How Much is Energy Consumed Globally?

Each year, the equivalent of approx. 10 000 million tons of coal is consumed on earth as energy. About 40 % from this is based on oil and together with coal and natural gas more than 90 % of the total energy consumption result from carbon atoms in these fossil fuels. The consequence will be a global warming (greenhouse effect) and the lack of resources in the future. Today fossil fuels such as coal, oil and natural gas account for 90% of total primary energy supply. Estimated total world consumption of primary energy, in all forms (including non-commercial fuels like biomass), is approximately 400 EJ per year, equivalent of some 9500 million tonnes of oil (mtoe) per year.

The magnitude of energy problem that may face future generations can be illustrated by the simple calculation. The population of the world in 1990 was approximately 5 billion people. The UN estimates of population trends show it continuing to increase to around 8 billion by 2025, but stabilising towards the end of the next century at somewhere between 10 and 12 billion people. Most of that increase will be in the less developed countries. According to the US DOE (Department of energy) outlook for energy use throughout the world continues to show strong prospects for rising levels of consumption over the next two decades, led by growing demand for end-use energy in Asia. World energy demand in 2015 is projected to reach nearly 562 quadrillion British thermal units (Btu).

The expected increment in total energy demand between 1995 and 2015 - almost 200 quadrillion Btu - would match the total world energy consumption recorded in 1970, just before the energy crisis of 1973. Two-thirds of all energy growth will occur in developing economies and economies in transition, with much of that growth concentrated in Asia. Energy growth in the developing countries of Asia is projected to average 4.2 percent per year, compared with 1.3 percent for industrialized economies. The U.S. growth rate is expected to average only about 1 percent per year. As recently as 1990, U.S. energy consumption exceeded total consumption in the nations of developing Asia by 33 quadrillion Btu. By 2015, energy use in developing Asia is expected to exceed U.S. consumption by 48 quadrillion Btu.

According to the report of US DOE by 2015, oil use is expected to exceed 100 million barrels per day, a consumption rate 50 per cent greater than in 1995. Oil trading patterns are expected to shift markedly as oil consumption in Asia Pacific areas far outpaces domestic production gains, leading to a large increase in imports from Middle East suppliers. World-wide, coal use is projected to exceed 7.3 billion tons by 2015, compared with 5.1 billion tons in 1995. Growth in coal use will be regionally concentrated, occurring for the most part in India and China.

Natural gas is expected to have the highest growth rate among fossil fuels, at 3.1 percent a year, gaining share relative to oil and coal. By 2015 natural gas consumption on a Btu basis will exceed the total oil consumption recorded for 1995, at a level equivalent to two-thirds of the oil consumption projected for 2015. Natural gas consumption in 1995 was only about 55 percent of oil consumption. According to US DOE prediction only about 8 percent of projected growth in energy demand over the next two decades will be served by non-fossil fuel sources. In fact, the non-fossil (commercial) fuel share of world energy consumption declines from 15 percent to 12 percent over the projection period. Thus, world carbon emissions are likely to increase by 3.7 billion metric tons, or 61 percent, over the 1990 level by 2015. The Climate Change Convention of 1992 commits all signatories to search for and develop policies to moderate or stabilize carbon emissions. However, even if all the developed countries were able to achieve stabilization of their emissions relative to 1990 levels, overall world carbon emissions would still rise by 2.5 billion metric tons over the next two decades.

Per capita energy use in the world’s industrialized economies, which far exceeds the levels in newly emerging economies, is expected to change only moderately in the next two decades. In some emerging economies (for example, India and China), per capita energy use may double. Even with such growth, however, average per capita energy use in the developing countries will still be less than one-fifth the average for the industrialized countries in 2015.

In the longer term, consumption of oil as the principal source of commercial energy today, will start to decline after the transition phase (between 2020 and 2060). It is expected that natural gas will continue to be used as long as price and availability are satisfactory but as reserves reduce or prices rise coal (which is usually less expensive than natural gas and its international prices are unlikely to rise) will command a greater proportion of the market. To maintain energy levels and because of world-wide environmental concerns some experts predict that coal will have to be utilized cleanly, where gasification process will be the most environmentally friendly way of its future utilization.

The transition to a sustainable energy system requires that share of renewable energy sources will continually grow. Renewables combined with a system of new technologies, can contribute to a considerable extent to energy requirements in the time horizon beyond 2020. Report for the UN Solar Energy Group for Environment and Development suggests that using technology already on the market or at the advanced engineering testing stage, by the middle of the next century renewable energy sources could account for 60 percent of the world’s electricity market and 40 percent of the market for fuels used directly