World Population, Economic Growth, and Energy Demand, 1990-2100: A Review of Projections

Abstract

This article assesses world population energy consumption economic productivity and carbon dioxide emissions and concentration estimated projections generated by the World Energy Council (WEC). The UN medium variant of population projection (8092 million) is plausible for the period up to 2020. Plausible energy consumption in 2020 is identified as the WEC Case B or 13.4 gigajoules of metric ton of oil equivalent (Gtoe) and supplementary Case D or 11.0 Gtoe. Current 1990 usage is 8.8 Gtoe. The projection of energy consumption for the year 2100 is not expected to exceed 20 Gtoe which is the equivalent of the global average of 1.7 tons of oil per capita. Usage would increase by 50% over 1990 fossil fuel production in combination with a doubling of traditional biomass production a quadrupling of hydroelectricity production a 9-fold increase in nuclear energy production and a 12-fold increase in new renewable energy production. Carbon dioxide (CO2) emissions are likely to be higher than the 355 parts per million by volume (ppm) in 1990 but somewhat lower than Case B figures of 617 ppm and higher than Case C figures of 469 ppm. Unfavorable climatic conditions resulting from increased CO2 concentrations are part of the price to be paid for fossil use in an affluent society. The calculation of energy demand is based on an assumed rate of economic growth and an assumed rate of decline in energy intensity. Economic growth rates in developing countries are assumed to exceed those in developed countries and gross domestic product (GDP) will be negatively associated with population growth. GDP growth in more developed countries is expected to be 2.4%. Case A in less developed countries assumes a high variant of 5.6% for GDP growth. Case B and C assume 4.6% growth. Three GDP and 3 population growth rates were combined to yield 9 rates for each country grouping. Cases D and E assume lower growth. Cases A and B assume higher energy demand.