Climate [existental] change? Climate [science]
Long before we thought we knew what climate was, and that it is existentially changing, was a pair of events between 2.somenting billion years ago, and about 580 milion years ago. A pair of ice ages, both so severe, the entire Earth was buried in ice. Yet, therre was active volcanism. Real, erupting volcanoes, with ejected ash and gasses in to the air, corrupting the atmosphere to a greater degree than we observe now, even though man was yet to set foot on the Earth. Lomg before. Imagine that. Natural-caused greenhouse gasses? Yup.
And ice covered for so long, nothing but single-celled creatures survived while that last severe ice age was retreating, finally. Yup. No man, but catstrophic climate, anytway.
Advanve to 1869. American geologist, John Wesley Powell observes, to his surprise, an anomoly on the Grand Canyon wall, sediment that is set on a severe angle, representing the first thrust of the Rockies, and, immediately below it, horizontal sediment deposts. No surprise there; this has been witnessed repeated times around the globe on canyon walls. The problem, Powell discovered, was that the upper, diagnonal deposits, dated at 580M years ago. Immediately below, the horizontal deposit dated at 2.something billion years ago. How and why the intrerruption in dating? To make a long story short, the anomoly was called the Great Nonconformity. It is theorized that as that last long-enduring ice age ended, and with continued volcanism in play, the glaciers were warmng rapidly, melting and moving from the Great Lakes south and west, grinding and removing 1.2B years of sediment layers. Poof. Ground and gone, to be covered once again by more sediment layers [oin Bonneville Lake, a vast sea in its ancient time that extended from east of the evential Mississippi River to the thrust of the Rockies. Man is estimated to make the scene much later, around 100-200k years ago. In geologic time, a blink.
WHAT? Climate change before man? Damn!