The difference between an acoustic gig and an electric one is extremely marginal and comes down to the amount of electricity used by the instruments. All other inputs would be the same; the running of the club; getting the punters there; the drinks input. In fact it might be possible to show that because the acoustic gig is smaller than an electric one the larger audience to crew ratio of an electric gig might make it more efficient!
There is a slight reduction in GDP to energy use over time but the efficiencies suffer from the law of diminishing returns over time. Technology which improves with time still uses energy; it doesn't save it. Productivity replaces human labour with technological input and hence greater energy use.
It could be said that productivity is the enemy of climate change as it means more energy use and we have to find more work for humans to do to make up of the productivity job losses and hence use even more energy and resources.
The GDP increase since 1800 has been 90% fuel/energy driven. And green energy doesn't exist in sufficient quantities to produce no change in GDP. To give an idea of our reliance of fossil fuel energy, the average human lives with the fossil fuel energy equivalent of 200 human slaves working for them while in the west the average energy use is equivalent to 500 to 1000 human slaves.
In 1800 the average farm worker produced enough food for 1.5 people so when we reduce our energy use in farming we will require a massive migration of people back to the land. In the UK we only just have enough land, according to the
third Zero Carbon Britain report from CAT, to feed and provide energy for our current population and some space for wildlife. Any increase in population takes land away from the little wildlife that we have left.
Oil consumption in Europe overall has dropped by 18% since 2006 and gas supply is down 22%. Individual output has been dropping since 2005 except in Germany, where it is the same, and in the US where an increase has been fuelled by shale oil and gas. How much of that output increase is purely the energy going into getting the shale gas and oil out, Mr Jancovici didn't say but given the much lower EROEI of shale products a fair proportion of the increased output would have been within the industry itself.
This is another of the problems we face; the decrease in EROEI of our energy sources. A much greater proportion of our energy and investment goes into producing energy, especially with renewable energy. It might not cost anything to run renewables but the EROEI is much lower than conventional oil, gas and coal. This point is made very well in Energy and the Wealth of Nations: Understanding the Biophysical Economy by Charles A. S. Hall, Kent A. Klitgaard (ISBN: 0001441993975) One of their major points is that there will be a shortage of available investment to fuel the change over from fossil to renewable energy. This point is also alluded to in the Hirsch Report when they say that it would take 30 years to transition from the current economic system to a renewable one.
Getting back to my original point of a few posts ago, we have to start mitigating against sea level rise very quickly as, added to the other costs we will face of replacing the massive loss of capital and infrastructure to rising waters, we will be hard put to cope with our current population let alone one increased by millions, possibly tens of millions, of refugees. Added to this will be the problem of climate change interfering with the agricultural production on what will be overall much smaller area of much poorer farm land.