In their Policy Forum “Global warming policy: Is population left out in the cold?” (17 August, p. 650), J. Bongaarts and B. C. O'Neill explore why climate groups such as the Intergovernmental Panel on Climate Change (IPCC) have overlooked the role of population growth. Authors of a recent IPCC report responded that population growth was addressed in their chapter but excluded from the summary for policy-makers. An excerpt of their comment is shown below. Read the full eLetter and add your own at . “…[T]he Policy Forum deplores the failure to explicitly include population issues in IPCC summaries.…Population issues, however, were in fact discussed in the Fifth Assessment.…Chapter 11.9.2 [[www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap11_FINAL.pdf][1]] specifically [notes] that providing greater access to reproductive health services for those who wish to limit their families will both…mitigate climate-relevant pollutants and protect human health. Unfortunately, this information was not included in the final WGII Summary to Policy-Makers or IPCC Synthesis Report.…Indeed, there are a wide range of issues raised in the assessment chapters that never see the ‘light of day’ in the summaries…[We] should focus…on developing rigorous and transparent guidance on how decisions are made on what, from a vast panorama of analyses in the main chapters, is highlighted for policy attention.…” [1]: http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap11_FINAL.pdf