Hi all, I read this article about a carbon dioxide driven climate change in the pre-historic past, (ca. 56 million years ago), World Without Ice. I quote below some predictions made by the scientists. I also would like to quote the Wikipedia about the fossil fuel resources available to us. Regards Peter Wikipedia, http://en.wikipedia.org/wiki/Fossil_fuel Years of production left in the ground with the current proved reserves and flows above Coal: 148 years Oil: 43 years Natural gas: 61 years Years of production left in the ground with the most optimistic proved reserve estimates (Oil & Gas Journal, World Oil)[citation needed] Coal: 417 years Oil: 43 years Natural gas: 167 years World Without Ice, http://ngm.nationalgeographic.com/2011/10/hothouse-earth/kunzig-text Matt Huber, a climate modeler at Purdue University who has spent most of his career trying to understand the PETM, has also tried to forecast what might happen if humans choose to burn off all the fossil fuel deposits. Huber uses a climate model, developed by the National Center for Atmospheric Research in Colorado, that is one of the least sensitive to carbon dioxide. The results he gets are still infernal. In what he calls his "reasonable best guess at a bad scenario" (his worst case is the "global-burn scenario"), regions where half the human population now lives become almost unbearable. In much of China, India, southern Europe, and the United States, summer temperatures would average well over 100 degrees Fahrenheit, night and day, year after year. Climate scientists don't often talk about such grim long-term forecasts, Huber says, in part because skeptics, exaggerating scientific uncertainties, are always accusing them of alarmism. "We've basically been trying to edit ourselves," Huber says. "Whenever we see something really bad, we tend to hold off. The middle ground is actually much worse than people think. "If we continue down this road, there really is no uncertainty. We're headed for the Eocene. And we know what that's like." .. Fossil fuel burning has released more than 300 billion tons of carbon since the 18th century?probably less than a tenth of what's still in the ground or of what was released at the PETM. That episode doesn't tell us what will happen to life on Earth if we choose to burn the rest. (Global emissions set another record last year.) Maybe there will be a burst of evolutionary innovation like the one that gave rise to our primate ancestors; maybe this time, with all the other pressures on species, there will be mass extinctions. The PETM merely puts the choice in long perspective. Tens of millions of years from now, whatever becomes of humanity, the whole pattern of life on Earth may be radically different from what it would otherwise have been?simply because of the way we powered our lives for a few centuries.