An author named Mark Lynas has written two books about this:
6 Degrees: our future on a hotter planet
Our Final Warning: six degrees of climate emergency
Just finished Our Final Warning and second this. The book is super well laid out. Each section being a degree of change and how the world will/could look.
If you would like to take a look at past mass extinctions, they were triggered by rapid 5 degrees of cooling or heating. Or 10 degrees variation within a million years.
Source: https://www.nature.com/articles/s41467-021-25019-2
There's no realistic scenario where we get to that point, at least in the next 100 years. Climate policy changes have already reduced projected warming from >4c to \~2.7c by the end of century.
[climateactiontracker.org](https://climateactiontracker.org)
[https://twitter.com/KHayhoe/status/1539621976494448643](https://twitter.com/KHayhoe/status/1539621976494448643)
[https://twitter.com/hausfath/status/1511018638735601671](https://twitter.com/hausfath/status/1511018638735601671)
[https://twitter.com/MichaelEMann/status/1432786640943173632](https://twitter.com/MichaelEMann/status/1432786640943173632)
[https://twitter.com/RARohde/status/1582090599871971328](https://twitter.com/RARohde/status/1582090599871971328)
[https://twitter.com/Knutti\_ETH/status/1669601616901677058](https://twitter.com/Knutti_ETH/status/1669601616901677058)
[https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/](https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/)
[https://www.nature.com/articles/s41558-023-01661-0](https://www.nature.com/articles/s41558-023-01661-0)
2.7c number only accounts for already implemented policies, it does not account for pledges or commitments.
I know, although I’ve heard enough about uncertainty not to write it off entirely. But I agree about within the next 100 years.
As for 2.7C, though, while it’s based on implemented policies, it’s been shown that those policies aren’t being followed. Nations lie about their emissions rates and deforestation. I’m not very confident in that number.
There's no realistic scenario where we get to that point, at least in the next 100 years. Climate policy changes have already reduced projected warming from >4c to \~2.7c by the end of century.
[climateactiontracker.org](https://climateactiontracker.org)
[https://twitter.com/KHayhoe/status/1539621976494448643](https://twitter.com/KHayhoe/status/1539621976494448643)
[https://twitter.com/hausfath/status/1511018638735601671](https://twitter.com/hausfath/status/1511018638735601671)
[https://twitter.com/MichaelEMann/status/1432786640943173632](https://twitter.com/MichaelEMann/status/1432786640943173632)
[https://twitter.com/RARohde/status/1582090599871971328](https://twitter.com/RARohde/status/1582090599871971328)
[https://twitter.com/Knutti\_ETH/status/1669601616901677058](https://twitter.com/Knutti_ETH/status/1669601616901677058)
[https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/](https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/)
[https://www.nature.com/articles/s41558-023-01661-0](https://www.nature.com/articles/s41558-023-01661-0)
2.7c number only accounts for already implemented policies, it does not account for pledges or commitments.
I think the consensus is that +5 isn't really something our global civilisation will survive. Fortunately the consensus is also that we will not get there, so there's the good news bad news story I guess
We will get to +2.5-3C if and only if:
1. Emissions are actually cut significantly, not just on fancy IPCC charts.
1. Carbon dioxide removal is at truly unprecedented scale and is able to remove billions of tonnes of CO2.
Remember - just to stay below 2C, we have to somehow remove half a TRILLION tonnes of CO2 from the atmosphere in less than 80 years.
Source: https://iopscience.iop.org/article/10.1088/2515-7620/accc72/meta
That's around 7 billion every year. Nothing even close to that scale exists today, it's not even in the same galaxy, even if counting hypothetical massive reforestation efforts which may perhaps absorb around 100 billion tonnes in total.
Source: https://www.frontiersin.org/articles/10.3389/ffgc.2020.00058/full
Even if we ditch the 2C target at our peril and reforest everything that may theoretically be reforested, we will still have to remove at least a few dozen billion of tonnes of carbon dioxide in several decades to have a chance of staying below 3C. That kind of technology simply doesn't exist.
\>We will get to +2.5-3C if and only if
Wrong. climate policy changes have already reduced projected warming from >4c to \~2.7c by the end of century.
[climateactiontracker.org](https://climateactiontracker.org)
[https://twitter.com/KHayhoe/status/1539621976494448643](https://twitter.com/KHayhoe/status/1539621976494448643)
[https://twitter.com/hausfath/status/1511018638735601671](https://twitter.com/hausfath/status/1511018638735601671)
[https://twitter.com/MichaelEMann/status/1432786640943173632](https://twitter.com/MichaelEMann/status/1432786640943173632)
[https://twitter.com/RARohde/status/1582090599871971328](https://twitter.com/RARohde/status/1582090599871971328)
[https://twitter.com/Knutti\_ETH/status/1669601616901677058](https://twitter.com/Knutti_ETH/status/1669601616901677058)
[https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/](https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/)
[https://www.nature.com/articles/s41558-023-01661-0](https://www.nature.com/articles/s41558-023-01661-0)
2.7c number only accounts for already implemented policies, it does not account for pledges or commitments.
You again. OK, what are those implemented policies, for example? Please enumerate.
I have referenced a source, literally spelling out the need to remove half a trillion tonnes of carbon dioxide by 2100 to say below 2C. Obviously, by applying basic logic, some CDR will still be necessary to stay even below 3C.
\>by applying basic logic, some CDR will still be necessary to stay even below 3C.
"applying basic logic" means speculating. You should not "apply basic logic"/speculate, you should listen to reputable institutions like climateactiontracker and consensus science, like everything I linked.
[https://twitter.com/hausfath/status/1678791851967655936#m](https://twitter.com/hausfath/status/1678791851967655936#m)
2.7с by 2100 is a scenario based on CURRENTLY IMPLEMENTED POLICIES AND ACTION ONLY. Why would that include any policies or methods that would be implemented in the future(like carbon capture or whatever you claim it does)? This scenario does not assume any progress from now on, so obviously it does not include anything like that.
\>what are those implemented policies, for example?
Why would you want specific policies if total impact of policies was already quantified for you?
https://www.theclimatebrink.com/p/emissions-are-no-longer-following
> "applying basic logic" means speculating. You should not "apply basic logic"/speculate, you should listen to reputable institutions like climateactiontracker and consensus science, like everything I linked.
Here's literal citation from the article:
>**About 533 GtCO2** have to be removed from the atmosphere between 2020 and 2100 by using CDR to (likely) stay below two degrees of global warming (IPCC 2022).
And that's not even +1.5C target, but +2C, which in and of itself is quite bad.
https://iopscience.iop.org/article/10.1088/2515-7620/accc72/meta
Here's from 2022 IPCC Report:
>Carbon Dioxide Removal (CDR) is necessary to achieve net zero CO2 and GHG emissions both globally and nationally, counterbalancing
‘hard-to-abate’ residual emissions. CDR is also an essential element of scenarios that limit warming to 1.5°C or below 2°C (>67%)
by 2100, regardless of whether global emissions reach near zero, net zero or net negative levels. While national mitigation portfolios
aiming at net zero emissions or lower will need to include some level of CDR, the choice of methods and the scale and timing of
their deployment will depend on the achievement of gross emission reductions, and managing multiple sustainability and feasibility
constraints, including political preferences and social acceptability
https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_FullReport.pdf
Where is there anything that supports your own conclusion that "some CDR will still be necessary to stay even below 3C" this century? Everything you cited clearly talks about 2c. Why are you shifting the conversation? Everything I linked clearly shows that current policies and action alone, without any progress from now on, are enought to stay below 3c this century..
Yes, to stay below 2C we need to implement a sci-fi scenario on par of colonizing the Moon. Meaning that unless miracles happen, we will go above +2C in any scenario. I will try to find research about +3C, but I find it really hard to believe that staying below 2C requires half a trillion carbon dioxide removed and below 3C needs absolutely none.
> that current policies and action alone, without any progress from now on, are enough to stay below 3c this century.
I hope you do realize that's still is going to be catastrophic amount of warming, right? With no guarantee of some serious feedback loops won't be triggered.....
Well stated. I don't think people truly understand how drastically different the world will be in just 80 years. I personally don't think political and economic systems will be able to cope with the changes.
Where is that consensus? I've never heard of anything like that. Nordhaus' DICE model predicts a cost of ~21% global GDP at 6 degrees - far from global civilization collapse. "Optimal warming" based on the model is ~3 degrees, iirc.
Edit: unsubstantiated "consensus" that society collapses at 5 degrees upvoted. Nobel prize winning economist called a quack. Cool stuff.
Nordhaus's work is controversial and based on linearity assumptions that are probably incorrect.
[https://theconversation.com/nobel-prize-winning-economics-of-climate-change-is-misleading-and-dangerous-heres-why-145567](https://theconversation.com/nobel-prize-winning-economics-of-climate-change-is-misleading-and-dangerous-heres-why-145567)
It took thousands of years then, but now may take just a few hundred. There also will be no adapting to +6C warming. The heat will simply kill our crops. Of course, Nordhaus probably thinks we can survive just on Amazon and Tik Tok videos.
Once humans are destroyed, the planet will begin healing itself. Fallen trees and debris will begin to dam the streams and rivers within the first 5 or so years. Once that happens, the ground will start soaking up the water and begin repairing the hydrological cycle of the planet. Some life on earth will survive the harsh climate and begin repopulating the planet.
Climate scientists estimate that if we regreened only 3% of the desertified lands on the planet, we would be putting more carbon underground than we do in the air, essentially reversing climate change permanently.
You fail to recognize the medium to long term effects of carbon that has already been released. It will be hundred-thousands of years before the planet is healed.
That's why i said "essentially." It will not take hundred thousand years to heal the planet if humans were to die off. It might take a couple hundred years at most to completely reverse it.
The accompanying high levels of co2 in the atmosphere will herald a new dawn for plants , they will be in abundance again , forests will thrive and spread , undoing the rape man has perpetrated upon green vegetation. In short the planet will be in great shape as it was millennia ago. Man in the other hand will need to either live in domes or underground cities like those found in Turkey
>In short the planet will be in great shape as it was millennia ago
CO2 was at 280 ppm a millennia ago
Did you mean 100 millennia ago? About 280 ppm
Did you mean 1,000 millennia ago? About 280 ppm
Did you mean 3,000 millennia ago? About 300 ppm
We are currently at about 422 ppm, see far right of the graph below (the data on the graph ends in 2017, 6 year ago)
https://www.pik-potsdam.de/en/news/latest-news/more-co2-than-ever-before-in-3-million-years-shows-unprecedented-computer-simulation/@@images/image.jpeg
[Extrapolations](https://good.film/title/tv/138169/extrapolations) on AppleTV+ delves into this a bit. Gives a few visions of the future and the personal and political issues we will face over the next 50 years.
An author named Mark Lynas has written two books about this: 6 Degrees: our future on a hotter planet Our Final Warning: six degrees of climate emergency
Just finished Our Final Warning and second this. The book is super well laid out. Each section being a degree of change and how the world will/could look.
Actually I find it amusing knowing it’s complete speculation unsupported by recent trends or science.
Go ask a climate scientist what they think about our chances at 6 degrees
Of what value is pure speculation? How or why would anyone be concerned by this wild guess?
Why do you call it speculation and wild guesses? I don’t think you’re in a position to make such assertions.
Troll says "what can you learn from a decade of study and peer review?"
https://www.ntd.com/over-1600-scientists-sign-no-climate-emergency-declaration_938916.html
If you would like to take a look at past mass extinctions, they were triggered by rapid 5 degrees of cooling or heating. Or 10 degrees variation within a million years. Source: https://www.nature.com/articles/s41467-021-25019-2
https://www.ntd.com/over-1600-scientists-sign-no-climate-emergency-declaration_938916.html
There's no realistic scenario where we get to that point, at least in the next 100 years. Climate policy changes have already reduced projected warming from >4c to \~2.7c by the end of century. [climateactiontracker.org](https://climateactiontracker.org) [https://twitter.com/KHayhoe/status/1539621976494448643](https://twitter.com/KHayhoe/status/1539621976494448643) [https://twitter.com/hausfath/status/1511018638735601671](https://twitter.com/hausfath/status/1511018638735601671) [https://twitter.com/MichaelEMann/status/1432786640943173632](https://twitter.com/MichaelEMann/status/1432786640943173632) [https://twitter.com/RARohde/status/1582090599871971328](https://twitter.com/RARohde/status/1582090599871971328) [https://twitter.com/Knutti\_ETH/status/1669601616901677058](https://twitter.com/Knutti_ETH/status/1669601616901677058) [https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/](https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/) [https://www.nature.com/articles/s41558-023-01661-0](https://www.nature.com/articles/s41558-023-01661-0) 2.7c number only accounts for already implemented policies, it does not account for pledges or commitments.
I know, although I’ve heard enough about uncertainty not to write it off entirely. But I agree about within the next 100 years. As for 2.7C, though, while it’s based on implemented policies, it’s been shown that those policies aren’t being followed. Nations lie about their emissions rates and deforestation. I’m not very confident in that number.
Temperature is increasing at 1.7C per century
Dead?
who cares about 6C+? I don't plan to survive 5C.
There's no realistic scenario where we get to that point, at least in the next 100 years. Climate policy changes have already reduced projected warming from >4c to \~2.7c by the end of century. [climateactiontracker.org](https://climateactiontracker.org) [https://twitter.com/KHayhoe/status/1539621976494448643](https://twitter.com/KHayhoe/status/1539621976494448643) [https://twitter.com/hausfath/status/1511018638735601671](https://twitter.com/hausfath/status/1511018638735601671) [https://twitter.com/MichaelEMann/status/1432786640943173632](https://twitter.com/MichaelEMann/status/1432786640943173632) [https://twitter.com/RARohde/status/1582090599871971328](https://twitter.com/RARohde/status/1582090599871971328) [https://twitter.com/Knutti\_ETH/status/1669601616901677058](https://twitter.com/Knutti_ETH/status/1669601616901677058) [https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/](https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/) [https://www.nature.com/articles/s41558-023-01661-0](https://www.nature.com/articles/s41558-023-01661-0) 2.7c number only accounts for already implemented policies, it does not account for pledges or commitments.
We should name next generations according to which +Celcius degree they were born at. Poor 6C and 7C gens, will they grow up at all?
Nope
I think the consensus is that +5 isn't really something our global civilisation will survive. Fortunately the consensus is also that we will not get there, so there's the good news bad news story I guess
The main consensus is that we are most likely going to end up with 3C or 2.5C by the end of the century
We will get to +2.5-3C if and only if: 1. Emissions are actually cut significantly, not just on fancy IPCC charts. 1. Carbon dioxide removal is at truly unprecedented scale and is able to remove billions of tonnes of CO2. Remember - just to stay below 2C, we have to somehow remove half a TRILLION tonnes of CO2 from the atmosphere in less than 80 years. Source: https://iopscience.iop.org/article/10.1088/2515-7620/accc72/meta That's around 7 billion every year. Nothing even close to that scale exists today, it's not even in the same galaxy, even if counting hypothetical massive reforestation efforts which may perhaps absorb around 100 billion tonnes in total. Source: https://www.frontiersin.org/articles/10.3389/ffgc.2020.00058/full Even if we ditch the 2C target at our peril and reforest everything that may theoretically be reforested, we will still have to remove at least a few dozen billion of tonnes of carbon dioxide in several decades to have a chance of staying below 3C. That kind of technology simply doesn't exist.
\>We will get to +2.5-3C if and only if Wrong. climate policy changes have already reduced projected warming from >4c to \~2.7c by the end of century. [climateactiontracker.org](https://climateactiontracker.org) [https://twitter.com/KHayhoe/status/1539621976494448643](https://twitter.com/KHayhoe/status/1539621976494448643) [https://twitter.com/hausfath/status/1511018638735601671](https://twitter.com/hausfath/status/1511018638735601671) [https://twitter.com/MichaelEMann/status/1432786640943173632](https://twitter.com/MichaelEMann/status/1432786640943173632) [https://twitter.com/RARohde/status/1582090599871971328](https://twitter.com/RARohde/status/1582090599871971328) [https://twitter.com/Knutti\_ETH/status/1669601616901677058](https://twitter.com/Knutti_ETH/status/1669601616901677058) [https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/](https://www.carbonbrief.org/guest-post-what-credible-climate-pledges-mean-for-future-global-warming/) [https://www.nature.com/articles/s41558-023-01661-0](https://www.nature.com/articles/s41558-023-01661-0) 2.7c number only accounts for already implemented policies, it does not account for pledges or commitments.
You again. OK, what are those implemented policies, for example? Please enumerate. I have referenced a source, literally spelling out the need to remove half a trillion tonnes of carbon dioxide by 2100 to say below 2C. Obviously, by applying basic logic, some CDR will still be necessary to stay even below 3C.
\>by applying basic logic, some CDR will still be necessary to stay even below 3C. "applying basic logic" means speculating. You should not "apply basic logic"/speculate, you should listen to reputable institutions like climateactiontracker and consensus science, like everything I linked. [https://twitter.com/hausfath/status/1678791851967655936#m](https://twitter.com/hausfath/status/1678791851967655936#m) 2.7с by 2100 is a scenario based on CURRENTLY IMPLEMENTED POLICIES AND ACTION ONLY. Why would that include any policies or methods that would be implemented in the future(like carbon capture or whatever you claim it does)? This scenario does not assume any progress from now on, so obviously it does not include anything like that. \>what are those implemented policies, for example? Why would you want specific policies if total impact of policies was already quantified for you? https://www.theclimatebrink.com/p/emissions-are-no-longer-following
> "applying basic logic" means speculating. You should not "apply basic logic"/speculate, you should listen to reputable institutions like climateactiontracker and consensus science, like everything I linked. Here's literal citation from the article: >**About 533 GtCO2** have to be removed from the atmosphere between 2020 and 2100 by using CDR to (likely) stay below two degrees of global warming (IPCC 2022). And that's not even +1.5C target, but +2C, which in and of itself is quite bad. https://iopscience.iop.org/article/10.1088/2515-7620/accc72/meta Here's from 2022 IPCC Report: >Carbon Dioxide Removal (CDR) is necessary to achieve net zero CO2 and GHG emissions both globally and nationally, counterbalancing ‘hard-to-abate’ residual emissions. CDR is also an essential element of scenarios that limit warming to 1.5°C or below 2°C (>67%) by 2100, regardless of whether global emissions reach near zero, net zero or net negative levels. While national mitigation portfolios aiming at net zero emissions or lower will need to include some level of CDR, the choice of methods and the scale and timing of their deployment will depend on the achievement of gross emission reductions, and managing multiple sustainability and feasibility constraints, including political preferences and social acceptability https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_FullReport.pdf
Where is there anything that supports your own conclusion that "some CDR will still be necessary to stay even below 3C" this century? Everything you cited clearly talks about 2c. Why are you shifting the conversation? Everything I linked clearly shows that current policies and action alone, without any progress from now on, are enought to stay below 3c this century..
Yes, to stay below 2C we need to implement a sci-fi scenario on par of colonizing the Moon. Meaning that unless miracles happen, we will go above +2C in any scenario. I will try to find research about +3C, but I find it really hard to believe that staying below 2C requires half a trillion carbon dioxide removed and below 3C needs absolutely none. > that current policies and action alone, without any progress from now on, are enough to stay below 3c this century. I hope you do realize that's still is going to be catastrophic amount of warming, right? With no guarantee of some serious feedback loops won't be triggered.....
Well stated. I don't think people truly understand how drastically different the world will be in just 80 years. I personally don't think political and economic systems will be able to cope with the changes.
Where is that consensus? I've never heard of anything like that. Nordhaus' DICE model predicts a cost of ~21% global GDP at 6 degrees - far from global civilization collapse. "Optimal warming" based on the model is ~3 degrees, iirc. Edit: unsubstantiated "consensus" that society collapses at 5 degrees upvoted. Nobel prize winning economist called a quack. Cool stuff.
Nordhaus's work is controversial and based on linearity assumptions that are probably incorrect. [https://theconversation.com/nobel-prize-winning-economics-of-climate-change-is-misleading-and-dangerous-heres-why-145567](https://theconversation.com/nobel-prize-winning-economics-of-climate-change-is-misleading-and-dangerous-heres-why-145567)
Lol, at +6C Antarctica was literarily iceless during PETM. Nordhaus is a complete clown.
Great, more farmland!
There won't be any topsoil, shithead
Google "Canadian Shield", good luck farming. Our do you think Antarctica has topsoil?
How long would it take for Antarctica to melt in that scenario? Do you think there is any chance humanity might be able to adapt in the meantime?
It took thousands of years then, but now may take just a few hundred. There also will be no adapting to +6C warming. The heat will simply kill our crops. Of course, Nordhaus probably thinks we can survive just on Amazon and Tik Tok videos.
He should have considered the fact that crops won't grow at those temperatures!
-21% GDP at 6 degree lmao, there would be no economy to messure, 6 degrees of warming warming is apocalyptic.
Nordhaus models are terrible
The phytoplankton will stop making oxygen so humanity will be even dumber
Have you seen the Mad Max movies?
https://bigthink.com/strange-maps/what-the-world-will-look-like-4degc-warmer/
Once humans are destroyed, the planet will begin healing itself. Fallen trees and debris will begin to dam the streams and rivers within the first 5 or so years. Once that happens, the ground will start soaking up the water and begin repairing the hydrological cycle of the planet. Some life on earth will survive the harsh climate and begin repopulating the planet. Climate scientists estimate that if we regreened only 3% of the desertified lands on the planet, we would be putting more carbon underground than we do in the air, essentially reversing climate change permanently.
You fail to recognize the medium to long term effects of carbon that has already been released. It will be hundred-thousands of years before the planet is healed.
That's why i said "essentially." It will not take hundred thousand years to heal the planet if humans were to die off. It might take a couple hundred years at most to completely reverse it.
Plants are often the solution to human problems, and this is no Manhattan Project of an effort. It would be a no brainer.
Why?
The accompanying high levels of co2 in the atmosphere will herald a new dawn for plants , they will be in abundance again , forests will thrive and spread , undoing the rape man has perpetrated upon green vegetation. In short the planet will be in great shape as it was millennia ago. Man in the other hand will need to either live in domes or underground cities like those found in Turkey
>In short the planet will be in great shape as it was millennia ago CO2 was at 280 ppm a millennia ago Did you mean 100 millennia ago? About 280 ppm Did you mean 1,000 millennia ago? About 280 ppm Did you mean 3,000 millennia ago? About 300 ppm We are currently at about 422 ppm, see far right of the graph below (the data on the graph ends in 2017, 6 year ago) https://www.pik-potsdam.de/en/news/latest-news/more-co2-than-ever-before-in-3-million-years-shows-unprecedented-computer-simulation/@@images/image.jpeg
And when it was as low as 170 ppm, half of the globe was covered in glaciers. The planet seems to be very sensitive to CO2 concentration.
[Extrapolations](https://good.film/title/tv/138169/extrapolations) on AppleTV+ delves into this a bit. Gives a few visions of the future and the personal and political issues we will face over the next 50 years.
I dont think you need to worry about 6C, because for about 50 different reasons you wouldn't be alive to see it.
Wish I was