Ah, there's someone still reading Slashdot who actually remembers this stuff, even used it. These young folks speak of the Zenith tuning fork remote as if it were a relic unearthed in an archaeological dig, and are as unaware of why we call it the "clicker" as they are wondering why we say "dial" the phone.
By 2050 disease and war will have reduced the global population to a fraction of what it is today, and whoever is left will not be wasting energy on heating and cooling McMansions and feeding oversized vehicles and toys. It won't be that we've managed to move to renewables on a scale that can keep up with the population, just that we've reduced the population to the point that renewable energy will have no problem keeping up with demand.
To invent, you need a good imagination and a pile of junk. -- Thomas Edison