"You might think that cutting population growth is most important in places like Africa, where birthrates are higher than anywhere else in the world. ...But in fact, it's curbing population in rich, developed countries that has the biggest influence on climate change."

-- Laurie Goering, Thomson Reuters Foundation Climate editor/ Head of Climate Programme

Every week, our correspondents offer distilled insight on pressing issues. Two-Minute Talking Points bring you concise commentary from the frontlines of humanitarian crises, climate change, corruption and human rights.

Transcript:

In the things we do each day, each of us are changing the world's climate. We cook meals, travel, build homes, heat them, turn on the lights when the sun goes down.

The problem is that as there are more and more of us, we are changing the climate faster and faster. The world 's population has more than doubled in the last 50 years, from just over 3 billion people to just over 7 billion. By 2050, the UN predicts it will hit 9 billion.

The cheapest and most effective way to curb climate change, most experts agree, is to get contraceptive services to the more than 220 million women around the world who want them but can't currently access them. Experts say the cost of doing that would be about $4 billion -- a tiny fraction of the cost of damage from climate-linked storms, which now runs into hundreds of billions of dollars around the world each year.

You might think that cutting population growth is most important in places like Africa, where birthrates are higher than anywhere else in the world. The average women in Nigeria, for instance, still will have about five children in her lifetime. In the United States, the average is now just two children.

But in fact, it's curbing population in rich, developed countries that has the biggest influence on climate change.

An average American produces about 17 tonnes of carbon dioxide a year. The average Nigerian produces a little over half a tonne. That means that each additional child born in America will produce 28 times as many climate-changing emissions each year as a child born in Nigeria.

Many Nigerians aspire to the same lifestyle as Americans, and emissions there may not stay low -- look at countries like India and China, whose emissions are rising along with their incomes.

But the rich should think before dismissing population growth as simply a problem of the poor. When it comes to curbing climate change, rich families may need to begin acting a little more like Nigerians -- not by having bigger families but by reducing the resources they use and the emissions they produce.