Human population growth and climate change

I've been troubled by the issue of population growth in the recent IPCCC report I've been reading. So as I slog through the more than 1,100 pages, I decided to take the quick route and Google it.

This is what I found on the Population and Sustainability Network webpage:

What does the IPCC report say about population dynamics and climate change?

April 11, 2014

SOURCE: PSN

The latest IPCC report identifies changes in population as factors that exacerbate climate change vulnerability. Here we present the report’s key messages about different population dynamics and access to reproductive health etc.

Credit: UN Photo/Nasim Fekrat

The report known as the second volume of the Fifth Assessment Report, released by the UN’s Intergovernmental Panel on Climate Change (IPCC) noted that “human interference with the climate system is occurring, and climate change poses risks for human and natural systems”.

These are the report’s key references to population, with direct quotes from the report:

Freshwater resources

• Non-climatic drivers such as population increase, economic development, urbanisation, and land-use or natural geomorphic changes also challenge the sustainability of resources by decreasing water supply or increasing demand.

• Over the next few decades and for increases in global mean temperature of less than around 2oC above pre-industrial, changes in population will generally have a greater effect on changes in resource availability than will climate change. Climate change would, however, regionally exacerbate or offset the effects of population pressures.

Coastal systems and low-lying areas

• The population and assets projected to be exposed to coastal risks as well as human pressures on coastal ecosystems will increase significantly in the coming decades due to population growth, economic development, and urbanisation. 

• All the studies indicate high and growing exposure of low-lying coastal areas. The Low Elevation Coastal Zone (LECZ) constitutes 2% of the world’s land area but contains 10% of world’s population (600 million) and 13% of world’s urban population (360 million) based on year 2000 estimates.

• About 65% of the world’s cities with populations of over 5 million are located in the LECZ. 

• The population living in coastal lowlands is increasing and more than 270 million people in 2010 are already exposed to flooding by the 1-in-100 year coastal flood. Population growth and land subsidence in coastal lowlands are the major causes; therefore there is very low attribution to climate change.

Food security and food production systems

• Developing countries rely heavily on climate -dependent agriculture and especially in conjunction with poverty and rapid increase in population they are vulnerable to climate change. While food insecurity is concentrated mostly in developing countries situated in the tropics global food supply may also be affected by heat stress in both temperate and subtropical regions.

Human health and the role of family planning

• Although population growth rates and total population size do not alone determine emissions, population size is an important factor. One study showed that CO2 emissions could be lower by 30% by 2100 if access to contraception was provided to those women expressing a need for it. Providing the unmet need for contraceptive services in areas such as the Sahel region of Africa that has both high fertility and high vulnerability to climate change can potentially significantly reduce human suffering as climate change proceeds. This is important not only in poor countries, however, but also some rich ones like the US, where there is unmet need for reproductive health services as well as high CO 2 emissions per capita.
• Slowing population growth through lowering fertility, as might be achieved by increasing access to family planning, has been associated with improved maternal and child health – the co - benefit - in two main ways: increased birth spacing and reducing births by very young and old mothers.    
• Programs to provide access to reproductive health services for all women will not only lead to slower population growth and its associated energy demands, but also will reduce the numbers of child and maternal deaths. 

Key economic sectors and services

• For most economic sectors, the impacts of drivers such as changes in population, age structure, income, technology, relative prices, lifestyle, regulation, and governance are projected to be large relative to the impacts of climate change.

Human security

• Climate change over the 21st century is projected to increase displacement of people.
• Displacement risk increases when populations that lack the resources for planned migration experience higher exposure to extreme weather events, in both rural and urban areas, particularly in developing countries with low income.

Read more about the fifth volume of the IPCC report. 

Taken directly from:
http://populationandsustainability.org/what-does-the-ipcc-report-say-about-population-dynamics-and-climate-change-html/