The Terrifying Warning Lurking in the Earth’s Ancient Rock Record Peter Brannen Images above: Glaciers from the Vatnajökull ice cap, in Iceland Brendan Pattengale is a photographer who explores how color can convey emotions in an image. In his photo illustrations throughout this article, the colors of the original photos have been adjusted, but the images are otherwise unaltered. This article was published online on February 3, 2021. We live on a wild planet, a wobbly, erupting, ocean-sloshed orb that careens around a giant thermonuclear explosion in the void. Big rocks whiz by overhead, and here on the Earth’s surface, whole continents crash together, rip apart, and occasionally turn inside out, killing nearly everything. Our planet is fickle. When the unseen tug of celestial bodies points Earth toward a new North Star, for instance, the shift in sunlight can dry up the Sahara, or fill it with hippopotamuses. Of more immediate interest today, a variation in the composition of the Earth’s atmosphere of as little as 0.1 percent has meant the difference between sweltering Arctic rainforests and a half mile of ice atop Boston. That negligible wisp of the air is carbon dioxide.