BurnerAcc2020 t1_j8maaiv wrote
Reply to comment by SaxManSteve in New study shows Acceleration of global sea level rise imminent past 1.8℃ planetary warming by 9273629397759992
> which only speeds up the process of system wide ecological collapse that will absolutely lead to dramatic population contraction in the near future.
Not according to even the scientists who otherwise agree that the future would be "ghastly", though?
https://www.frontiersin.org/articles/10.3389/fcosc.2020.615419/full > It is therefore also inevitable that aggregate consumption will increase at least into the near future, especially as affluence and population continue to grow in tandem (Wiedmann et al., 2020). Even if major catastrophes occur during this interval, they would unlikely affect the population trajectory until well into the 22nd Century (Bradshaw and Brook, 2014). Although population-connected climate change (Wynes and Nicholas, 2017) will worsen human mortality (Mora et al., 2017; Parks et al., 2020), morbidity (Patz et al., 2005; Díaz et al., 2006; Peng et al., 2011), development (Barreca and Schaller, 2020), cognition (Jacobson et al., 2019), agricultural yields (Verdin et al., 2005; Schmidhuber and Tubiello, 2007; Brown and Funk, 2008; Gaupp et al., 2020), and conflicts (Boas, 2015), there is no way—ethically or otherwise (barring extreme and unprecedented increases in human mortality)—to avoid rising human numbers and the accompanying overconsumption. That said, instituting human-rights policies to lower fertility and reining in consumption patterns could diminish the impacts of these phenomena (Rees, 2020).
Not to mention the more mainstream views like those of the IPCC (look at their population graphs).
SaxManSteve t1_j8mfa2n wrote
IPCC population projection models are often criticized for having simple assumptions. They generally model predicted population based on the expected rate of world GDP growth and the correlated predicted reduction in birth rates. They don't use a system dynamics based model, that could model the complexities of overshoot and climate change and its impacts on population. For example global warming will have varying levels of cascading non-linear effects on extreme weather events, things like increases in economic inequality, increase in domestic and international conflict, increase in state fragility, increase in pandemics, increase in population displacement and migration, decrease in ecological biodiversity, decrease in food, fuel, and water resources, increase in droughts and desertification of fertile land, increased fragility of global supply chains, ect..... None of these factors are part of the IPCC models, meaning that their predictions shouldn't be taken as realistic predictions of populations. Rather they should be seen as models that predict population numbers in a world where climate change and overshoot will have little to no impact on human civilization in the near future.
It's also no secret within academic climate science circles that the IPCC has long been politically motivated to underestimate the scale of the problem. Which is why very few climate scientists actually believe that the Paris Accord is realistic. We all know there is no chance the world can avoid 1.5 C mean global warming and that we will likely see a potentially disastrous 2 C increase by 2050. Many already assume that there will be no remaining carbon budget even for the 2 C target
The IPCC infamously fails to account for carbon cycle feedbacks and their associated tipping points when setting their own emissions targets. Meaning that even a 2C warming may well trigger irreversible runaway “hothouse Earth” conditions. In coming years, we will see an ice-free Arctic Ocean, more rapidly melting permafrost, methane releases, an increase in wildfires, and other short-term positive feedbacks that will put climate change on steroids.
Even in the best case, the world can expect more and longer heat waves and droughts, more violent tropical storms, extended wild-fire seasons, accelerating desertification, water shortages, crippled agriculture, food shortages, rising sea levels, and broken supply lines. Coastal cities will be flooded and some may eventually be abandoned. Many other cities are likely to be cut off from food-lands, energy, and other essential resources with the breakdown of national highway and marine transportation networks; this alone would make urban life untenable. According to the recent Environmental Risk Outlook 2021 (2021), at least 414 cities with a total 1.4 billion plus inhabitants, are at high or extreme risk from a combination of pollution, dwindling water supplies, extreme heat stress, and other dimensions of climate change.
From this perspective, it's absurd to even entertain the idea that adding 2+ billion more people on the planet in the next 20 years would be a good idea. We should be currently engaging in an international effort to reduce our current consumption, reduce our energy demand, reduce our birth rates, reduce economic inequality, and ultimately start to move away from a growth for the sake of growth economic model towards an ecologically sustainable economic system.
It's simply immoral and reckless to keep chugging along with the business as usual economic model. Doing so is to condemn billions of people to a brutish, painful and short life.
BurnerAcc2020 t1_j8rc44f wrote
So, my original response got eaten by reddit's spam filter (probably because I included the same link twice, but you'll never know with these things) and I'm going to have to try again, for posterity.
By now, many of the points I made in that comment were already made by others, like Spratt & Dunlop possessing very limited credibility, or that feedbacks are both slow enough relative to human emissions to operate over many centuries and are already accounted for in the IPCC reports to a great extent. In fact, even IPCC report #4 - which was first published in 2007 - already had a whole chapter on carbon cycle and other feedbacks.
https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter7-1.pdf
The feedbacks which are more difficult to account for, like permafrost, still have an impact that's a fraction of human emissions.
I would simply like to reiterate the points around "crippled agriculture, food shortages", etc. It would appear true if you just look at the climate projections and assume that they'll apply to the current amount of land used to grow food. What that assumption misses is that the amount of land won't stay the same: the IPCC assumes that as the population grows and climate change accelerate, people will simply clear-cut down more, more and more forest to the tune of hundreds of millions of hectares and grow crops on that land. Compare the population/GDP graph from my earlier comment (not linking it again in case it also triggers the bot) with the land use graph, where cropland extent and forested land extent simply go in opposite directions in each scenario - to the point where a scenario with 12 billion people cuts down nearly 600 million hectares. This is also why food supply projections for 2050 look like this and like this, and not like what most people assume when only looking at yield reduction projections or the talk of instability.
And finally, yes, we should move to a non-growth and sustainable system. The thing is, it looks like we may well get away with not doing that in this century, even if the cost will simply be paid by the ecosystems and future generation. That is the position of the scientists who collectively wrote the "ghastly future" paper, and at this point, the counterarguments (whether optimistic or the opposite) appear increasingly strained.
Gemini884 t1_j8ns09o wrote
>The IPCC infamously fails to account for carbon cycle feedbacks and their associated tipping points when setting their own emissions targets.
Then why are climate models used in previous IPCC reports so accurate and have predicted the pace of warming so well? Observed warming tends to track middle-of-the-range estimates from previous IPCC reports.
https://www.realclimate.org/index.php/archives/2022/02/another-dot-on-the-graphs-part-ii/
You probably should listen to what actual climate scientists say on the matter-
https://nitter.kavin.rocks/hausfath/status/1557421984484495362
https://nitter.kavin.rocks/hausfath/status/1491134605390352388
https://nitter.kavin.rocks/JoeriRogelj/status/1424743837277294603
https://nitter.kavin.rocks/PFriedling/status/1557705737446592512
https://nitter.kavin.rocks/ClimateAdam/status/1429730044776157185
https://nitter.kavin.rocks/Knutti\_ETH/status/1554473710404485120
https://nitter.kavin.rocks/ClimateOfGavin/status/1556735212083712002#m
There were some models for the recent ipcc report that overestimate future warming and they were included too
https://www.nature.com/articles/d41586-022-01192-2
​
There is no evidence for projected warming <3-4C of any tipping points that significantly change the warming trajectory. Read ipcc report and read what climate scientists say instead of speculating:
https://nitter.kavin.rocks/MichaelEMann/status/1495438146905026563
https://nitter.kavin.rocks/hausfath/status/1571146283582365697#m
"Some people will look at this and go, ‘well, if we’re going to hit tipping points at 1.5°C, then it’s game over’. But we’re saying they would lock in some really unpleasant impacts for a very long time, but they don’t cause runaway global warming."- Quote from Dr. David Armstrong Mckay, the author of one of recent studies on the subject to Newscientist mag. here are explainers he's written before-
https://climatetippingpoints.info/2019/04/01/climate-tipping-points-fact-check-series-introduction/ (introduction is a bit outdated and there are some estimates that were ruled out in past year's ipcc report afaik but articles themselves are more up to date)
​
>www.climaterealitycheck.net/download
David Spratt and Ian Dunlop- authors of this "report" are same people who have written the report which was panned by scientists who fact-checked it- https://climatefeedback.org/evaluation/iflscience-story-on-speculative-report-provides-little-scientific-context-james-felton/
No-Effort-7730 t1_j8mptt2 wrote
Bumping for visibility because that's a dank ass based response.
Gemini884 t1_j8oka7k wrote
Except they're wrong.
​
>The IPCC infamously fails to account for carbon cycle feedbacks and their associated tipping points when setting their own emissions targets.
Then why are climate models used in previous IPCC reports so accurate and have predicted the pace of warming so well? Observed warming tends to track middle-of-the-range estimates from previous IPCC reports.
https://www.realclimate.org/index.php/archives/2022/02/another-dot-on-the-graphs-part-ii/
You probably should listen to what actual climate scientists say on the matter-
https://nitter.kavin.rocks/hausfath/status/1557421984484495362
https://nitter.kavin.rocks/hausfath/status/1491134605390352388
https://nitter.kavin.rocks/JoeriRogelj/status/1424743837277294603
https://nitter.kavin.rocks/PFriedling/status/1557705737446592512
https://nitter.kavin.rocks/ClimateAdam/status/1429730044776157185
https://nitter.kavin.rocks/Knutti\_ETH/status/1554473710404485120
https://nitter.kavin.rocks/ClimateOfGavin/status/1556735212083712002#m
There were some models for the recent ipcc report that overestimate future warming and they were included too
https://www.nature.com/articles/d41586-022-01192-2
There is no evidence for projected warming <3-4C of any tipping points that significantly change the warming trajectory. Read ipcc report and read what climate scientists say instead of speculating:
https://nitter.kavin.rocks/MichaelEMann/status/1495438146905026563
https://nitter.kavin.rocks/hausfath/status/1571146283582365697#m
"Some people will look at this and go, ‘well, if we’re going to hit tipping points at 1.5°C, then it’s game over’. But we’re saying they would lock in some really unpleasant impacts for a very long time, but they don’t cause runaway global warming."- Quote from Dr. David Armstrong Mckay, the author of one of recent studies on the subject to Newscientist mag. here are explainers he's written before-
https://climatetippingpoints.info/2019/04/01/climate-tipping-points-fact-check-series-introduction/ (introduction is a bit outdated and there are some estimates that were ruled out in past year's ipcc report afaik but articles themselves are more up to date)
>www.climaterealitycheck.net/download
David Spratt and Ian Dunlop- authors of this "report" are the same people who have written the report which was panned by scientists who fact-checked it- https://climatefeedback.org/evaluation/iflscience-story-on-speculative-report-provides-little-scientific-context-james-felton/
grundar t1_j8q46kv wrote
> There is no evidence for projected warming <3-4C of any tipping points that significantly change the warming trajectory.
Just to back up this point, r/science discussed a paper in Science which examined known tipping points 5 months ago. I extracted a list of those tipping points, their thresholds, their effects, and their timescales.
As you say, none of the near-warming (<4C) near-term (<200-year timescale) tipping points had significant global effects on warming or sea level rise.
[deleted] t1_j8oj3s9 wrote
[removed]
grundar t1_j8qdsbv wrote
> It's also no secret within academic climate science circles that the IPCC has long been politically motivated to underestimate the scale of the problem. Which is why very few climate scientists actually believe that the Paris Accord is realistic. We all know there is no chance the world can avoid 1.5 C mean global warming and that we will likely see a potentially disastrous 2 C increase by 2050. Many already assume that there will be no remaining carbon budget even for the 2 C target
That's an enormous number claims regarding what climate scientists believe, but the only source presented for any of it is a non-peer-reviewed report from an Australian think tank whose previous reports were criticized as alarmist, misleading, and lacking scientific credibility by scientist reviewers
And looking at the report itself, it's easy to see why. Their number 1 "critical understanding" cherry-picks only the IPCC scenarios which support their narrative:
> "Current (CMIP6) climate models project on average a warming of 0.3°C for the decade to 2030 (across the SSP2-4.5, SSP3-7.0 and SSP5-8.5 scenarios)."
By contrast, the IEA expects CO2 emissions to fall 15-20% by 2030, putting the world roughly in line with the IPCC's SSP1-2.6 pathway -- a pathway they totally ignore*.
It's reasonable that they would want to include higher-emission pathways as well to examine the danger of less likely scenarios, but to exclusively examine higher-emission scenarios and completely ignore lower-emission scenarios that are as or more plausible? It's clear cherry-picking of data to establish a chosen narrative.
On to their number 2 "critical understanding":
> "Due to model limitations, we will not know exactly how the climate crisis will unfold until it’s too late.6 One example is the failure to predict the intensity of extreme heat and flood events in Europe and North America in 2021."
i.e., they're conflating climate and weather.
One heat wave or one flood is weather; by contrast, climate is the broad long-term trend. Failing to predict a particular flood or heat wave no more "proves" the IPCC models wrong than a cold winter "proves" the climate is not warming. They're making an utterly unscientific argument here.
Not everything they say is wrong -- notably they're quite right that warming has already caused significant effects and even 1.5C (which is unlikely) will cause more -- but enough demonstrably biased and unscientific claims are thrown in that this report could never pass robust peer review and is not a scientific source.
[deleted] t1_j8n0575 wrote
[removed]
[deleted] t1_j8npo9i wrote
[removed]
[deleted] t1_j8ns2y2 wrote
[removed]
Hipoko t1_j8my2jo wrote
I dream to be as eloquent as you, SaxManSteve
Viewing a single comment thread. View all comments