It Was So Much Warmer Then

It looks like the polar bears will survive the current warming.

"We have this specimen that confirms the polar bear was a morphologically distinct species at least 100,000 years ago, and this basically means that the polar bear has already survived one interglacial period," explained Professor Ingolfsson.

"And what's interesting about that is that the Eeemian - the last interglacial - was much warmer than the Holocene (the present).

"This is telling us that despite the ongoing warming in the Arctic today, maybe we don't have to be quite so worried about the polar bear. That would be very encouraging."

So what do we know about the Eeemian?

The Eemian interglacial era (known as the Sangamon interglacial in North America, the Ipswichian interglacial in the UK, and the Riss-Würm interglacial in the Alps) is the second-to-latest interglacial era of the Ice Age. It began about 131,000 years ago. Changes in orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as the Milankovitch cycle, probably led to greater seasonal temperature variations in the Northern Hemisphere, although global annual means temperatures were probably similar to those of the Holocene. The Eemian climate is believed to have been about as stable as, but probably warmer than that of, the Holocene (see ice core). The warmest peak of the Eemian was around 125,000 years ago, when forests reached as far north as North Cape (which is now tundra) in northern Norway well above the Arctic Circle at [show location on an interactive map] 71°10′21″N, 25°47′40″E. Hardwood trees like hazel and oak grew as far north as Oulu, Finland. Sea levels at that time were 4-6 meters higher than they are now, indicating greater deglaciation than today (mostly from partial melting of the ice sheets of Greenland and Antarctica). One study published in July 2007 found evidence that Dye 3 was glaciated during the Eemian, which implies that Greenland could have contributed at most 2m to sea level rise. Scandinavia was an island due to the inundation of vast areas of northern Europe and the West Siberian Plain.

At the peak of the Eemian, the northern hemisphere winters were generally warmer and wetter than now, though some areas were actually slightly cooler than today. Trees grew as far north as southern Baffin Island in the Canadian Arctic Archipelago instead of only as far north as Kuujjuaq in northern Quebec, and the prairie-forest boundary in the Great Plains of the United States lay further west — near Lubbock, Texas, instead of near Dallas, Texas, where the boundary now exists. The era closed as temperatures steadily fell to conditions cooler and drier than the present, and by 114,000 years ago, a glacial era had returned.

Did any one notice the bit in the first paragraph about Earth being in an Ice Age? And the fact that the interglacial periods are only temporary respites. We really need to worry more about a return of an ice age. Very few crops do well under ice.