general assumptions
projection of population development
Following the IEA’s reference scenario, which uses United Nations population development projections, the world’s population will increase from 6.3 billion people now to 8.9 billion in 2050.This continuing growth will put additional pressure on energy resources and the environment.

development of global energy demand
Combining the projections on population development, GDP growth and energy intensity results in future development pathways for the world’s energy demand.These are shown in Figure 17 for both the reference and the energy [r]evolution scenarios. Under the reference scenario, total energy demand almost doubles from the current 310,000 PJ/a to 550,000 PJ/a in 2050. In the energy [r]evolution scenario, a much smaller 14% increase on current consumption is expected by 2050, reaching 350,000 PJ/a. An accelerated increase in energy efficiency, which is a crucial prerequisite for achieving a sufficiently large share of renewable sources in energy supply, will be beneficial not only for the environment but from an economic point of view. Taking into account the full life cycle, in most cases the implementation of energy efficiency measures saves money compared to increasing energy supply. A dedicated energy efficiency strategy therefore helps to compensate in part for the additional costs required during the market introduction phase of renewable energy sources.

