An Arctic free of ice and stocked with swamp-loving reptiles. Temperate forests covering Antarctica, thriving on heat that kept them alive through the dark months. Average temperatures along the equator of about 100 degrees Fahrenheit.
High carbon dioxide levels kept the planet warm enough to sustain that life 50 million years ago during the Eocene Epoch. As the CO2 levels dropped, the planet tilted toward a cooling, and the ice caps were formed, choking off the life that once thrived at the poles.
Now, humanity’s consumption of fossil fuels is pushing the planet toward the CO2 levels of the period when dinosaurs roamed the Earth. And that’s the rosier scenario for 200 years from now, a new study has found.
By 2300, there would be little precedent for the transformation of the Earth. That’s because humanity’s billowing of CO2 into the atmosphere, chiefly through the consumption of fossil fuels, may be on track in a few centuries to hit a level not seen in 420 million years, according to the findings published yesterday in Nature Communications.
Eocene Epoch: 使新世。
Chok off: 阻塞。
Billowing: adj. 如波浪般翻滚的。