Tipping Point?
21 hours ago Guest Blogger 76 Comments
by Kirby Schlaht
Many climate catastrophists claim that only a few more degrees in temperature or a few parts per million of a greenhouse gas might push our planet over the edge into a devastating hothouse environment with warming oceans, melting ice caps, rising sea levels, and more violent storms. Are tipping points unprecedented in paleoclimate history with rapid temperature changes leading to extreme warming or cooling climates? Let’s look at some paleoclimate data for ourselves.
Fossil foraminifera can be used to identify the conditions in which the enclosing sediments accumulated. We can use the oxygen-18 ratios to recognize glacial and warm episodes during the current Ice Age. We know that during the last million years of the Late Pleistocene Ice Age the planet has continued to cool initiating a glacial-interglacial period of around 100 thousand years. The Milankovitch 100k year orbital Eccentricity cycle appears to modulate this longer period. Over the previous 2 million years of the early Pleistocene the planet was warmer with the glacial-interglacial period a steady 40 thousand years seemingly driven by the 40k year Obliquity cycle.
High resolution paleoclimate proxy records from Greenland ice cores (Boers, 2018) show that the last 120-thousand-year glacial interval was punctuated by abrupt climatic transitions called Dansgaard–Oeschger (D-O) events. These events are characterized by rapid temperature increases over Greenland of up to 15 deg C within a few decades. The course of a D-O event starts with an abrupt warming, followed by a cooling period lasting a few hundred years where temperatures eventually return to the normal cold of the glacial period. The cause of these transitions remains unclear. However, these transitions may be influenced by amplification of cyclic solar forcings,
https://wattsupwiththat.com/2024/05/07/tipping-point/
