The implications of population growth and urbanization for climate change

Abstract

This paper considers the implications of population growth and urbanization for climate change. It emphasizes that it is not the growth in (urban or rural) populations that drives the growth in greenhouse gas (GHG) emissions but rather, the growth in consumers and in their levels of consumption. A significant proportion of the world’s urban (and rural) populations have consumption levels that are so low that they contribute little or nothing to such emissions. If the lifetime contribution to GHG emissions of a person added to the world’s population varies by a factor of more than 1,000 depending on the circumstances into which they are born and their life choices, it is misleading to see population growth as the driver of climate change. A review of carbon dioxide (CO2) emissions levels for nations, and how they changed between 1980 and 2005 (and also between 1950 and 1980), shows little association between nations with rapid population growth and nations with high GHG emissions and rapid GHG emissions growth; indeed, it is mostly nations with very low emissions per person (and often only slowly growing emissions) that have had the highest population growth rates. The paper also discusses how in the much-needed planning for global emissions reduction, provision must be made to allow low-income, low-consumption households with GHG emissions per person below the global “fair share” level to increase their consumption.