The climate of Earth is changing, imperiled by the relentless emission of greenhouse gases from our advancing civilization. The Arctic sea ice cover is disappearing, creating land and sea conditions never experienced in human history. Sea levels are rising, imperiling coastal communities where much of humanity resides. Precipitation patterns are changing, resulting in long periods of drought, imperiling our sources of food and reducing habitable locations. In an essay, The Climate Crisis. A Time of Peril. A Time to Act., COSPAR President Len Fisk calls upon all nations to address the climate crisis, with urgency, deliberately, and with guidance provided by science, for our sake and that of all future generations. The essay is published here, in the August issue of Space Research Today (SRT), A Forum for Discussion, and in the latest COSPAR News, Issue 9, with the expectation that it will result in discussion and comments.