Population and climate change

Posted: 30 March 2009

As population continues growing, so do greenhouse gas emissions. It is a major factor in climate change, yet it receives little attention. Overpopulation is also a grave concern because not all of the Earth's sources are renewable or remain renewable under greater stress.

  • Between 1950 and 2007, world's population grew from 2.5 billion to 6.9 billion. Half of the world's population is expected to be living in urban environments by 2010, and by 2025, the population is projected to increase by an additional 2.7 billion to reach 8 billion.

  • Industrialized countries have produced the bulk of greenhouse gas emissions to date: The United States alone accounted for an estimated 19 per cent of total world carbon emissions in 2007.

  • US emissions per capita of carbon dioxide in 2007 stood at 19.2 metric tons of carbon dioxide, while for Japan and the European Union (EU-27), the figures were 9.7 and 7.6 metric tons of carbon dioxide, respectively.

  • Emissions per capita in India increased from 0.8 metric tons in 1990 to 1.2 metric tons in 2007. The population in India grew from 860 million in 1990 to 1.2 billion in 2007.

  • In China - the most populous country in the world - emissions of carbon dioxide have more than doubled from 2.0 to 4.4 metric tons per capita between 1990 and 2007, while the population increased from 1.15 billion to 1.36 billion. And it is estimated that in 2007, China accounted for 21 per cent of the world's total emissions, surpassing the United States for the first time. In contrast, the population in the United States increased from 256 million in 1990 to 315 million in 2007.

  • Most rapidly growing populations currently have very low per capita greenhouse gas emissions, but per capita emissions and populations are increasing rapidly in much of the world, and the developing world is becoming a substantial contributor to climate change.

  • Population growth also increases the number of people who will be affected by climate change, though it remains unclear how specific communities will be affected.

Related links:UN Population FundPopulation Action International: Population and Climate ChangeDavid Satterthwaite and David Dodman, The Role of Cities and Climate, in State of the World 2009: Into A Warming World, (Washington, D.C.: Worldwatch Institute), 2009.