no matter how good human ingenuity is, it won't solve the fundamental problem, which is population overshoot. The earth cannot support this many people indefinitely, and certainly not to the ideal middle-class standard we see in the west. Something's got to give, sooner or later.
I would like to believe that renewable energy will solve the problem, but it still doesn't address the central issue, of too many people on an earth with finite resources. Even if we completely replaced fossil fuels with renewables, that would require massive infrastructure. Imagine how many solar panels and wind turbines you would need to power, say, Manchester? And even if it was feasible to do, those panels and turbines need to be built and maintained, which involves large-scale polluting mines and manufacturing, so we are still destroying the earth, and mines are finite, anyway. There is no way to get around this.
And even if we solved the energy problem with cold-fusion or something, it still doesn't solve the soil issue, and the myriad other issues that our kids will have to face up to over the next 40-60 years. It's all horrifically scary.