Geological Time and Climate Change - Bryan Lovell
55 million years old Hertfordshire Puddingstone Science Museum specimen
The Earth is 4500 million years old. This is an almost incomprehensible length of time, but we can compress those billions of years into a more familiar timescale. Let’s take a calendar year, and imagine that Earth came into being just as the new year was coming in. The earliest signs of life in the fossil record are found in rocks over 3000 million years old, in the spring of that imaginary year. The first animals with hard parts preserved as fossils did not appear until November. The dinosaurs flourished from mid- December, before becoming extinct shortly after Christmas. Jesus Christ lived and died about 14 seconds before the end of the year. Our own lives represent only a fraction of the last second of the year.
What can we latecomers learn about climate change from studying that long geological record? Thanks to recent advances in dating events recorded in ancient rocks, we can now look at past changes in Earth’s climate over episodes of thousands rather than millions of years. As a result, geologists can now provide strong independent confirmation that we really do have a serious problem with human-induced climate change.
Gestures, Photo by Camilla Greenwell
Science Museum video with Dr. Bryan Lovell
55 million years ago (“late December”), there was a natural, sudden large release of carbon to Earth’s atmosphere. That release was of a size, and at a rate, comparable to the way in which we are now dumping carbon into the atmosphere ourselves. There are other similar releases of carbon seen elsewhere in the geological record. Each such release caused major disruption in Earth systems, from which the planet took hundreds of thousands of years to recover. We are repeating an experiment on the whole planet to which we already know the threatening answer. Those messages from deep geological time tell us that the planet will survive if we persist in our own rapid and large release of carbon. These messages from the past also tell us that we might well not be so fortunate. Homo sapiens, mend your ways. Quickly.