Pliocene Warmth

13 Jul 2010

At July 13th ... we are informed, soaring Arctic temperatures may have almost reached tipping point. However, before dismissing this as just another scary tale funded by AGW 'big money' grants, we need to find out why they think the Arctic is so sensitive to what has been so far a minimal amount of warming. It stems from a connection made between the modern world and the Pliocene epoch. Mean average temperature on Ellesmere Island in the High Arctic during the Pliocene, some 2.6 to 5.3 million years ago, preceding the Pleistocene era of the Ice Ages, were warmer then than they are now - yet C02 levels were only slightly higher. This is the assumed evidence of a tipping point - the level of C02 in the Pliocene was 400 parts per million as opposed to 390 parts per million currently - and C02 drives climate. Doesn't it?

During the Pliocene Ellesmere Island had a flora that included forests of larch, dwarf birch, and northern white cedar plus a variety of mosses and herbs (such as cinquefoil). It wasn't particularly warm, it might be noted, although in one location fish and frogs in a pond environment were found, as well as a general population of dwarf deer and dwarf beaver, horses, black bear, rabbits, badgers, and shrews - all thriving in a location that was supposed to have had no daylight for six months of the year (which is the case nowadays). That, in itself, should have raised an eyebrow - but apparently it did not. The poles are immutable - they have remained in the same position for countless millions of years. In addition, that is also a side issue - it is the switch from warmth to cold conditions between the Pliocene and the Pleistocene that interested the researchers. Shifting axis soil the type-face.

Many plants and animals, it seems, were preserved in peat deposits (indicating excessively wet weather at some stage) - pickled like the bog bodies of Europe (Iron Age). When reading the report - deliberately couched in scary adjectives, we may note that one lead author said, 'I can't help but wonder if the Arctic is headed towards conditions similar to those in the Pliocene' - presumably pushed in that direction by the forewarned tipping point. Is this such a bad thing?

Actually, a tipping point can only be supposed if the Poles had not moved in the last 3 to 5 million years or so, or if continental drift was excruciatingly slow. Ellesmere Island is to the north west of northern Greenland but could it have been warmer as a result of Pole shift. In the Pliocene it is assumed there was no ice at the North Pole - and this only happened during the Pleistocene (the tipping point operating in the opposite phase, warm to cool). However, I can recall Allen and Delair, in When the Earth Nearly Died, making the point that the Pleistocene is an invented geological epoch created solely to accommodate the Ice Ages - an add-on to the geological chronology of the past. They toyed with the idea that in fact the Pliocene ran largely contemporary with this new epoch of the Ice Ages, which in effect meant the Pliocene did have ice at the poles - but those poles were not where they are today (but because ice has been on Antarctica for considerably longer than Greenland it could not have been too far from where it is now). In effect, the Pliocene, in their revised scheme, would have come to an end around 17,500 years ago, contemporary with the end of the Late Glacial Maximum, whereas the Pleistocene rumbled on until the Younger Dryas Event, 12,900 to 11,600 years ago (or roughly so as the specifics as far as dating is concerned seem to vary from source to source). If an actual pole shift is unfeasible it may be that a change in the axis of rotation, the amount of tilt, took place - but there are some very real problems. I mention this solely in order that members might ponder on such a possibility - not as an indicator that such things might be a reality. Once you read such papers with these sorts of things in mind a different interpretation than that of the authors is construed - honestly or otherwise.