Archive for July 18, 2019

Anthropogenic Climate Change is a Form of Secular Apocalypticism: 3

July 18, 2019 13 comments

In the previous part of this series, I wrote about how there is lots of paleontological evidence that Antarctica (as late as 2.6-2.3 million years ago) was much warmer than it is today. This becomes extremely relevant to any debate about anthropogenic climate change since its ardent believers keep harping about how greenhouse gases released by human activity will, directly and indirectly, cause the ice sheet at both poles to melt and causes sea level rises not seen in many millions of years. As readers have probably figured out by now, the biggest problem with this argument is that Antarctica was far less glaciated until the last two million years. To put it another way, that continent was much warmer over millions of years when the atmospheric CO2 was either equal to or less than current levels. And this occurred while the continents were at their current positions.

So let us talk about paleontological evidence for the most recent forests on that continent. But before that, have a look at first figure (below) to familiarize yourself with its major geographical features- as they appear today. As you can see, Antarctica looks like two continents smushed together and that is sorta correct. Based on surveys using ice-penetrating radar, the larger part aka East Antarctica looks like just another continent with plains, hills and mountain ranges. West Antarctica, on the other hand, is dominated by a striking series of parallel mountain ranges and an unusually wide continental shelf. Note that removing all that ice would cause some of the land currently below sea level to rebound due to isostatic rebound. Here is another link to what lies under that thick ice sheet. Antarctica is like a larger and more mountainous version of Australia.

The 2nd longest mountain range in Antarctica, which partially sticks above the ice, is known as the Trans antarctic mountains or TAM. FYI, the longest one in that continent is found in West Antarctica and is known as the Antarctandes Anyway, back to TAM. You might notice that parts of this range runs pretty close to the geographical south pole. One of the main passages through this range to the polar plateau beyond is a very long and large glacier known as the Beardmore Glacier. One of first famous and tragic attempts to reach the south pole used this route, and oddly enough, is relevant to this topic. The exposed fossil bed of interest aka Oliver Bluffs is located near this glacier. While the plant fossils at this site were first reported in the late 1980s, there is good evidence that Robert Scott of the ill-fated expedition in early 1910s might have discovered this site since he described finding fossilized leaves similar to northern beeches.

Anyway, as you can see in the third figure (below) this area is now very cold, icy and devoid of plant life. While a few coastal areas of Antarctica, especially north of 65 degrees South do have some vegetation- most of it is of the non-vascular type. To date, only two species of vascular plants (Deschampsia antarctica and Colobanthus quitensis) have been found on that continent and they look like stunted shrubs. Oliver Bluffs, on the other hand, is at 85 degrees South and less than 500 km from the south pole. So why did a site that is 20 degrees south to the most southerly parallel currently capable of supporting any vascular plant life host a forest with decent sized southern beech trees and an undergrowth of other plants. More importantly, how was this possible as late as 2-3 million years ago when atmospheric CO2 levels were lower than today?

The fourth figure (below) is a composite of some photographs taken at that site. You might notice that the quality of fossilization is pretty good and one of the layer containing them is sandwiched between two glacier-derived layers implying that that the region went through repeated rounds of glaciation and reforestation. And this brings us to the next question- where did all those seeds for regrowth of these trees come from? While it is not totally impossible that those seeds were dispersed by birds from other continents, the nearest place with such trees (New Zealand) is about 4,000 km away. In other words, it is far more likely that there were more local and permanent forests containing such trees on the Antarctic mainland. But this would mean that a significant part of Antarctica , especially north of 75-70 degrees South and near the ocean was not covered by an ice sheet. Moreover, even the inland ice sheets at that time must have been significantly thinner and smaller than today. So what was going on?

Here is one recent and accessible paper which goes into some detail about various methods used for reconstructing temperature conditions at the Oliver Bluffs site. As you can see, these plant fossils have been dated to the Pliocene (5.3-2.6 million years ago) for past thirty years. Also scientists have been talking about their implication on the climate of that region for almost that long. While some have tried to dispute the dating of these fossils, it is increasingly clear that they do indeed come from somewhere between 4 and 2.6 million years. For example, analysis of pliocene marine sediments from an offshore drill core dated to between 5 to 2.2 million years and over a thousand km from the site with those plant fossils has revealed the presence of fossil nothofagous pollen including from the species found at Oliver Bluffs.

To quickly summarize, there is evidence that many coastal regions of Antarctica were about 30 degrees Celsius warmer than today and resembled parts of Northern Canada, Inland Alaska and Northern Russia during the late Pliocene (2.6-2.3 million years ago). It is also likely that the inland icesheets during that era were significantly thinner and smaller than those present today. Let me remind you that this was during a time when atmospheric CO2 levels were identical or lower than those seen today. Are you beginning to see the problem with current propaganda driven narratives about “global warming” and “anthropocentric climate change”?

What do you think? Comments?