Carbon Cycle Feedback Weaker than Thought

Warming temperatures will not induce as significant an increase in atmospheric carbon dioxide as most computer models assume, reports a new study published in this week’s peer-reviewed journal Nature and summarized in Science Daily. As a result, alarmist computer models are predicting more global warming than is likely to occur.

Scientists have long known that rising temperatures – as a result of either natural or anthropogenic factors – lead to increases in atmospheric carbon dioxide. The higher atmospheric carbon dioxide levels serve as a positive feedback mechanism, amplifying the warming that spurred the higher atmospheric CO2 levels in the first place. Estimates of how much atmospheric CO2 is added to the atmosphere per degree Celsius of warming have greatly varied, with recent estimates gravitating around 40 parts per million (ppm).

A team of Swiss and German scientists conducted more than 200,000 individual comparisons of temperature and carbon dioxide from Antarctic ice cores dating back to the year 1050. They discovered that current forecasts of 40 ppm rise in atmospheric CO2 per degree Celsius of warming substantially overestimate real-world CO2 increase.  Rather than 40 ppm, each degree Celsius of warming induces roughly 7.7 ppm of additional atmospheric CO2.

“Our results are incompatibly lower (P<0.05) than recent pre-industrial empirical estimates of ~40 p.p.m. … and correspondingly suggest ~80% less potential amplification of ongoing global warming,” the study concludes.