Reviews of Geophysics, Volume 61, Issue 1. March 2023. Mechanisms and Impacts of Earth System Tipping Elements. Seaver Wang, Adrianna Foster, Elizabeth A. Lenz, John D. Kessler, Julienne C. Stroeve, Liana O. Anderson, Merritt Turetsky, Richard Betts, Sijia Zou, Wei Liu, William R. Boos, Zeke Hausfather. First published: 15 February 2023. [$ to read the full text] “In recent years, discussions of climate change have shown growing interest in “tipping elements” of the Earth system, also imprecisely referred to as “tipping points.” This refers to Earth system components like the tropical rainforests of Amazonia or the Greenland and Antarctic ice sheets which may exhibit large-scale, long-term changes upon reaching critical global warming, greenhouse gas, or other thresholds. Once such thresholds are passed, some tipping elements could in turn produce additional greenhouse gas emissions or change the Earth’s energy balance in ways that moderately reinforce warming. In this review, we summarize the current state of scientific knowledge on 10 systems that some have referred to as potential tipping elements of the climate system. We describe the mechanisms important to each system, highlight the response of these systems to climate change so far, and explain the dynamics of potential future changes that these systems could undergo in response to further climate change. Overall, even considering remaining scientific uncertainties, tipping elements will influence future climate change and may involve major impacts on ecosystems, climate patterns, and the carbon cycle starting later this century. Aggressive efforts to stabilize climate change could significantly reduce such impacts.”

• “we review mechanisms, predictions, impacts + knowledge gaps associated w 10 notable Earth system components proposed to be tipping elements. We evaluate which tipping elements are approaching critical thresholds + whether shifts may manifest rapidly or over longer timescales.”
• We explain the key dynamics at play behind the following candidate tipping elements: – Atlantic Meridional Overturning Circulation – Marine methane hydrate deposits – Greenland + Antarctic ice-sheets – Permafrost soils – Boreal forests – Tropical seasonal monsoons
• Each section is a few pages, describing factors influencing each system, current ongoing changes, potential for tipping behavior, uncertainties, and future projections for change.
• Finally, we collectively synthesize the existing literature on these proposed tipping elements to assess near-term + long-term risks they could pose to the climate system based on positive feedbacks on warming, other climate shifts, and their potential long-term irreversibility.“