There are two primary driving forces for the increased demand of energy with the world:
- the increase in the human population.
- the increase in the standard of living across the world.
However the world primary energy consumption has increased by about 2% per anum or doubled every 36 years. This rate reflects the speed at which we can bring energy into the economy. Nicholas Georgescu Roegen has argued that an economy in choosing to spend its energy to make tractors does so at the expense of using it to build factories. Thus we make a choice not only of what we can have in the economy but how the economy will grow. Many including Malcolm Slesser have shown that energy is the primary limiting factor for sustainable development of an economy.
From 1970 when we consumed about 215 Quadrillion Btu in 2006 we were consuming an estimated 464 Quadrillion Btu. If we were to continue to deliver energy at 2% per anum, an additional 215 Quadrillion Btu or 679 Btu will be used by 2021!
Currently fossil fuels, particularly oil, contribute a major share of the world's energy supply. The global oil production is expected to peak by 2020. The key questions that need urgent attention to create a sustainable energy consumption are:
- How much time do we have before we are unable to meet the economy's energy needs? We may be unable to meet the need because meeting it would destroy our environment or we have simply unable to substitute other energy sources to replace fossil fuels fast enough. Remember switching to an alternate energy system has an energy cost too. It takes energy to build solar panel factories and produce them. It takes energy to decommission existing energy systems and replace them with new ones.
- How long does it take our current global and local systems to respond to meet these needs?
So if we have say 10 years, say, before our energy systems break down or cannot deliver the economy's need (locally this can be sooner or longer) and it takes our systems (governments, utilities, businesses and citizens) more than 10 years to respond with a cope strategy we are on an unsustainable trajectory. Especially if one accepts that the breakdown of energy security is also a breakdown of economic security.