The Planet Has Seen Sudden Warming Before. It Wiped Out Almost Everything. - The New York Times
The Siberian volcanoes ultimately delivered much more carbon dioxide into the atmosphere than we will ever emit by burning fossil fuels. But our annual rate of carbon emissions is actually higher.
The carbon we released over the past two centuries already has made the atmosphere warmer, and the ocean has absorbed much of that heat. And now, just as during the Permian-Triassic extinction, the ocean is losing oxygen. Over the past fifty years, oxygen levels have declined by 2 percent.
“The way the Earth system is responding now to the buildup of CO2 is in the exact same way that we’ve seen it respond in the past,” said Dr. Kump.
Just how much warmer the planet will get is up to us. It will take a tremendous international effort to keep the increase below about 4 degrees Fahrenheit.
If we proceed to use up all the fossil fuels on Earth, it could warm by as much as 17 degrees Fahrenheit by 2300.
As the ocean warms, its oxygen levels will continue to drop. If ancient history is any guide, the consequences for life — especially marine life in the cooler parts of the ocean — will be disastrous.