> Depending on skills and technology, they are not scarce for a world population of 10 billion humans or they are scarce with a world population of 1 human.
This is very true. If organized properly we could very easily feed the 7.7 billion people that live on earth today. We could easily feed the 11 billion people that are expected to exist in about 50 years or so on earth. I do not doubt that the technological hurdles are gigantic, but the could be overcome.
Alas, I don't see that happening. Not because of the technological difficulty, but because of human stupidity or shortsightedness, our tribal instincts and the tendency towards reckless acquisition of resources that allowed our ancestors to become the dominant species on this planet in the first place.
You see, the problem is not our abilities to change the environment. The problem is our inability to change ourselves.
/If/ we all went vegan, /if/ we stopped needles, wasteful wars, /if/ we stopped consuming more than we need, /if/ ...
... then we could make it. But we don't change our behavior. We are still greedy little apes that are driven to resource acquisition to improve our social status in order to have higher reproductive success. We are reproduction machines, nothing that is changed by a few decades of wealth in some parts on earth.
It is this inability to overcome our biological imperatives that will doom us, because they prevent us from recognizing the foreigner as our sibling. And so we compete for resources, even though we've already so many resources that we die from over saturation.
So, unless all the peoples around the world start working together very soon to combat climate change, mitigate species and biomass loss, reduce the consumption of resources to a degree our planet can actually provide, I don't see how the human species will be able to survive.
It's not that we couldn't do it. It's that we're not willing to pay the cost in the /now/ to be able to survive in the /future/.