The shocking thing about climate change is how easy and inexpensive it could be to do a lot to reduce energy waste. Here are some really simple ideas - maybe you can add some suggestions in the comments.
Regulation that all buildings must publish a policy for inside temperature conditions and may not define a "dead-band" of less than 3C or 5.5F. A dead-band is the range where the temperature is deemed both hot enough and cold enough. Narrow dead-bands cause over-controlling (like a learner driver in a stick-shift car). In reality aiming to maintain a 0 Degree dead-band can (and often does waste a lot of energy) !
Require that all buildings that provide comfort or server-cooling publish the outside temperature at which they will rely on free cooling (i.e. ventilation with free cold air). Companies with silly policies could then be named and shamed (about 95% of office blocks in London are in this category).
In forced ventilation buildings ensure an interlock between fan-power and heating / cooling functions - If windows are opened building services are disabled !
Ask every energy manager in the world to write down a schedule of occupancy hours and post it on a public web-site. Until senior management agree it, or correct it - everyone can go home on full-pay. (Most energy managers are not given clear objectives).
Ensure that energy consumption for every public building is made publicly available, for criticism, comment and analysis.
Please add your answers below and have a look at what is happening in the US with the Green Button Initiative - We could do with some of that in Europe.