I'm afraid that eventually, as long as population grows, we'll hit some hard limit. For now, technology is (barely) allowing us to fall into Maltusian wars.
But the true issue is a bit on what you said. Long terms solutions that might take decades to be a solution need to be taken now. Take fusion power, for example. I've seen scientists quoting 80B and 15 years for 15 years. They were never funded because it was too much into the future. I'm sure it will cost something like 200B and take 25 years to have the first fusion reactor. But that's not bad. If you could know that in 50 years 90% of your energy production would be fusion, you only need a transition plan. A lot of nuclear plants would be a great help, for example. And the cost is not that much. Say that you want to convert all the fuel pumps to electric chargers, that's something like 100B. How much was the Integral Fast Reactor until fully developed, a few Billions? Replacing every coal powerplant with nuclear, that's 1,750B.
To put an example, that I'm afraid will ignite some nationalistic tendencies here, the Irak invasion (2003-2011) cost, directly 845B. And it cost the USA economy some 3B. Had you not invaded Irak you could have probably developed fusion power, converted 60% of your power plants to nuclear and have one third of new cars electric. Had you also had spent the stimulus package on perfecting the IFB technology and deployment, you could have converted the whole non renewable power plants to fourth generation plants and developed nuclear fusion.