Population control the solution to climate change
A week after the Royal Society published its musings on technological solutions that might curb climate change, another organisation has come up with what it believes is the cheapest and most effective way to tackle emissions - contraception.
A report from the London School of Economics commissioned by the trust claims that for every £4 spent on family planning over the next 40 years would cut carbon dioxide emissions by more than a tonne.
Achieving the same result with current low carbon technologies would, says the report, cost at least £19.
Fewer Emitters, Lower Emissions, Less Cost concludes that "considered purely as a method of reducing future CO2 emissions", family planning is more cost-effective than leading low-carbon technologies.
It does not advocate forced birth control, but does point out that UN figures suggest that 40% of pregnancies worldwide are not planned.
Roger Martin, chair of OPT, said the report highlights the need to include population in the broader climate change debate.
"It's always been obvious that total emissions depend on the number of emitters as well as their individual emissions - the carbon tonnage can't shoot down, as we want, while the population keeps shooting up," he said.
"The taboo on mentioning this fact has made the whole climate change debate so far somewhat unreal.
"Stabilising population levels has always been essential ecologically, and this study shows it's economically sensible too.
"The population issue must now be added into the negotiations for the Copenhagen climate change summit in December.
"This part of the solution is so easy, and so cheap, and would bring so many other social and economic benefits, from health and education to the empowerment of women.
"It would also ease all the other environmental problems we face - the rapid shrinkage of soil, fresh water, forests, fisheries, wildlife and oil reserves and the looming food crisis."