Earth is an Anthorpogenic Climate Change Denier

Editor

It’s worth revisiting NASA’s Gavin Schmidt’s claim, as reported in your ICO Editor’s Reply, that now “…could be the warmest period since the dawn of civilization.” In my two previous letters on this subject I referenced studies of trees growing in far northern latitudes 9,000 to 5,000 years ago where they can’t grow now, and of coral mounts from the same period that are several feet above present sea level. Both are obvious signs that we couldn’t be in a warmer period now.

For other examples that totally debunk Schmidt’s statement that now is probably the hottest period in the Holocene – the past 11,500 years - we should add Alpine glaciers and tree lines. Prof. Gernot Patzelt, an internationally renowned glaciologist with numerous publications and lectures, authored (title translated from the German) “Glaciers: Climate Witnesses from the Ice Age to the Present.” Patzelt found that for 70% of the past 10,000 years, glaciers were smaller than now. This finding supports studies of Greenland ice cores (“The Two-Mile Time Machine,” Richard Alley) and a variety of ocean and lake sediment cores that indicate that 90% of the past 10,000 years were warmer than the present.

Concerning tree lines, Patzelt noted: “Around (10500 BP - Before Present) the temperatures were lower, from (10200 BP) they were already above the level of the present temperature conditions… the postglacial warm period reached a first peak shortly after (8000 BP), followed by a second peak around (6200 BP). During this time … the timberline was 100-130 meters (328-426 feet) higher than what is currently possible, which means that a summer temperature of 0.6-0.8 °C (1.0-1.3 °F) higher can be derived…” (Bolding added by me for emphasis; dates changed from BC to BP for clarity)

Trees, corals, glaciers, ice sheets – we can learn from them.

Earth's Experiment Continues

Editor

The Editor’s Reply to my “Earth’s experiment” letter emphasized the lack of precision and uncertainty of scientists’ estimates of ancient global temperatures. While I would strongly differ with you alleging imprecision in the two-mile Greenland ice cores that indicate that we now live in the coldest 1,000-year period of the past 10,000, the purpose of my letter was to show that tree-rings and other proxies of temperature are not relevant to the determination that Earth was much warmer and sea levels significantly higher during the Holocene Climatic Optimum (9,000 to 5,000 years before present). 

However, since you quoted NASA’s Gavin Schmidt speculating that “…the Earth as a whole is probably the hottest it has been during the Holocene – the past 11,500 years or so…”, so I Googled “Holocene Climatic Optimum” and clicked on the Wikipedia link. There I found many references to hotter periods than the present without the use of Schmidt’s “probably” to convey Holocene climate change. 

Getting back to the Earth’s experiment, many signs of earlier hotter periods in the last 10,000 years are scattered all over the Earth’s surface. In Northern Europe, Asia, and Canada scientists found and carbon-dated tree stumps that proved that forests advanced to or near the current arctic coastline between 9000 and 7000 years ago and retreated to their present positions by between 4000 and 3000 years ago as Earth cooled.

Changes in sea level serve as Earth’s thermometer. Studies of fossil corals worldwide show that sea levels were much higher during warmer periods. During the most recent past interglacial period (125,000 years ago), sea level was over 26 feet higher than now, proof that temperature was also much higher. 

The NOAA U.S Climate Reference Network shows no significant warming since NASA created it in 2005. Mr. Schmidt “probably” doesn’t want to know.

The Earth's Natural Climate Change Experiment

Editor

The Earth conducted an experiment over the past three million years that charted climate change against atmospheric CO2. After comparing glacial and interglacial periods to CO2 levels, Earth’s finding was that there was no correlation. Several interglacials were noted that were warmer with much higher sea levels than the Holocene interglacial with atmospheric CO2 levels of 280ppm. Slightly lower CO2 levels were noted during glacial periods which ended before CO2 levels increased moderately. For the past three million years interglacials began when CO2 was low and ended when CO2 was higher. 

The same proved true for shorter periods since 1900; temperature rose rapidly from 1920 to 1940 with little or no change in CO2 from 280ppm. Then as CO2 rose rapidly after 1940, global temperature fell rapidly until 1980. The rise in both temperature and CO2 from 1980 to 2000 was followed by a pause in temperature increase that persisted almost twenty years while CO2 continued to steadily rise. 

Looking at just the past 10,000 years, Greenland ice core and lake and ocean sediment cores show we now live in the coldest 1,000-year period of the past 10,000 years, and that the greatest warming and corresponding higher sea levels were found 6,000 to 8,000 years ago during the Holocene Climate Optimum. The following three warming periods before the present – Minoan, Roman, and Medieval – were each cooler than its predecessor and current warming is the coolest of all. 

Proof of warmer periods in the past 10,000 years are also evidenced by ancient tree lines further north and at higher altitudes, coral mounts several feet above current sea level, and ancient beaches above present ones. 

Thousands of studies exist that prove earlier warming was significantly higher and globally distributed. The Earth gives evidence that none of the models can refute.