution in my mouth with your comment "What is your point? Should we kill everybody over 70 years old?". Of course I didn't have that solution in mind.

There is overpopulation. We just had earth day and looking at a graph about population growth is a very clear hint.

It is true that this is nothing we can change, but the source of the problem shouldn't be ignored.

Of course we can eat as much meat as we want. It just doesn't scale to 7 billion people.

So yes, there is overpopulation, we just cannot do anything about it. But don't dismiss the fact.

GP said the rest of the discussion is about a temporary solution, but in the longer run overpopulation is the root cause which needs to be addressed.

I don't agree that overpopulation is the root cause, and I'm not a fan of talking about it much either. However, assume for the sake of argument that it is:

Reducing Earth population in the long run doesn't have to involve harming anyone.

For example, we could use changes to politics, technology and culture to provide better skills, education, even healthcare and assisting the old to live longer, and assist with more fulfilling lifestyle aspirations, and generally empower as many people as we can to lead happier lives.

Much of the scientific study we have suggests that will both reduce world population and improve quality of life across the board, because of how humans make choices about reproduction.

Nobody needs to be killed, nobody needs to have medicine withdrawn, nobody needs to be sterilised or even discouraged from having children. No odious racism or elitism or eugenics is required.

It's enough, to just improve lives, and it looks very much as though humans may naturally reduce their population replacement rate in the long run.

So that leaves only the climate problem in the shorter run, for which "temporary solutions" could be good enough.