My last article about the chart I use in the header generated some interesting discussion. You can look back to see the types of comments that were made about it. The two headers can be seen here. For all the discussion about it, the charts didn’t change very much. That is because they both reflect the type of temperature behavior that the Northern Hemisphere (NH) has experienced for the past few thousand years.
The new chart is from the Penny Glacier on Baffin Island in northern Canada. The last data point from this core is a 25 year average from 1967-1992. One interesting fact about Baffin Island is that it contains the last remnants of the Laurentide Ice Sheet that once covered large parts of North America.
Perhaps the biggest difference between Penny Glacier and the GISP2 ice core is that Penny isn’t impacted by the Gulf Stream in the same way Greenland is. The Gulf Stream goes to the east of Greenland and Baffin Island is north of Hudson Bay to the west of Greenland. As a result there is less overall variation in the temperature record.
This likely makes the Penny Glacier ice core a better indicator of overall Arctic conditions for the past 6,000 years than the GISP2 because the Gulf Stream has less of an impact. This indicates that the current conditions in the Arctic are less unusual than what is commonly believed by many. While this may be a surprise to many, it is very comparable to the other Northern Hemisphere ice cores.
On time scales that are less than a few hundred years, it is impossible to tell if the overall trend is cooling or warming because it is almost always doing one or the other. Trends in the Earth’s climate are visible on the scale of thousands of years, not dozens of years. The trend for the past 6,000 years is cooling. The Penny records show this more clearly.
Any honest analysis of the isotope record will show that the current warming is nothing unusual. In fact, the warmest part of the past 200 years is not the current temperature, but 25 year average from 1892-1917. The record from Baffin Island is pretty straightforward in one respect. The current warming is nothing special in the history of the Arctic.
Anyone truly concerned about the Polar Bears should take heart from that. They have survived much warmer Arctic conditions than those that currently exist.
Tags: ice core