According to the Intergovernmental Panel on Climate Change, human population growth is one of the two primary causes of increased greenhouse gas emissions and accelerating global climate change. Slowing or ending population growth could be a cost effective, environmentally advantageous means to mitigate climate change, providing important benefits to both human and natural communities. Yet population policy has attracted relatively little attention from ethicists, policy analysts, or policy makers dealing with this issue. In part, this is because addressing population matters (...) means wading into a host of contentious ethical issues, including family planning, abortion, and immigration. This article reviews the scientific literature regarding voluntary population control's potential contribution to climate change mitigation. It considers possible reasons for the failure of climate ethicists, analysts, and policy makers to adequately assess that contribution or implement policies that take advantage of it, with particular reference to the resistance to accepting limits to growth. It explores some of the ethical issues at stake, considering arguments for and against noncoercive population control and asking whether coercive population policies are ever morally justified. It also argues that three consensus positions in the climate ethics literature regarding acceptable levels of risk, unacceptable harms, and a putative right to economic development, necessarily imply support for voluntary population control. (shrink)

There is considerable confusion regarding the ethical appropriateness of using incentives in research with human subjects. Previous work on determining whether incentives are unethical considers them as a form of undue influence or coercive offer. We understand the ethical issue of undue influence as an issue, not of coercion, but of corruption of judgment. By doing so we find that, for the most part, the use of incentives to recruit and retain research subjects is innocuous. But there are some instances (...) where it is not. Specifically, incentives become problematic when conjoined with the following factors, singly or in combination with one another: where the subject is in a dependency relationship with the researcher, where the risks are particularly high, where the research is degrading, where the participant will only consent if the incentive is relatively large because the participant's aversion to the study is strong, and where the aversion is a principled one. The factors we have identified and the kinds of judgments they require differ substantially from those considered crucial in most previous discussions of the ethics of employing incentives in research with human subjects. (shrink)