Human well-being is a direct function of power consumed, or the rate at which work is done. The relationship between rate of energy consumption and rate of wealth production should not surprise anyone. The faster work is done (more power consumed), the more wealth that is produced. It is impossible to think of a single wealth-producing activity that does not require work—the expenditure of energy. The great increase in the world’s wealth since the Industrial Revolution is the obvious outcome of using fossil fuels to provide the energy for machines to do work. We got rich in the last couple of centuries in large measure because we used so much fossil energy. If we are not able to maintain high-energy consumption rates, the data summarized below strongly suggest that we will get poorer, sicker and less educated.
About 93% of the variation in per capita wealth production (GDP per capita) between different countries can be explained simply by how fast they use energy—the power they consume—as seen in Figure 1.
A broader measure of human well being than just wealth includes the Human Development Index (HDI), a composite measure of expected life span, expected years of schooling and wealth. Figure 2 shows that HDI rises rapidly with increased power consumption and levels off at about 2-4 kilowatts (kW) per capita. Apparently we need about 2-4 kW per capita to achieve good levels of health, education and wealth.
The numbers are sobering. If everyone on the planet were to consume 2 kW of power, we would need about 14 terawatts overall…roughly the current world power use. If everyone were to obtain a more comfortable life using 4 kW instead of 2 kW, the total world power consumption would need to double. Where would that energy come from? Approximately 85% of current world energy use is from fossil fuels: coal, oil and natural gas. These are non-renewable resources. When they are exhausted, the wealth they produce will likewise disappear.
Peak (cheap) oil arrived in 2005. Peak coal and peak natural gas are yet to come, but they will come simply because they are not renewable. Peaking and decline of non-renewable resources is not a matter of politics or economics or philosophy, it is a matter of physics and geology. Thus very large-scale renewable energy systems are not just a “good idea”; they are essential. If we do not implement large-scale renewable energy systems now, we can count on being poorer, much poorer, in the future.