The aim of this paper is to examine discounting of negative consequences of nuclear waste from both content-related and methodological perspectives. To test whether discounting depends on the issue at hand, we compare discounting judgments between nuclear and hazardous wastes. Further, we investigate psychological factors underlying discounting. From a methodological perspective, we investigate participants' sensitivity to extensive timescales. Data from an online experiment (N = 314) reveal two psychological discounting factors: The more participants belief that societies will be able to adapt to future challenges, the stronger they discounted negative future consequences. The more emotionally involved participants feel about the future the less they discounted. Seriousness judgments were higher for the issue of nuclear than for hazardous waste. The results also indicate that participants are sensitive to different extensive timescales. We discuss the implications of our findings for future research on discounting of negative long-term impacts of technologies.