This pub-sci insideclimatenews.org/news/13012021/… had me hope it's mere doomism so I read the paper advances.sciencemag.org/content/7/3/ea… It's true. 20yrs of observational data on biome's carbon flux say, due to rising respiration from˚C ALONE, land carbon sink has shrunk already. -20%by 2040 is inevitable
What they tell us is real life stuff, not guesstimates. They describe how they reduced the observational data on carbon flux to temperature-only impact on photosynthesis and respiration –ruling out factors like drought or nutrient availability from messing up their investigation.
The respiration and photosynthesis sensitivity to temperature shows big differences. That's because of 3 types of plants, distinct in their CO2 uptake in source and in their preference for a C-isotope.
C3 plants dominate in mid-high latitudes while C4 plants grow in the tropics.
C3 plants dominate in mid-high latitudes while C4 plants grow in the tropics.
This graph from the new paper by Duffy et al shows photosynthesis and respirational sensitivity to ambient temperature of temperate/boreal C3🟢and tropical C4🟡.
🟢thrive at 18C, our spring an autumn in Global North,
🟡like it hot at 28C.
But respiration increases exponentially!
🟢thrive at 18C, our spring an autumn in Global North,
🟡like it hot at 28C.
But respiration increases exponentially!
The tipping point in ambient temperature, at which plants begin to become a net CO2 source (just from the factor temperature alone!), lies at x many months per year above the temperature threshold, 18/28˚C.
What makes it a "tipping point" is the long-term irreversibility of it.
What makes it a "tipping point" is the long-term irreversibility of it.
Today's ~ 18% loss of terrestrial carbon sink from the factor temperature ALONE are due to 1.2˚C GMT rise from 415ppm CO2 in the atmo.
To get back to ~100% terrestrial carbon sink, ppm would have be < 350ppm.
That's not going to happen.
ppm and˚C are rising.
👉Ecosystems tip.
To get back to ~100% terrestrial carbon sink, ppm would have be < 350ppm.
That's not going to happen.
ppm and˚C are rising.
👉Ecosystems tip.
They tip so much that over the course of a year they become a net CO2 source from respiration alone - without the mid-term chance of changing back to sink.
(And then they die off, bacteria eat, fart or burp, and that too, adds CO2 and N2O to the atmosphere. Not mentioning🔥)
(And then they die off, bacteria eat, fart or burp, and that too, adds CO2 and N2O to the atmosphere. Not mentioning🔥)
So 18˚C or 28˚if you live in the tropics is the new worry point. Not the new record by the end of the year "warmest year on record", or a short heatwave record in mid summer.
No.
How many days above 18˚is the threshold for😱
(Our🇩🇪pre-spring has had 5 days above 18˚ already.)
No.
How many days above 18˚is the threshold for😱
(Our🇩🇪pre-spring has had 5 days above 18˚ already.)
The authors say, the tipping point from temperature ALONE is in the 2040s.
So. If we don't manage to convince a majority of swift & deep decarbonisation, going beyond any so far proposed mile stones in NDC,
in other words, if we don't stay on RCP2.6, then by 2040 we're fucked.
So. If we don't manage to convince a majority of swift & deep decarbonisation, going beyond any so far proposed mile stones in NDC,
in other words, if we don't stay on RCP2.6, then by 2040 we're fucked.
Oh. This
Not ALL biomes become a net source. We lose "only" 30%-50% of global net terrestrial carbon sink, depending how warm we let it get by 2100, if we don't stick to RCP2.6.
https://twitter.com/anlomedad/status/1364120889621680128is wrong, not backed by the paper. Sorry.
Not ALL biomes become a net source. We lose "only" 30%-50% of global net terrestrial carbon sink, depending how warm we let it get by 2100, if we don't stick to RCP2.6.
If we still emit by 2040, at least 5% less CO2 than today is taken up by🌳. Today's uptake capacity is already 18% lower.
At least! Bc the study on observational data focused on˚C impact, only.
To balance that further 5% loss from˚C only, we must increase forest areas by 7.5%?
At least! Bc the study on observational data focused on˚C impact, only.
To balance that further 5% loss from˚C only, we must increase forest areas by 7.5%?
My mechanistic distillation of the paper doesn't reflect its content. The authors don't describe biomes as mere carbon sinks. They also tell of disruptive species die-off and slow replacement by species moving into new climate zones (IF we create green corridors for their seeds!)
My amygdala wants to escape the shocking revelation of fast declining land carbon sink. It's just too much to face - so my amygdala goes into denial mode.😁
My mind OTOH wants to stay on topic, somehow, just not in a paralyzing manner.
So my mind wanders, meanders, remembers...
My mind OTOH wants to stay on topic, somehow, just not in a paralyzing manner.
So my mind wanders, meanders, remembers...
This long, unfinished🧵investigated how comparable past climates are to our experiment today
And my belly doubts that.
https://twitter.com/anlomedad/status/1342745087370006528The reason for that project was: scientists largely agree that, as soon as we stop CO2 (at a reasonable lvl), climate stabilises.
And my belly doubts that.
(But I'll spare us my belly of doubt, right now.)
Pic1 shows the biome spread ~ 3.2million years ago. Pic2 shows no ice on alps and Himalaya (no Arctic sea ice and 1/3 in East-Greenland is covered).
How do seeds or ecosystems spread to new climate zones when there IS ice on🗻?
Pic1 shows the biome spread ~ 3.2million years ago. Pic2 shows no ice on alps and Himalaya (no Arctic sea ice and 1/3 in East-Greenland is covered).
How do seeds or ecosystems spread to new climate zones when there IS ice on🗻?
Eventually, all ice will be gone. At 1.5˚by 2100, 2/3 of the Himalaya's everlasting ice is lost. I don't have the numbers for the Alps, but I assume similar.
But 2100 is too late for Indian/Mediterranean ecosystems to make it up North in their escape of rising temperatures.
But 2100 is too late for Indian/Mediterranean ecosystems to make it up North in their escape of rising temperatures.
If Italian ecosystem, seeds, insects, animals, make it across the high, still icy Alps, at all, Germany's horrible land use rate for single family homes and hence, obscene # of roads, stops them from getting further. Pic1 shows extent of SFH in🇩🇪states
https://twitter.com/anlomedad/status/1363183833026281474
North/North-East of EU is where droughts pile up, where Italian ecosystems need to replace the temperature-threatened biomes. And soon. 2100 is too late by far if humans aim to "use" biomes as carbon sinks, at all. We can plant cypresses - but what other elements wd they require?
And how do those get here?
Occasionally, insects like an Italian mozzie species, piggy-back on cars into South Germany. That's kinda like what a pack of wolves or flock of migratory birds wd do with seeds in their pelts and feathers.
But it takes AGES to accumulate to a biome.
Occasionally, insects like an Italian mozzie species, piggy-back on cars into South Germany. That's kinda like what a pack of wolves or flock of migratory birds wd do with seeds in their pelts and feathers.
But it takes AGES to accumulate to a biome.
(We just had a short, hateful "debate" on reducing single family homes here in G. It's what's needed. #FaceTheClimateEmergency For migration corridors, too. But the entitled, decadent, myopic, hateful politicians AND journalists drove the debate to the ground before it took root)
Anyway. We really gotta provide migration corridors for beings, in addition to artificially ushering in new biomes better suited to survive with productivity in our changing climates.
And we really gotta inform the electorate of this need as reason for stopping single👨👩👧homes &🛣️
And we really gotta inform the electorate of this need as reason for stopping single👨👩👧homes &🛣️
The other weird thought my amygdala preferred over facing the big truths in the paper advances.sciencemag.org/content/7/3/ea… ... the other weird thought was:
does that behaviour of plants emitting more CO2 with rising˚C show in past climate records?
does that behaviour of plants emitting more CO2 with rising˚C show in past climate records?
To find out, how far back in the past to look before plants might have functioned too different to today's C3 and C4 plants?
C4 plants evolved 35Ma, becoming significant only 7-6Ma. But C3 are 240mio yrs old!
(How did C3🌳manage in high˚C from >1000ppm??)
https://twitter.com/anlomedad/status/1364120876468359170
C4 plants evolved 35Ma, becoming significant only 7-6Ma. But C3 are 240mio yrs old!
(How did C3🌳manage in high˚C from >1000ppm??)
So. What to look for: after a warming period to higher than +1.5˚C, a CO2 spike might show from the dominant C3 plants respirating in heat stress.
And does it?
Maybe. Not really.
Grmpf.
Not considering longer than 3Ma, tho. IMO, geography was incomparably different before 3Ma.
And does it?
Maybe. Not really.
Grmpf.
Not considering longer than 3Ma, tho. IMO, geography was incomparably different before 3Ma.
(Source for above graph scilogs.spektrum.de/klimalounge/3-…
The blog is @rahmstorf's. The piece on 3mio years of climate in computer simulation is by his PIK-colleague Matteo Willeit.)
The blog is @rahmstorf's. The piece on 3mio years of climate in computer simulation is by his PIK-colleague Matteo Willeit.)
So why doesn't it show? There's a tiny ˚C and ppm peak in the previous interglacial, I think it's called the Eemian? Too tiny? Or cd it be an instance of what the researchers found in observational data from the past 20years, plants releasing more CO2 under higher temperatures?
That last interglacial lasted 15 thousand years, I think. (Too lazy to look it up, now.) So the tiny peak in˚C and ppm is not so tiny, after all, considering that it lasted some part of 15ky. The cooling right after peaking might just be Milancovic doing his thing, slowed by ppm?
Okay. Yeah. I believe the peak in Eemian is a hint. Plants then did react in the current manner, too.
Except, Milancovic wasn't slowed down like in our experiment, today. So the plants releasing CO2 and peaking˚C by it, were stopped when🌞weakened and glaciers rolled over them.
Except, Milancovic wasn't slowed down like in our experiment, today. So the plants releasing CO2 and peaking˚C by it, were stopped when🌞weakened and glaciers rolled over them.
Which won't happen this time.
Waaaaaaahhhh. My amygdala is back at the study topic. What if? The CO2 pulse just continues, and continues to warm, and thaws 100-200Gt of CO2 in the permafrost, and all on top of OUR CO2 already in the atmosphere?
Waaaaah!
Waaaaaaahhhh. My amygdala is back at the study topic. What if? The CO2 pulse just continues, and continues to warm, and thaws 100-200Gt of CO2 in the permafrost, and all on top of OUR CO2 already in the atmosphere?
Waaaaah!
https://twitter.com/AAAAAGGHHHH/status/1351471781643603970
1 more thing
we also need to balance out the plant-side emitted additional CO2, plus the CO2 from the new🌳
https://twitter.com/anlomedad/status/1364127938548011009As maths dyslexic I can't do the numbers. But there's more to the equation. Not only do we need to add more trees than loss in carbon sinks by 2040,
we also need to balance out the plant-side emitted additional CO2, plus the CO2 from the new🌳
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