The Earth during the early Eocene was an alien planet. Massive crocodiles prowled the warm waters off Greenland, hundreds of miles above the Arctic Circle, while palm trees grew in what’s now Alaska. Long, slender whales swam through oceans that were almost 200 feet higher than they are today. It was a time of tiny mammals and snakes longer than a bus. It was the world where birds eat horses. And now, in a sense, that world is coming back.
Continuing to burn fossil fuels at the current rate could bring atmospheric carbon dioxide to its highest concentration in 50 million years, jumping from about 400 parts per million now to more than 900 parts per million by the end of this century, a new study warns.
While it’s beyond unlikely that Gastornis will be showing up to trot around suburban lawns in pursuit of pets, the temperatures and the shorelines that came with the Eocene’s extremely high temperatures are almost certainly on their way if emissions continue unchecked.
The new study speaks to the power of human influence over the climate. It suggests that after millions of years of relative stability in the absence of human activity, just a few hundred years of anthropogenic greenhouse gas emissions are on track to cause unprecedented warming.
If matching 50 million years of change in a century seems severe, it’s small potatoes compared with where we could get if we fail to get our act together.
If greenhouse gas emissions continue unabated beyond that point, the climate could reach a warming state that hasn’t been seen in the past 420 million years.
And 420 million years ago would land us near the end of the Silurian Period, a time when the world was dominated by warm, storm-wracked oceans and the most complex life on land was moss and millipedes.
For an individual human, the world can seem enormous, and the idea that our actions can sway something as grand as the climate may not seem obvious. But there are billions of us, and together our actions are frighteningly powerful.
The findings suggest that, until humans started rapidly burning fossil fuels with the advent of the Industrial Revolution, Earth’s climate had been relatively stable for millions of years, and carbon dioxide concentrations were declining. Thanks to the human emission of greenhouse gases, though, that’s all changing at record-breaking pace. …
On a business-as-usual pathway — a trajectory in which greenhouse gas emissions would continue at their current rate — carbon dioxide concentrations will hit a level that hasn’t been seen in 50 million years, according to the research.
At the current rate of emissions, we’ll have the world at Eocene levels by 2100. By 2250, we’d have levels that came around at the rise of the dinosaurs. And come 2400, we’d be back before the first fish poked their heads from the ocean.
Unfortunately, humans not only tend to think of themselves as too small to shape the world, they also tend to think of time in short spans. Forget 420 million years, even mentioning something that happens in 2400 seems to provide plenty of opportunity for change.
So it’s worth noting that right now, today, CO2 levels have moved from 280 ppm to over 400 ppm. They will never be below 400 ppm again in the lifetime of anyone reading this article.
The last time levels were that high, was about 3 million years ago. Temperatures at that time stabilized at between two and three degrees centigrade above the current level. At that point, all of Florida below the panhandle was underwater. Not “the coastlines were a little different.” Florida was underwater. And yes, that includes Mar-a-Lago. That’s where we are now.
Of course, the seas aren’t going up 82 feet overnight. Ivanka or Trump Wife #4, whichever one is younger, might still be able to live on the top floor of the resort after the sea comes up just two meters in the next fifty years or so. But that’s only because it takes awhile to melt all that ice that was millions of years in the making. It is melting. Right now.
Drip, drip, drip.