The direct fuel scenario

In the global energy demand scenario, the use of fuels for purposes other than electricity generation will grow by less than one-third, much less than the generation of electricity. Table 3 shows the direct fuel scenarios [29].

The renewable contribution to fuels used directly could reach nearly one-quarter by 2025 and two-fifths by 2050, with most of the contribution coming from biomass-derived fuels such as methanol, ethanol, hydrogen, and biogas. Methanol and biogas may well prove to be the biofuels of choice because they are the energy carriers most easily used in the fuel cells that would be used for transportation.

Table 3 also shows the levels of CO2 emissions that the scenarios described will produce. Global CO2 emissions from the burning of fossil fuels associated with the renewables-intensive scenario would be reduced 12% by 2025 and 26% by 2050. During this period, the CO2 emissions from industrialised countries would be nearly halved by 2025 and down to a third of present values by 2050. The industrialised countries share of total worldwide emissions would decline from about three-quarters in 1990, to about two-fifths in 2025 and one-third in 2050.

Global CO2 emissions per capita would be halved by 2025 and reduced to less than two-fifths of present values by 2050. Despite the rising relative contribution of developing countries to the total global CO2 emissions, per capita emissions of developing countries in 2050 would still be only one-third of those for industrialised countries.