• reproductive health politics
• health education
• family planning service provision
• epidemiology
• counselling

I read with interest the commentary article by Bongaarts and Sitruk-Ware.1 I think this commentary is very timely, and I am so glad to see this topic being discussed. However, I wondered whether there could have been more of a focus on the impact of population in developed countries, particularly on the impact of having a child if you are in the most socioeconomically developed subgroup of the population? I would be really interested to hear the commentary authors' views on this.

Although the unintended pregnancy rate is much higher in developing countries than in developed countries,2 the impact on the climate for a child in a developed country is much greater than in a developing country.3 The richest 10% of the world’s population are responsible for almost half the total lifestyle consumption emissions and the poorest 50% responsible for only 10% of emissions.3 I appreciate that increasing industrialisation and rapid population growth in developing countries is likely to be a problem in the future, and that emissions from high-income countries (which are much higher in absolute and per capita terms) are expected to level off or decline as populations stabilise or decline and carbon emissions per capita decline.4 However, the reality is that the most developed countries are currently responsible for the majority of worldwide carbon emissions and that net zero emissions targets are unlikely to be realised with the current governments in developed nations. Carbon emissions per capita in the UK and the US are currently more than 80 and 150 times, respectively, those of in many sub-Saharan African countries.5

The impact of one less unintended birth in a developed country is likely to be much greater than the impact of a birth in a developing country and substantially greater for the richest 10%.3 The comment in the Lancet article that "the unintended birth rate is not currently declining in developed countries" is therefore important.2The focus of urgency should therefore be on both populations alongside global policies to curb emissions per capita. Empowering women in both developed and developing countries to be able to make contraceptive choices and become pregnant when the time is right for them could have an impact on global emissions in the long term.

I wonder whether appropriate and timely counselling for women on contraception choices in developed countries could have an even greater impact on climate change in the immediate future?