A short, inconspicuous article, “Clues to how Mayan world dried up” [news, Aug. 6], revealed a startling insight into the ongoing debate on human-induced climate change. It is true that over hundreds of thousands of years, the Earth’s climate has fluctuated wildly (ice ages, extreme heat and drought) and will continue to do so; however, the effect of human activity, which began only about 150 years ago, is unprecedented. What we humans need to worry about is the timing of natural cycles and human-induced climate change. Whereas a natural cooling cycle could temporarily mitigate global warming, the inevitable coincidence of natural and human-induced warming would be catastrophic.

This argues for intensive, science-based analysis of the Earth’s climate to understand the effects of human activity and predict naturally occurring cycles of climate change. This article should be required reading for all citizens (particularly politicians of all stripes) who are concerned with the Earth’s climate.

B.K. Krueger, Ellicott City