Tipping point? – Watts Up with that?

by Kirby Schlaht

Many climate catastrophe researchers say that just a few degrees of temperature increase or a few parts per million of greenhouse gases could push our planet to the brink of a devastating greenhouse environment with warm oceans. rise, melting ice caps, rising sea levels and more intense storms. . Are tipping points unprecedented in paleoclimatic history with rapid temperature changes leading to extreme warming or cooling? Let’s look at some paleoclimate data for ourselves.

Fossil foraminifera can be used to determine the conditions of surrounding sediment accumulation. We can use the oxygen-18 ratio to identify glacial and warm periods in the current Ice Age. We know that during the last million years of the Late Pleistocene Ice Age, the planet continued to cool, initiating a glacial-interglacial period that lasted about 100 thousand years. Milankovitch’s 100-thousand-year orbital eccentricity period appears to regulate this longer period. During the last 2 million years of the Early Pleistocene, the planet was warmer with a stable 40-thousand-year glacial-interglacial period that appeared to be driven by a 40-thousand-year oblique cycle.

High-resolution paleoclimate proxy records from Greenland ice cores (Boers, 2018) show that the last 120 thousand years of glaciation were punctuated by abrupt climate shifts known as the v. Dansgaard–Oeschger (DO). These events were characterized by rapid temperature increases over Greenland of up to 15 degrees Celsius within a few decades. The course of the DO event began with sudden warming, followed by a cooling period lasting several hundred years, where temperatures eventually returned to the normal cold levels of the ice age. The cause of these transitions remains unclear. However, these transitions can be influenced by the amplification of cyclic solar forces,

In 2017, Jung-Eun Lee and colleagues published model results showing that global cooling was the main driver of the glacial-interglacial temporal transition. Models show that the current state of our Milankovitch orbit is apically highly oblique and apically highly eccentric. If we plot proxy-18 temperature against the obliquity and eccentricity of the orbit during the last glacial period, a pattern emerges. We find high DO event frequency during high obliquity periods and low frequency during low obliquity periods with warm ice intervals occurring only at high obliquity and high eccentricity. High obliquity alone cannot initiate an interglacial period during periods of low eccentricity but it can provide enough increased insolation at higher latitudes – a tipping point if you will – to allow Changes in solar activity promote DO temperature transfer across sea ice and thereby reduce ice albedo. The slow return of low temperatures before the DO event represents a slow regeneration of sea ice and leads to increased ice albedo. During periods of low obliquity, our cooler planet suppresses or eliminates the effects of solar activity, thus lacking DO events.

I do not mean to imply that obliquity and eccentricity and changes in solar activity are the only factors leading to rapid climate change of this type of DO but that these external influences predispose Subject to internal factors such as changes in ocean currents or reductions in ice albedo could then show their warming influence. Climate change is not just one thing but represents a set of intertwined influences – however, I believe that changes in solar activity during DO event instances as well as the timing of the period glacial-interglacial, “prompted” by Milankovitch cycles provides another causal link in the causal chain.

Just to clarify – technically, Milankovitch cycles are not the first cause-and-effect link to any climate change. IN The story of climate change (https://thestoryofclimatechange.substack.com ), I present a chain of hypothetical causes of climate change in order of effect. It begins with the galactic orbital position of our planetary system (the spiral arm or interarm greenhouse), followed by the in-plane and out-of-plane orbital wobble positions of our galaxy. us (warm out-of-plane and cool in-plane), followed by Milankovitch orbital periods (obliquity, eccentricity, precession) especially notable during cold glaciations, followed by changes in solar activity, ultimately with the internal influence of ice albedo, ocean currents, water vapor and other short-term drivers such as volcanism. So where are we now? The current state of our climate is as follows: We are about 1/3 of the way through the Sagittarius spiral arm – we continue to fall deeper into the cold Icehouse. Our out-of-plane galactic orbital oscillations place us completely in-plane with the associated maximum cosmic radiation and maximum tendency for cloud cooling and the onset of the Ice Age. We are at the highest obliquity and eccentricity of the planet leading up to this 20 thousand year interglacial period. At these warmer temperatures, changes in solar activity are muted and give rise to events driven by the solar cycle over decadal to century-long timescales.

Are we at a Hothouse tipping point now? The simple answer is no.” The Greenhouse Age is simply not possible in our current climate. We will emerge from this Icehouse in about 125 million years and enter into the next Greenhouse by exiting this cold Sagittarius spiral arm space and passing through the next hot interarm zone that was last moved by our system 500 years ago million years during the Cambrian Period, the period that produced the “Cambrian Explosion,” the most violent burst of evolution ever known. As we pass through the space between these arms, the intensity of galactic radiation decreases accompanied by reduced cloud coverage and increased temperatures. Now, as our planetary system oscillates out of plane, cosmic radiation is reduced even further, pushing up cloud coverage. global clouds reached a minimum, beginning an even hotter period, lasting about 30 million years. Each space between the Milky Way’s arms has its own size but can produce two to three periods this very hot extraplane period during our 50 to 100 million year transit. Farther out in our galaxy’s orbit, galactic radiation increases again as we approach the next cold spiral arm, the Perseus arm, home of the Ordovician ice age 450 million years ago.

However, closer to home, in about 10 thousand years, as the earth’s obliquity begins to move lower, the planet continues to cool. At low obliquity and eccentricity remaining high, we will continue to experience cooling towards the next glacial initiation point – the tipping point – where eccentricity is high and obliquity is low instigated by precession would promote rapid expansion of sea ice, cooling the ice albedo and the next 80 thousand years of ice age.