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.
from E. D. Galbraith, S. Eggleston. A lower limit to atmospheric CO2 concentrations over the past 800,000 years. Nature Geoscience, 2017
During the ice ages, an unidentified regulatory mechanism prevented atmospheric carbon dioxide concentrations from falling below a level that could have led to runaway cooling, reports a team of researchers. The study suggests the mechanism may have involved the biosphere, as plants and plankton struggled to grow under very low carbon dioxide levels.
An international team led by researchers at Nagoya University, along with US and Swiss colleagues, has identified a new type of solar event and dated it to the year 5480 BC.
La géologie, une science plus que passionnante … et diverse
