Population and climate change

• Between 1950 and 2000, world�s population grew from 2.5 billion to 6.1 billion. By 2050, population is predicted to increase by a further 2.8 billion to 8.9 billion. Just as past population increase has influenced the composition of the earth�s atmosphere in the late 20th century, the rate of future increase will influence the earth�s climate for centuries to come.
  

• Industrialized countries have produced the bulk of greenhouse gas emissions to date: The United States alone accounted for 23 per cent of total world CO2 emissions in 2002. In that year, US per capita emissions of carbon dioxide stood at 19.7 metric tons, while for Germany and Japan the figures were 10.2 and 9.5 metric tons, respectively. The EU-15 produced 8.4 tonnes average emissions. In contrast, the global average for that year was 3.9 metric tons per capita. For India, it was 1.0 metric tons.
  

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

• In China, emissions of carbon dioxide rose from 1.5 to 2.6 metric tons per capita between 1980 and 2002, while the population increased from 984 million to 1.3 billion. As a result, China accounted for 13.5 per cent of the world's total emissions in 2002, second only to the United States. India ranked sixth, after the EU-15, Russia and Japan.
  

• Future climate change agreements are likely reflect the view that people of the world enjoy equal rights to use the atmosphere to dispose of the carbon generated by fossil fuel combustion. Such a principle would make the overall size of the human population a critical variable. The larger the population becomes, the lower the average per capita level of emissions commensurate with acceptable levels of greenhouse gas production. In other words, as population grows, each individual's right to pollute shrinks.
  

• 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. In addition to rising temperatures and changing weather patterns, a number of less obvious effects could occur. Agricultural productivity might be boosted in some areas, but disrupted in others, worsening malnutrition. Global warming could also lead to a redistribution of disease-carrying insects.

Related links:

The Effect of Population on Global Climate Change (Committee for the National Institute for the Environment, Washington DC).

Profiles in Carbon: an update on population, consumption and carbon dioxide emissions, published by Population Action International, Washington DC.

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