Modern ‘Warmth’ A Brief Excursion From
8,000-Year (Continuing) Cooling Trend
The scientific literature is replete with evidence that the geological record for the Holocene (the last 10,000 years) fails to support the concept that rising atmospheric CO2 concentrations cause ocean and land temperatures to rise.
Actually, the scientific literature strongly suggests that the correlation between rising CO2 and temperature would appear to veer off in the opposite direction: as CO2 rises, temperatures decline.
So if there is a correlation for the Holocene, it may be the inverse of climate model expectations.
Modern ‘Warmth’ Excursion Has Had Little Or No Effect On The Overall Long-Term Cooling Trend
According to an estimate of global sea surface temperature (SST) changes during the last 2,000 years (“Robust global ocean cooling trend for the pre-industrial Common Era“), the addition of the last 2 centuries (1800 to 2000 C.E.) of relatively modest SST warming only changes the overall per-millennium global cooling trend (~0.4°C) by one tenth of one degree. In other words, using a long-term perspective, the Holocene cooling trend has continued largely uninterrupted during the last two centuries.
“Our best estimate of the SST cooling trend, scaled to temperature units using the average anomaly method (method 1), for the periods 1–2000 CE is –0.3°C/kyr to –0.4°C/kyr, and for 801–1800 CE is –0.4°C/kyr to –0.5°C/kyr“
Overall cooling has been ongoing for most of the last ~8,000 years, mixed in with temporary warming “spikes” that last for a century or two. The modern warming that emerged in the early 20th century will, if history is a guide, eventually revert back to the cooling trajectory of the last several thousand years. Gerhard (2004) facilely illustrates this overall global cooling trajectory — with swerves and spikes along the way.
CO2 Concentrations Rose Steadily Throughout The Last 8,000 Years…While Earth Cooled
While the planet has been steadily cooling (with brief warming excursions) for the last 8,000 years, atmospheric CO2 concentrations have tilted in the opposite direction, rising from about 260 parts per million (ppm) ~8,000 years ago to about 280 ppm in ~1800 C.E.
So if CO2 rises as temperature drops, the correlation suggested by climate models (temperature should rise as CO2 rises) is not supported by by a large portion of the available scientific evidence.
Listed below are 50 inverse “hockey stick” graphs featuring a long-term global cooling trend that is largely uninterrupted by modern era temperatures. These reconstructions illustrate the unheralded disconnect between CO2-driven climate models and the geological record.
“[P]roxy-inferred annual MATs [annual mean air temperatures] show the lowest value at 11,510 yr BP (7.6°C). Subsequently, temperatures rise to 10.7°C at 9540 yr BP followed by an overall decline of about 2.5°C until present (8.3°C).”
“A marine sediment record from off the shore of the western Antarctic Peninsula also shows an early Holocene optimum during which surface ocean temperatures were determined to be 3.5°C higher than present. Other evidence suggests that the George VI ice shelf on the southwestern Antarctic Peninsula was absent during this early-Holocene warm interval but reformed in the mid Holocene.”