Our local lake is still — barely — capable of supporting wakeboard boats, something I tested out yesterday in the photo above. It won’t be much longer, Lake Travis will simply dry up into Baked Mud Canyon if we don’t get a veritable deluge of rain in the next few months. But if present trends continue there could be plenty of water. Scientists working with Antarctic sediments have found a disturbing signal: the East Antarctic Ice Sheet, the largest ice sheet on earth today, melted partly or wholly during the Pliocene. And that pushed global sea levels up almost 200 feet (65 m), the only thing between us and the kind of rise is time, the GHG concentrations are about the same
NBC News — Scientists have long known that seas were higher during the Pliocene, a geological epoch that ran from 5.3 million to 2.6 million years ago. At the time, atmospheric carbon dioxide levels were similar to today’s 400 parts per million (ppm).
“Overall, it was a warmer climate than today, but similar to what we expect to reach by the end of this century,” Carys Cook, a graduate student at the Grantham Institute for Climate Change at Imperial College London and the study’s lead author, told NBC News in an email.
The West Antarctic and Greenland ice sheets were likely completely melted at the time, she added. The fate of the East Antarctic ice sheet has been less clear, though at least some of it must have melted to fully account for the highest global sea levels predicted by some reconstructions of the ancient earth.
Cook and her colleagues studied the chemical composition of sediments drilled from the ocean floor near East Antarctica. They identified the signature of a specific type of rock “only found in large quantities hundreds of kilometers inland from the current ice sheet edge,” Cook said.