Evidence for anthropogenic climate change continues to build, but even some academics retain a skeptical attitude toward the radical claim that humans are significantly changing the climate of Earth. In a recent article published in Science and Engineering Ethics, on which I am co-author, we discuss several issues raised by climate change skeptics.

The first issue we address is an observed decline in global temperature from 1943 to 1975, which resulted from an increase in emission of sulfur aerosol from industrialization that scattered away sunlight and cooled the surface. The second issue is the use of ice core data to reconstruct ancient climate data, which requires the careful extraction and characterization of air bubbles trapped within the ice. The third issue concerns the role of clouds in climate change, which indeed is one of the greatest sources of uncertainty regarding climate change. We also discuss other key uncertainties, such as the sensitivity of surface temperature to greenhouse gas concentration, the contribution of glacier melt to sea level rise, and the regional effects of climate change.

What society should do about climate change is fundamentally an ethical question. The answer to this question depends on our ethics–that is, on what we think is right and wrong or good and bad. Some skeptics might argue that we should not address climate change because of the expense involved in mitigation or adaptation, but the direct and indirect damages from climate change will be costly to businesses, governments, and individuals. Based on these cost considerations as well as a regard for human civilization in the future, a strong ethical argument can be made that society should prioritize reducing greenhouse gas emissions to reduce how much the climate will change.