So hypothetically, if all developed countries suddenly decided that it was worth whatever the cost, could we get to 100% renewable in say.. 10 years? How much of our activity would need to be directed at this? Not even research, if the plan was just make as much renewable energy as we can with current methods as fast as we can.

Of course this would never actually happen and we're in all likelihood gonna continue to trash the place, but is this possible even in theory?