Population and Global Warming

Some argue that while the burning of fossil fuels is the proximate cause of global warming, a growing population is the primary cause.

By 2050 there will be an estimated 9 billion of us on the planet, up from today’s 6.7 billion human beings. These extra bodies will require ever more environmental resources to satisfy their wants and needs.

Yet if current consumption levels continue unchanged, average global temperatures could eventually soar by 7.4 degrees Celsius by 2100.

To keep warming to a maximum of 2oC, total global emissions have to drop to about 0.3 tonnes of carbon per person by 2050, down from our current 1.3 tonnes each. This will require us to dramatically reduce consumption.

Currently, developing countries, with 85% of the world’s population, are responsible for 54% of total emissions, while the wealthiest 15% emitting about 46%.

However, since the industrial revolution, developed countries have cumulatively emitted 80% of human-produced greenhouse gases, and developing nations are responsible for a mere 20%.

On the face of it, the less people there are on Earth, the less greenhouse gas emissions we will collectively produce.

However, the devil is in the detail. The most rapid population growth is in developing countries, who contribute far less per person to greenhouse emissions than developed countries.

Conversely, most developed countries, with the highest per capita emissions, have very slow or even declining population growth.

Nevertheless, when today’s developing countries become increasingly industrialised, a large population will amplify total emissions enormously.

Significantly, population growth in developing countries will continue to contribute to rapidly increasing greenhouse gas emissions unless technical solutions to climate change can be cheaply employed in developing countries.

Yet technical solutions alone will not provide the wants and needs of a growing global population. Birth control, higher living standards and the empowerment of women are needed to reduce human numbers to sustainable levels.

Without a reduction in population, not only will global warming become increasingly intense, environmental refugees from overpopulated and climate-change affected areas will be displaced in their millions.


Kerri Smith, ‘The Population Problem’, Nature, 15 May 2008,

David Chandler, ‘Climate change odds much worse than thought’, MIT News Office, 19 May 2009, http://web.mit.edu/newsoffice/2009/roulette-0519.html

Richard Black, ‘Earth ‘heading for 6C’ of warming’, BBC News, 17 November 2009, http://news.bbc.co.uk/2/hi/8364926.stm

Ben Webster, ‘Developing nations outstrip rich on greenhouse gases’, The Australian, 18 November 2009, http://www.theaustralian.com.au/news/health-science/developing-nations-outstrip-rich-on-greenhouse-gases/story-e6frg8gf-1225799158422

Kerri Smith, ‘The Population Problem’, Nature, 15 May 2008, http://www.nature.com/climate/2008/0806/full/climate.2008.44.html