Looking through clippings from 2009:

Can Condoms help fight climate change?  Yes, and they should, wrote an editorial  of  medical journal Lancet!

In addition to boosting the health, standard of living and human rights of women, encouraging the use of contraception also will help save the planet. The calculus is simple: preventing unwanted pregnancies — especially in the developing world — translates into reduced demand for increasingly scarce and energy-intensive resources like food, water and shelter.

More than 200 million women around the world would like access to modern contraception, and their lack of it leads to 76 million unintended pregnancies each year, according to Lancet.

Thomas Wire, a postgraduate student at the London School of Economics, came to essentially the same conclusion. In a report titled “Fewer Emitters, Lower Emissions, Less Cost,” Wire calculated that if present trends continue, the planet is on track to have 338 billion “people-years” lived between 2020 and 2050. But if contraception were available to every woman who wanted it, so many pregnancies would be averted that the number of people-years would fall to 326 billion.

That reduction of 12 billion people-years would save 34 gigatons of carbon dioxide that would otherwise cost at least $220 billion to produce. In other words, each $7 invested in contraception would buy more than 1 ton of carbon dioxide emissions.

Among the first 40 developing countries to submit global warming adaptation plans to the U.N.  Framework Convention on Climate Change, 37 linked population growth to global warming. But only six of those countries incorporated contraception into their plans, according to Lancet. That should change, the editorial says.

and from a second source: “The world’s population is expected to reach more than 9 billion people by 2050, with 95 percent of this growth in developing countries. Those in support of investing in reproductive health services and contraception to combat climate change argue that having fewer children means less carbon emissions and less strain on diminishing natural resources.

An editorial in the medical journal Lancet last month called attention to the links between rapid population growth and increased vulnerability to the consequences of climate change, such as food and water scarcity and environmental degradation. It suggested that by reducing unintended pregnancies, we could slow the high rates of population growth and possibly ease pressure on the environment. The Lancet says that over 200 million women want, but currently lack, access to modern contraceptives, resulting in 76 million unintended pregnancies every year.

An economic case was made for investing in reproductive health by a recent study from the London School of Economics (LSE) and commissioned by the UK-based Optimum Population Trust. It showed that contraception is almost five times cheaper than leading green technologies, such as wind and solar power and hybrid or electric cars, to combat climate change. Specifically, the study found that each $7 (£4) spent on basic family planning over the next four decades would reduce global carbon dioxide emissions by more than a ton, but it would cost a minimum of $32 (£19) to achieve the same result with low-carbon technologies.”