"Humans are smarter than other animals, allowing the population of humans to grow, while the population of many other species tends to fall. […] The large rise in the population of the less advanced economies contributes to the huge number of immigrants wanting new homes in higher-income countries. […] The issue is that available resources do not rise fast enough (in the area, or with the technology available) to provide enough physical goods and services for the population. If a new approach can be developed, or a neighboring area with additional resources can be conquered, [the] population can start to grow again. […] Outgrowing our resource base is not a phenomenon that began with fossil fuels. […] In 1796, when [the] world population was about one billion, Robert Thomas Malthus wrote about population growing faster than food production. This was before fossil fuels were widely used. Now, about 230 years later, [the] population has risen to eight billion, thanks to the availability of fossil fuels. We need major innovations, or additional energy resource types, if we want to work around obstacles now."