Population Matters

Climate change

Climate change

The effects of global warming are already bringing harm to human communities and the natural world. Further temperature rises will have a devastating impact and more action on greenhouse gas emissions is urgently required.

Population and climate change are directly linked. Every additional person increases carbon emissions — the rich more than the poor — and increases the number of climate change victims – the poor more than the rich. Research shows that having smaller families and ending population growth are vital tools in the fight against climate change. 

The climate change threat

Further warming of our atmosphere is now almost impossible to avoid. The effects of that warming will depend on how high and how fast the temperature rises. Global warming changes weather patterns, causing severe weather events, heatwaves, droughts and floods.

Climate change is already shrinking glaciers and ice caps, altering the availability of fresh water. It contributes to ocean acidification, destroying coral reefs and other aquatic ecosystems. It makes places uninhabitable for some plants and animals, leading to extinctions and redistribution of species, threatening food production with alien pests and diseases.

Its potential human cost is catastrophic. A rise in sea levels threatens hundreds of millions of people in coastal communities and cities across the globe. Food and water shortages and conflict over productive land will arise, while progress in global health could be rolled back by communicable diseases such as malaria reaching places they never existed before.

Climate change action

The UN projects that without further action to limit population growth, there will be two billion more people by 2050, and three-and-a-half billion more by 2100.

Reducing the number of people being born cuts future carbon emissions – effectively, simply and permanently. While other measures are also essential – including technological solutions, personal lifestyle changes and policies to reduce fossil fuel use and develop alternative energy – the positive impact of each of those is reduced and may even be completely cancelled out by adding emissions from hundreds of millions of new people as our population increases.

Credit: Seth Wynes/Kimberly Nicholas, Environmental Research Letters, 2017

Individual actions

A key study published in 2017 by the Universities of Lund and British Columbia found that the single most effective measure an individual in the developed world can take to cut their carbon emissions is to have one fewer child. In fact, their research established that it was 25-times more effective than the next most effective measure, living without a car.

Global policy

Another major international study in 2017 identified practical policy measures that could be taken to minimise greenhouse gas emissions as quickly as possible. Project Drawdown analysed more than eighty policy options, such as plant-based diets, solar farms and electric vehicles.

Girls in classThe study identified family planning and educating girls as among the top 10 workable solutions to combat climate change available today. It found that together, they would reduce CO2 emissions by 120 gigatons by 2050 — more than onshore and offshore wind power combined.

Their enormous positive effect is a result of their proven effectiveness in reducing family size and population growth.

Population action

CO2 emissions comparison graphBecause individuals in the developed world have the greatest impact each, people choosing to have smaller families in the richest parts of the world will have the greatest and most immediate positive effect – a vital choice given the urgency to address which climate change. Furthermore, reduced emissions as a result of fewer people being born in richer countries allows more economic development in poorer countries without adding to total emissions.

However, in poorer countries, including those where population growth is highest, economic development is increasing individual carbon footprints and rapidly growing populations push emissions still higher. Nations with very high populations such as India and China are among the most significant contributors to climate change overall, despite relatively lower impacts from each individual. While India and China have relatively low population growth, people born today in countries whose populations are still expanding rapidly will have a climate impact for generations to come.

Reducing family size in all countries is needed to combat climate change.
Weapons in the war on climate change

There are many ethical, effective means of achieving this. In addition to family planning, girls’ education and other measures to empower women, education to inform people about the personal and global benefits of smaller families and action to challenge beliefs and values favouring large families can all help reduce family size and bring population growth to an end as soon as possible.

If we are to succeed in preventing the worst effects of climate change, we must take action to address population size.

Learn more about population solutions

Learn more about having a small family.

Read more about climate change.

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