The argument about computing power and CO2 pollution is misguided. HTTP/2 no longer requires encryption, so the TLS/non-TLS trade-offs remain the same as before (and their compute impact is mitigated by hardware AES support, etc.). The other relevant changes (SPDY, header compression, push) reduce the number of context switches and network round-trips required and the total time required for devices to spend in high power mode, and for the user to spend waiting. That results in a reduction, not increase, in total power consumption.

Taking server CPU utilization numbers as an indicator of total power consumption is pretty misguided in this context, and my understanding is that even those are optimized (and will continue to be optimized) to the point where TLS and SPDY have negligible overhead (or, in the case of SPDY, may even result in lower CPU usage).