Population and Climate Change
There are clear indications that growth in human population plays an important role in the process of climate change.
However there is a need for the linkage to be clearly identified and proven, to the satisfaction of scientific, political and media opinion.
The problem lies in that the population-environment nexus is inherently multidisciplinary, which makes it more difficult to advance theories or conduct empirical research that is accepted as valid.
Proving these links could not only make a significant contribution towards effectively addressing a key dimension of climate change, but at the same time substantially enhance the policy and budgetary profile of the population factor, producing wider benefits in other areas.
The greatest proportion of greenhouse gas emissions is currently caused by the developed world, where only around 5% of predicted population increase over the next 45 years will occur.
However, the following aspects suggest substantial correlation between global population increase and climate change:
Direct Relationship
- A median forecast projected growth of 2,500 million in the population of the developing world by 2050 will give rise to a very substantial increase in greenhouse gas emissions. “Population growth rates will be higher among the developing countries, which are also likely in aggregate to have more rapid emissions growth per head. This means that emissions in the developing world will grow significantly faster than in the developed world, requiring a still sharper focus on emissions abatement in the larger economies like China, India and Brazil.” Stern Report P183
- Whilst developing country emission levels per capita are currently far lower than in the developed world (eg China 4 tons per capita and India 1 ton, against the EU 10 tons, USA 20 tons) , this increase will be further augmented as these countries achieve higher per capita living standards as a rightful and necessary aspiration for their citizens.
- The economies of developing countries are generally more dependent on carbon-based energy sources, and lack the resources to invest in emission controls, renewable energies or other forms of solution.
Indirect Relationship
As it is characterized by high fertility, in many of the world's poorest countries high population growth often also compounds environmental, social and human vulnerability to the effects of climate change.
“Changes in the climate will amplify the existing challenges posed by ….. rapid population growth”. “Developing economies are very sensitive to the direct impacts of climate change given their heavy dependence on agriculture and ecosystems”. Stern Review P92 and P95
- Even without climate change, population growth by itself may result in several billion more people living in areas of more limited water availability. Around one-third of today’s global population live in countries experiencing moderate to high water stress, and 1.1 billion people lack access to safe water. Stern Review P 63
- The impacts of climate change, coupled with population growth in developing countries, will exert significant pressure for cross-border and internal population movement. There is already evidence of the pressure that an adverse climate can impose for migration. Stern Review P 111
- The effects of climate change - particularly when coupled with rapid population growth and existing economic, political, ethnic or religious tensions - could be a contributory factor in both national and cross-border conflicts in some developing countries. Stern Review p 112