A new study produced by the London School of Economics found that family planning is the most cost effective way to address CO2 emissions. As reported over at WorldChanging by Adam Stein,
"Specifically, the report claims that the world can spare 34 gigatons of CO2 emissions — the amount the entire U.S. produces in six years — over the next four decades at a cost of $7 per ton. According to the report, these reductions can be achieved simply by fulfilling the current “unmet need” for family planning, an ungainly phrase that refers to the population of couples who are married or “in union” and want contraception but lack access. Because unmarried people experience unwanted pregnancy as well, presumably demand for contraception is even greater than the study suggests.
If all this unmet need is filled, the projected population in 2050 drops from 9.1 billion to 8.7 billion. 8.7 billion, of course, still represents substantial growth from today’s level. That’s always been the problem with focusing overly much on population as the key driver of climate change: the number of people on the planet seems likely to hit roughly 9 billion no matter what we do, so ultimately clean energy and efficiency are going to be the primary way we solve the resource puzzle.
Nevertheless, 34 gigatons is a lot of gas, and $7 is a nice price, and providing family planning services to people who want them has meaningful humanitarian benefits, so this seems like a fruitful (ha!) area to explore. Of course, family planning is also an insanely fraught topic, so don’t expect much progress on this front anytime soon, at least in the U.S."