I am optimistic about our future in this planet and also for our existence in general. Technology is going to find a solution really soon but its a race against time. We have already witnessed glaciers melting and the increasing volatile weather around the world . The Balkans have recorded their worst floods in 130 years minimum and north America is facing droughts etc . But as time passes we are going to find a solution for global warming.As for the population. Well earth is big place and my guess is that earth will be able to sustain 30 billion people If we are really orderly. But then its comes down to industries and carbon emissions. That would really be disastrous on that scale.
The Population Clock indicates that there 7.2 billion people in the world. 10 billion, on that scale, simply is not that much more. It sounds like a lot, but the planet is large, to us anyways. I think the population will bypass 10 billion quite easily, we're almost three quarters of the way there.
It is possible for the planet to sustain 10 billion people on it at one time. I think that this planet is getting crowded and that the more people you put on it the pollution and troubl ewill become of it. I do beleive that the planet could probably hold that much but at what cost.
Yes, it is possible for the planet to sustain 10 billion people, because most of the planet is still undeveloped. So much of the planet is undeveloped that we cannot even find one airplane in the middle of Asia. We would find better ways to farm and we would modify crops to meet our needs.
The planet earth cannot sustain 10 billion people at the current levels of world consumption of resources. Energy, food and water resources would not be available to all ten billion people for basic sustenance. Water and food resources are critical for all life. Too much of the planet's resources are being utilized for the production of unnecessary consumer goods.