At the 1988 briefing in Boulder, “Future Climate/Future Life” served as the rubric for tandem presentations by Ralph Cicerone and the late Stephen Schneider, both at the time senior atmospheric scientists at the National Center for Atmospheric Research. Among the issues under scrutiny then: How fast – and how far – would temperatures rise in response to the rising levels of greenhouse gases? What were the sources and sinks of the various trace gases? What more did we need to know to better refine our assessment of Earth’s fate? Climate science has come a long way since in the quest for answers. In his return visit to New Horizons, Cicerone reflects on the journey that has brought us to where we are now in our understanding of the processes underlying climate change, and offers, from his unique perspective, a best-guess look at what looms.