Slower population growth to help environment: UN study

Braking the rise in Earth's population would be a major help in the fight against global warming, according to an unprecedented UN report published on Wednesday that draws a link between demographic pressure and climate change.

Pedestrians cross a busy road in Sydney. Braking the rise in Earth's population would be a major help in the fight against global warming, according to an unprecedented UN report that draws a link between demographic pressure and climate change.

"Slower population growth... would help build social resilience to climate change's impacts and would contribute to a reduction of greenhouse-gas emissions in the future," the UN Population Fund (UNFPA) says.

Its 104-page document emphasises that population policies be driven by support for women, access to family planning, reproductive health and other voluntary measures.

"It really is the first time that a United Nations agency has looked hard at the connections between population and climate change," lead researcher Bob Engelman, vice president for programmes at the green group Worldwatch Institute, told AFP.

"People are at the root of the problem and at the solution of it, and empowerment of women is the key."

The report, the 2009 State of World Population, paints a grim tableau of the peril of climate change and the likely impact on humans, in terms of floods, drought, storms and homelessness.

But it notably puts distance between a decades-long tradition in the UN arena whereby population growth and its part in environmental destruction were rarely -- if ever -- evoked.

"Fear of appearing supportive of population control has until recently held back any mention of 'population' in the climate debate," the document admits.

Things, though, are starting to change. More than three dozen developing countries have already included population issues in national plans on climate, it says.

Negotiators, including the European Union (EU), have tentatively suggested that the question be considered in talks, designed to culminate in Copenhagen next month, for a 192-nation post-2012 global climate pact.

Today, the world's population stands at around 6.8 billion. By mid-century, it will range between 7.959 billion to 10.461 billion, with a mid-estimate of 9.15 billion, according to UN calculations.

The difference between eight billion and nine billion is between one and two billion tonnes of carbon per year, according to research cited in the report.

That would be comparable to savings in emissions by 2050 if all new buildings were constructed to the highest energy-efficiency standards and if two million one-gigawatt wind turbines were built to replace today's coal-fired power plants.

"[P]opulation growth is among the factors influencing total emissions in industrialised as well as developing countries," it says.

"Each person in a population will consume food and require housing, and ideally most will take advantage of transportation, which consumes energy, and may use fuel to heat homes and have access to electricity."

Mitigating population rise would have a double benefit, it says.

It firstly reduces greenhouse-gas output, especially if the decline occurs in developed countries, whose per-capita emissions are up to 10 times those of poor countries.

And it also helps countries -- especially poor nations with high population growth -- adapt to the impacts of climate change.

"The growth of population can contribute to freshwater scarcity or degradation of cropland, which may in turn exacerbate the impacts of climate change," says the report. "So too can climate change make it more difficult for governments to alleviate poverty and achieve the Millennium Development Goals."

The report says taking demographics into account can help national policies and the quest for a UN climate agreement.

Women are not only more vulnerable than men to the effects of climate change but also hold the key to helping resolve it through fertility control and involvement in the economy, it adds.

Thus helping women will entail access to reproductive health care, education and gender equality.