I believe 10 billion people + could be supported because the current troubles of the world in terms of hunger and poverty is principally because of inadequate DISTRIBUTION. To put it simply the rich countries are consuming way too much. Therefore humans can be supported IF worlds resources are distributed more evenly.
Technically speaking, the earth probably could support the lives of 10 billion people, but we would have to make changes to the way we live and the way we allocate resources among them. It would make us take a look at the land we have and how we use it.
There are already 7 billion people currently alive today and while we do face many problems because of this I think the planet could support an additional 3 billion people, I would say that there would be more food shortages and more war in general because of overpopulation problems but the earth could generally support it.
Yes, I believe that it is possible for 10 billion people to live on Earth, because we would find ways to grow more in smaller places. Urban farming is on the rise. There would be changes to grow crops more closely together. People would live in apartments rather than in large houses. It could work.
Yes, I do think that it is possible for that many people to live here on Earth, but I think that things are going to get a whole lot harder when they do. I think that we are going to start running out of food and thing like that here.
The Earth is already in serious trouble by the way we are treating it. We are taking resources at such a rapid rate that someday soon we are going to realize we have done far too much damage that what can be repaired. We should of been using solar and wind energy for years now is a much greater scale, but we haven't. Too many people are in the pockets of the oil and gas companies.