Moving energy production to renewables is the easiest part. Much more difficult is the part where we need to do something about the few billion (and rising!) gas-guzzling personal automobiles. Electric cars are simply not going to be the solution in the timeframe that matters. In the EU traffic is the only major CO2 source that continues increasing. The third big problem is agriculture, specifically meat production. Two to three billion new people who have traditionally been mostly vegetarians are now hungry for meat, and the planet simply cannot afford such a thing.