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Amplifying feedbacks leading to accelerated planetary temperatures by Andrew Glikson “The paleoclimate record shouts to us that, far from being self-stabilizing, the Earth's climate system is an ornery beast which overreacts even to small nudges” (Wally Broecker) Many climate change models, including by the IPCC , appear to minimize or even neglect the amplifying feedbacks of global warming, which are pushing temperatures upward in a runaway chain reaction-like process, as projected by Wally Broecker and other : Lateral and vertical ice melt, including formation of water films on ice;  Reduced CO2 intake by the warming oceans due to warming. Currently the oceans absorb between 35-42 percent of all CO2 emitted into the atmosphere and around 90 percent of the excess heat from the rise in greenhouse gases; Warming, desiccation, deforestation and fires over land areas ; Release of methane from permafrost and polar sediments; These feedbacks drive a chain reaction of events, accel...

The fatal road to +4°Celsius Extreme GHG and T°C rise rates exceed climate tipping thresholds Andrew Glikson Precis Global CO₂ rise and warming rates have reached a large factor to an order of magnitude higher than those of the past geological and mass extinction events, with major implications for the shift in climate zones and the nature and speed of current extreme weather events. Given the abrupt change in state of the atmosphere-ocean-cryosphere-land system, accelerating since the mid-20ᵗʰ century, the terms climate change and global warming no longer reflect the nature of the climate extremes consequent on this shift. Further to NASA’s reported mean land-ocean temperature rise to +1.18°C for March 2020, relative to the 1951-1980 baseline, large parts of the continents, including Siberia, central Asia, Canada, parts of west Africa, eastern South America and Australia are warming toward mean temperatures of +2°C and higher. The rate exceeds that of the Last Glacial Termination (L...

by Andrew Glikson Earth and climate scientist Australian National University Figure 1.  Relations between CO₂ levels in the atmosphere and mass extinctions of genera. Data cited from  D. Royer et al. (2002) , from  G. Keller (2016)  and  P. Wignall et al. (2002) . Carbon, the essential element underpinning photosynthesis and life, is transformed into toxic substances in the remnants of plants and organisms buried in sediments. Once released to the atmosphere in the form of CO₂, CO and methane, in large quantities these gases become lethal and have been responsible for  mass extinctions of species  (Fig. 1). Figure 2. Potential heating, Carana (2019) Given amplifying feedbacks from land and oceans triggered by rising temperatures, the concept of an upper limit of warming determined by limitation on carbon emissions alone is unlikely, since, under a rising high greenhouse gas concentration, amplifying feedbacks triggered by methane release, bushfires, w...

The changing face of planet Earth Andrew Glikson Earth and Climate scientist Australian National University 12-8-2019 Preamble The inhabitants of planet Earth are in the process of destroying the habitability of their world through the perpetration of the largest mass extinction of species since 66 million years ago, when a large asteroid impacted Earth, and 55 million years since the Paleocene-Eocene Thermal Maximum ( PETM ) reaching 5–8°C. The late Holocene-Anthropocene climate change represents an unprecedented event, triggering a fast shift in climate zones and a series of extreme weather events, with consequences for much of nature and civilization. The changes are manifest where green forests are blackened by fire, droughts are turning grassy planes to brown semi-deserts, brilliant white snow and ice caps are melting into pale blue water and clear blue skies turn grey due to aerosols and jet contrails, most particularly in the northern hemisphere. Unless effective efforts are u...