Earlier quoted context omitted.
Of course there is the option to use less energy. That's just silly. If you are an American, go to any other country to learn how to get by with less energy (ie smaller houses that require less heating, smaller cars that use less fuel, less commuting to begin with, smaller fridges,...).
In theory, there is such an option. In practice, no one will take it, because why should they? It's both a coordination problem and a short/long-term values problem. How do you convince an average Joe to reduce his quality of life now in order to secure some abstract better future later; a future, that will come to pass if and only if every other average Joe and Jane does the same? You can't, unless you're a god. And…
Afaik China for example is trying to actively manage the population growth/consumption problem, and sometimes they managed to introduce some environment friendly things that took other countries decades (like making filters in car exhausts mandatory, making plastic bags illegal, and so on). Not that China is a model of environmentalism, just saying that it's not a given that third world countries have to take the same route to modern living as US+Europe.
As for why would anybody save energy: it doesn't always have to equate less convenience. For example, even if you gave me the biggest possible car, with some magic CO2-neutral power source and what not, I would still not like commuting. So a solution that involves less commuting could both save energy and be more convenient (for example cool new houses could be build that make it more attractive to live in the city - in fact less cars would make living in the city a lot more attractive).
In general it seems to me that if "convenience X" involves a lot of energy, it will also involve a lot of nuisance (machines that make noises or need a lot of attention - lots of energy passing through it means likely it will break down sooner).
Or better insulating your house could simply be cheaper than paying for the energy to heat it - why wouldn't you then choose to insulate the house?
And so on.
