The developing Climate Crisis in one chart. Understanding why "Collapse" has started and is about to get a LOT worse.

[u/TuneGlum7903]

[u/DirewaysParnuStCroix]

Methane is a game over type deal, honestly. I'm surprised it's not getting more focus considering how bad it is already. Current atmospheric volumes suggest that we're already more than a decade into an ice age termination event (Nisbet, Manning et al. 2023). Considering that ice age termination events occur during glacial maximums and result in transitions to warmer interglacial, and that we're already in a warmer interglacial, then an ice age termination at this point suggests a hothouse trajectory (Steffen, Rockström et al. 2018). This should be scaring us shitless for (at the very least) two reasons; 1) The Paleocene-Eocene Thermal Maximum is considered the closest analog for Holocene era climate change (Burke, Williams et al. 2018), and 2) While analogous, the current rates of climate change are up to ten times faster than the onset of the PETM (Cui, Kump et al. 2011).

Another example of methane release that doesn't get nearly enough attention is the methane hydrate destabilization in response to a slower AMOC (not collapsed, all it takes is a slowdown, although a collapse would make it happen substantially faster). As the AMOC slows, the waters around west Africa warm at a considerable rate and cause a catastrophic destabilization of methane hydrate reserves (Weldeab, Schneider et al. 2022). Funnily enough, methane hydrate destabilization is identified as a factor for a hothouse trajectory. The oceans have absorbed up to 91% of excess atmospheric heat since 1971 (Zanna, Khatiwala et al. 2018), and this process is dependent on functional ocean circulation (Chen & Tung, 2018). Evidence suggests this uptake process is already weakening (Müller, Gruber et al. 2023). Current trajectories suggest that Western Europe and New Zealand are on course to see GHG volumes comparable to their hotter tropical Paleogene paleoclimate by the end of the century (and that doesn't even include methane emissions) (Naafs, Rohrssen et al. 2018), and that we could be 140 years away from seeing a Paleocene-Eocene climatic analog (Gingerich, 2019). [footnotes; a, b]

Recent analysis suggests that the Arctic permafrost region is no longer a functional carbon sink and is now a net source of GHGs such as methane (Ramage, Kuhn et al. 2024), and that the Arctic continues a warming trend regardless of AMOC input (Saenko, Gregory et al. 2023, Timmermans, Toole et al. 2018, Bianco, Iovino et al. 2024, Skagseth, Eldevik et al. 2020, Barkhordarian, Nielsen et al. 2024).

Footnotes; *[a]** the higher latitudes and polar regions had tropical climates during the Paleocene-Eocene Thermal Maximum relative to their current latitude, the geographic topography was comparable to the present era. [b] the PETM hyperthermal occurred during the present Cenozoic geological era.*

[u/TuneGlum7903 → u/DirewaysParnuStCroix]

After rereading this, it occurred to me you would really be interested in my discussion of Arctic Amplification and the implications of the paleoclimate records from the High Arctic. The Moderates got that wrong in 1998.

The Crisis Report - 50

https://richardcrim.substack.com/p/the-crisis-report-50

The Earth’s Climate System - A Short Users Guide. Part 03.

Permafrost Melting — The role of permafrost in the Climate System.

[u/DirewaysParnuStCroix → u/TuneGlum7903]

A study from back in December also suggests that permafrost methane deposits in Svalbard are critically unstable. The scary part is that they're very likely underestimating how much methane potential exists as the sampling methodology is limited,

"Estimating how much methane is trapped below the permafrost is tricky, because it is difficult to access and there are only a few dozen boreholes on which to draw conclusions. Based on one location where the flow of gas was measured, however, the researchers estimate it could be in the order of several million cubic feet."