(long) 🧵:. • Noted climate physicist personally dives into cost-benefit Integrated Assessment Models (IAM's) - DICE and others. •Writes own simplified version! Derives *intriguing* results!. A 🧵tour exploring his investigation and - slightly provocative? - conclusions!

RT @PatrickTBrown31: When discussing the intersection of climate change and insurance, it is interesting and valuable to observe the differ….

. sink is permanently impaired, simply reducing our positive CO₂ emissions to zero may not be enough to either restore the efficiency of the land sink nor stabilize global surface temps (at least not for multi-decadal timescales past achieving net-zero CO₂ emissions).

. emissions technologies, and seem to be sharing the scary news to scare everybody else straight into reducing emissions to address the problem. And, yes, obviously, we need to reduce our positive emissions (to ~zero) to ultimately stop things getting worse. But *IF* the land.

And I just mention all this again, because many of the people sharing these headlines - e.g., "Major carbon sink may have vanished for a second year in a row!" - don't seem to connect some of these implications. Many of them seem vehemently opposed to even the idea of negative. .

. CO₂ emissions. Which suggests that *if* (again, *if*) the land sink is currently exhibiting signs of being or becoming permanently impaired, then we may not be able to affect its annual net-CO₂-exchange with the atmosphere by just sharply reducing our emissions.🤷.

of the atmospheric stock flowing (net) to the other two pools. So, it is the relative cumulative perturbations of the three stocks that is pacing the annual net exchange of CO₂ (as well as associated temperature, physiological effects, etc.), and *NOT* primarily annual human. .

But what's closer to the actual dynamics is something more like this👇. Virtually all of our annual emissions get added to the atmospheric stock of CO₂. Separately, *net* exchange of gas btwn the atmosphere stock of CO₂ and land and ocean carbon pools results in ~1% of.

And a final point I'll repeat from last year:. I think a lot of people have a mental model that has them "understanding" that it is our annual ~40 GtCO₂ yr⁻¹ emissions that get (net) partioned/taken up by the sinks. Similar to what seems to be conveyed by a schematic like👇.

Because of this uncertainty, the authors note:. "Planning for net negative global CO₂ emissions remains important, given the chance of global temperatures overshooting 1.5°C, along with research to better understand the emissions consistent with warming stabilization.". And a. .

And a large part of the uncertainty - as reflected in this large 5ᵗʰ to 95ᵗʰ percentile range - is due to uncertainty regarding the carbon cycle, and specifically the land sink👇. (from Jenkins, et al. above).

. reduced emissions]. Which implies, for instance, that there is a about a 5% chance that we will need to achieve *𝙣𝙚𝙩-𝙣𝙚𝙜𝙖𝙩𝙞𝙫𝙚* emissions of 7.3 GtCO₂ yr⁻¹ simply to halt temp increase/stabilize surface temps (i.e., not for reducing temps but just to *stabilize*).

The best estimates (such as above👆) are for 5ᵗʰ-95ᵗʰ percentile ranges of "CO₂ emissions consistent with halting anthropogenic warming over multi-decadal timescales span −7.3 to +6.2 GtCO₂/yr" [with further variability depending on the temperature threshold and pathway to.

. global surface temps. I say "odds" because it is *already* the case that we don't know (and can't know) exactly the level of net-positive or net-zero or net-negative CO₂ emissions that will be req'd.👇. [New Scientist url: .

I made a similar observation last time this made the rounds (2024?), but since I again don't see anyone make the inference:. *If* this is some fundamental regime shift in land sink carbon cycle dynamics - *IF! * - then odds shift to net-zero CO₂ not being sufficient to stabilize

RT @lrntex: Adaptation Insight from a corn seed industry insider on the 'stack.

RT @wang_seaver: Great explainer by my colleagues @lrntex @atrembath on the buzzy Nature paper from mid-June--a case of author/journal scie….

RT @PatrickTBrown31: “This sounds not great until you remember that background yield trends are very great.”. Also great is this entire ana….

check that - the Kindle Paperwhite can't do assistive reading of the book. but you can use Adobe for reading aloud, and various AI's with the pdf directly.

quite a few books like this offered at steep discounts to the Kindle versions. and I just emailed the pdf for the first book to my Kindle Paperwhite, and the reading experience is just like a Kindle book.🤷.