As long as we are stuck on this rapidly overcrowding mudball I don't think things will turn out as rosey as you think.
Here come the techno-philanthropists...Google execs and James Cameron are already planning on mining asteroids...one small step. Space has resources and...space! All doom and gloom predictions of Earth's dwindling resources and over-population do not account for exponential technologies, or space tech. Virgin Galactic (originating from the X-Prize)can also make space more commonplace, giving people on Earth the sense that it's less dangerous. It could lead to more projects in the future. Looking further ahead, I've posted about smart matter...eventually if there is a singularity AI on Earth spreads into space.
Overpopulation...statistically, countries and regions that are poor tend to have higher birth rates. It's a fact as industrialized nations become more advanced the reach a population equilibrium, and the birth rates go way down. This is already happening in third world countries in the last few decades...the bottom billion are slowly making it up the ladder. China basically had a 3rd world economy till recently, the statistics are staggering! China now has tens of millions of people who have come out of poverty in the last decade.
Energy: There's a reason why energy was such a big part of my top 5 future technologies. I've been researching nuclear power. Needless to say the world is down on nuclear energy, and I'm not a fan of 3rd generation reactors myself, but there are some newer alternatives, and 4th generation reactors may be activated by 2030. The ITER and DEMO project for nuclear power could eventually make a working fusion reactor by 2030-2040. These can supply the world with brute force power in those years, and they are relatively clean. Solar energy and clean energy ARE able to meet our energy needs if we take advantage of them. Japan seems to be slowly eliminating its nuclear energy program for wind power. Fukushima will have offshore windmills where the nuclear plant used to be. The world is not
going to run out of power as fossil-fuel resources run out(and they will). This is a fantasy made up by activists.
Well rosey is a strong word, there are different ways this exponential future can go, and I cant say with all certainty humans will be on the better side of it, but the potential is there. While most people today look forward and see negativity, I see possibilities. Now we have the means to make those possibilities happen, we just need to move forward with it...and in some cases, as with the techno-philanthropists, innovative companies/start-ups, and organizations like the Singularity University, they are making it a self-fulfilling prophecy by doing the work it takes to get there.