Industrial Revolution Ended 1800 Year Ocean Cooling Trend

The high frequency and magnitude of volcanic eruptions could have been the cause of the progressive cooling of ocean surfaces over a period of 1,800 years. This is made apparent in an international study published recently in the journal Nature Geoscience, involving researcher P. Graham Mortyn of the Institute for Environmental Science and Technology (ICTA-UAB) and the UAB Department of Geography.

The study emphasises that this trend came to an end with the beginning of the Industrial Revolution and the resulting global warming caused by human activity. It further shows that the lowest temperatures in the first 1,800 years of the Common Era were recorded between the 16th and the 18th centuries, a period known as the "Little Ice Age".

Earlier research had already shown that volcanic explosions cause the atmosphere to cool. The present study demonstrates that the oceans can absorb and capture more heat than the atmosphere over longer periods of time, thus attenuating global temperature changes in the short term. These alterations in temperature can be prolonged when the volcanic eruptions are concentrated into a short space of time.

These findings bring a new perspective to the study of regional and global variations in ocean-surface temperature over the centuries, before the appearance of anthropogenic (human activity-induced) climate change.

The researchers combined, for the first time, 57 previous works on sea-surface temperature changes, which are calculated from fossil remains extracted from oceans all over the world, from the Poles to the Tropics. The results were compared with data from terrestrial indicators, such as tree rings or ice cores. These revealed a similar cooling trend.

link.

booyah.  called it.  Waaaaay back, I wondered if the Little Ice Age was ended by the industrial revolution.  The timing was suspicious.  I was poopooed back when because folks said the Maunder Minimum was the driving cause of the LIA.  It turns that the Maunder Minimum came too late to be the driver and the cooling trends were far, far older.  So, with this, we have a little bit more supporting the idea we were headed out of an interglacial and back into another glaciation.  Humanity stopped it and may have ended the Quaternary Ice Age altogether.  The cost though...

If I ever get around to it, the alternate history I'd dreamed up called the Grinding of Glaciers fit this scenario.  (I also have a half finished alt-hist of the Romans in the Americas, Epylium Aurelia).

NeoTethys Seawater was Oxygenated, but had Increasingly and Rapidly Warming Temperatures Just Before the Permian Extinction

Neotethys seawater chemistry and temperature at the dawn of the end Permian mass extinction

Authors:

Garbelli et al

Abstract:

The end of the Permian was a time of great death and massive upheaval in the biosphere, atmosphere and hydrosphere. Over the last decades, many causes have been suggested to be responsible for that catastrophe such as global warming, anoxia and acidification. The Gyanyima limestone block was an open ocean seamount in the southern Neotethys at subtropical latitude, and it affords us insight into open-ocean oceanographic changes during the end of the Permian After careful screening using multiple tests, we reconstructed carbonate/seawater curves from the geochemical data stored in pristine brachiopod shell archives from the shallow water limestone of the Changhsingian Gyanyima Formation of Tibet. The reconstructed strontium isotope curve and data for the late Changhsingian is relatively invariant about 0.707013, but in the upper part of the succession the values become more radiogenic climaxing at about 0.707244. The 87Sr/86Sr curve and trend is similar to that observed for the Upper Permian succession in northern Italy, but dissimilar (less radiogenic) to whole rock results from Austria, Iran, China and Spitsbergen. The Ce/Ce* anomaly results. ranging from 0.310 to 0.577 for the brachiopods and from 0.237 to 0.655 for the coeval whole rock before the event, and of 0.276 for whole rock during the extinction event, suggest normal redox conditions. These Ce* values are typical of normal open-ocean oxic water quality conditions observed in modern and other ancient counterparts. The biota and Ce* information clearly discounts global anoxia as a primary cause for the end-Permian biotic crisis. Carbon isotopes from brachiopod shells and whole rock are relatively invariant for most of the latest Permian interval, which is in stark contrast to the distinct negative carbon isotope excursion observed near and about the event. Estimates of seawater temperature at shallow depth fluctuated from 22.2 to 29.0 °C up to unit 8-2, and then gradually rise from 29.7 °C in unit 8-13 to values exceeding 35 °C at a stratigraphic level about 120 ky before the Permian-Triassic boundary, and just before the onset of the extinction interval. This dramatic increase in seawater temperature has been observed in global successions from tropical to mid latitude and from restricted to open ocean localities (e.g., northern Italy, Iran). The brachiopod archive and its geochemical proxies from Tibet support the paradigm that global warming must have been an important factor of the biotic crisis for the terrestrial and marine faunas and floras of the late Paleozoic world.