To maintain economic wealth (roads, hospitals, power
lines, etc.) power needs to be consumed. The same applies to economic activity,
since any activity requires the consumption of energy. According to the Environmental Protection Agency, the burning
of fossil fuels was responsible for 79 percent of U.S. greenhouse gas emissions
in 2010. So whilst economic
activity takes place fossil fuels will be burned and CO2 emissions are
unavoidable - unless we use exclusively renewable energy resources, which is
not likely to occur very soon. However, the increasing CO2 concentrations in
the atmosphere will have negative consequences, such droughts, floods, crop
failures, etc. These effects represent limits to economic growth. The CLD
illustrates some of the more prominent negative feedback loops that act as a
break on economic growth and wealth. As the negative feedback loops (B1-B4) get stronger, an interesting question is, 'will a sharp reduction
in economic wealth and unavoidable recession lead to wide-spread food riots and disturbances?'