The journey of Teilhardina is one we would do well to consider. We are now injecting carbon dioxide into the atmosphere at about the same rate at which it was released 55 million years ago. The Paleocene-Eocene boundary may offer some clues to how the world's ecosystem may respond. Some species may become extinct--particularly marine species that won't be able to cope with the acidity of the oceans. Others will spread. Teilhardina covered 20,000 kilometers in less than 25,000 years. That's hardly supersonic. In fact, it matches the rate of dispersal scientists observe in mammals today--about a kilometer a year. But Teilhardina spread at this rate year in and year out, and before too long (geologically speaking) it had circled the globe. If we ever do figure out a way to cut off our carbon emissions, the carbon we've already put in the atmosphere may last for a long time. In the Eocene, the planet took 70,000 years to recover. But the ecological changes were far more durable. Primates managed to stick around in North America for about 20 million years, until the climate had cooled too far to support the forests they depended on. The Earth's planet has continued to cool and carbon dioxide levels have continued to drop. That means that the current climate change will not be a perfect replay of the crisis 55 million years ago. But it does serve as an example of how a pulse of global warming can do some remarkable things, such as putting primates in Wyoming for 20 million years.
Carl brings up some very important points. It dovetails very nicely with a presentation that I sat in at our all hands meeting shortly after I came to NERSC. The presenter pointed out that the findings of the climate scientists were going to piss off both conservatives and greens alike. First the fact was the Global Warming was happening and being caused by humans - the conservative pisser - and that it would take human intervention on the part of removing the CO2 to fix the problem: merely to stop putting carbon dioxide into the atmosphere does not fix magically the problem - the pisser for the Greens.
Do we end up with an Eocene earth? Or an Oligocene? If its the latter, we're in trouble here in the States. Something to consider.