摘要：In their comment piece, van Basshuysen and Brandstedt raise three main issues: first, whether population at the global scale, or individual family planning decisions, are relevant for climate change mitigation; second, they offer useful critiques of the methodologies to attribute greenhouse gas emissions for the choice to have a child; and third, they question the appropriate ethical responsibility for emissions resulting from personal choices. Here we reply that first, we consider choices regarding family size to meet the authors' criteria for actions 'under the control of the individual agent and which, with a significant probability, contribute to' (increased greenhouse gas emissions), and therefore are relevant to consider for climate mitigation. Second, we acknowledge both methodological issues inherent in allocating responsibility for emissions, and encourage more research on this topic especially for the climate impact of reproductive choices. Third, we address ethical questions about responsibility for emissions, and conclude that while such discussions are important, and individual choices are only one part of necessary emissions reductions, people alive today are the last to have a chance at remaining within the carbon budget to meet international climate targets, and therefore do have a special responsibility to reduce emissions.
