"In terms of technology, there are a staggering amount of things in research stages that could help reduce consumption if they can be scaled up.
At the moment, we don't really have grid-level energy storage because the technology is not good enough to be worth it, but there are developments in things such as molten metal grid-storage batteries and supercapacitors which are improving. If a viable large scale energy storage solution is cracked, the biggest disadvantage of most renewable sources of energy is mitigated, which is that supply is intermittent and doesn't match demand at a given time. There are also smaller scale solutions being developed such as Tesla's PowerWall; large uptake of things such as this would smooth out energy demand throughout the day which would indirectly save energy too.
Then there are other developments which would reduce our energy consumption even more indirectly: Stem cell food could mature and end up eliminating industrial pastoral farming. Likewise, indoor vertical farming could replace industrial arable farming for suitable crops. These methods would likely be more efficient than the current intensive methods used today by itself, but since they could also be located in many more places it would greatly reduce the distance the produce would travel from farm to market. How much energy would we save if we no longer needed to ship most produce overseas?
All this is speculation and some, or all of these things may not come to pass.
Overall, I think technology has the greatest potential to reduce greenhouse gas emissions by developing processes that are more efficient than what we use now and in an end game scenario that's where most funding should be going.
That said, as mentioned earlier, investment really helps this process but in order for that to happen, a forward thinking electorate need to elect forward thinking people so education and engagement is also required.
Since technology and behavioural change are intertwined, it's hard to say which approach is more effective in isolation, especially as it's not a zero-sum game. Maybe we could solve the problem entirely by just throwing money at it, maybe someone is destined to figure out nuclear fusion and investment into renewables isn't worth it. Maybe it's already too late and we should instead invest in disaster response? I try not to think about it too much."
I think this is right. There are some amazing people out there with ideas for technologies that can make a big difference. But as several people pointed out, the answer isn't either technology or behaviour change, we need to work on all fronts to tackle this crisis (and it is a crisis).
Another post gives some hope on behaviour change, showing how some very bright people are working on the problem of planning major social change by supporting public programming in Scotland. Check out http://www.keepscotlandbeautiful.org/sustainability-climate-change/sustainable-scotland-network/low-carbon-behaviours/about-ism/ for more information. I'll finish by including the full post here:
"Jonny, up here in Scotland we are using a framework developed by the Scottish Government which looks at an integrated approach addressing Individual, Social and Materials aspects of change. Tech change and behaviour change are intertwined, and mediated through a social context. Analysis and action is needed that engages with the individual, social and material aspects of change - and most interventions tend to be weak in at least one area (usually the social aspects). You can find out more on our Sustainable Scotland Network website (www.sustainable-scotland.net) under the low carbon behaviours section. The ISM model simplifies a wide range of studies and provides a user friendly planning, implementation and evaluation tool. We also use work by Tim Kasser on values and frames. Having said all this, much still comes down to moral and political commitments and the ability to shift political and economic priorities."