Natural resources, including minerals, water, energy and arable land, are the basis of human society. Throughout the 20th century, the growing population has led to an increase in the use of fossil fuels by a factor of 12, and to the extraction of 34 times more material resources. As a consequence, Earth’s climate is changing, fish stocks and forests are shrinking, the prices of energy resources and critical materials are rising, and species are becoming extinct. If the population grows as expected and the mean per capita consumption doubles by the year 2050, it is most probable that humanity will experience the limits to growth.