Keeping global warming to within 1.5-2 degrees C may be more difficult than previously assessed, according to researchers. An international team of scientists has published a study in the Proceedings of the National Academy of Sciences (PNAS) showing that even if the carbon emission reductions called for in the Paris Agreement are met, there is a risk of Earth entering what the scientists call “Hothouse Earth” conditions.
“Human emissions of greenhouse gas are not the sole determinant of temperature on Earth. Our study suggests that human-induced global warming of 2 degrees C may trigger other Earth system processes, often called feedbacks, that can drive further warming—even if we stop emitting greenhouse gases,” says lead author Will Steffen from the Australian National University and Stockholm Resilience Centre. “Avoiding this scenario requires a redirection of human actions from exploitation to stewardship of the Earth system.”
Currently, global average temperatures are just over 1 degrees C above pre-industrial and rising at 0.17 degrees C per decade.
The authors of the study consider 10 natural feedback processes, some of which are “tipping elements” that lead to abrupt change if a critical threshold is crossed. These feedbacks could turn from being beneficial, by storing carbon, to a source of uncontrollable emission in a warmer world. These feedbacks are permafrost thaw, loss of methane hydrates from the ocean floor, weakening land and ocean carbon sinks, increasing bacterial respiration in the oceans, Amazon rainforest dieback, boreal forest dieback, reduction of northern hemisphere snow cover, loss of Arctic summer sea ice, and reduction of Antarctic sea ice and polar ice sheets.
“These tipping elements can potentially act like a row of dominoes. Once one is pushed over, it pushes Earth toward another. It may be very difficult or impossible to stop the whole row of dominoes from tumbling over. Places on Earth will become uninhabitable if ‘Hothouse Earth’ becomes the reality,” adds co-author Johan Rockström, executive director of the Stockholm Resilience Centre and incoming co-director of the Potsdam Institute for Climate Impact Research.
Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research, says, “We show how industrial-age greenhouse gas emissions force our climate, and ultimately the Earth system, out of balance. In particular, we address tipping elements in the planetary machinery that might, once a certain stress level has been passed, one by one change fundamentally, rapidly, and perhaps irreversibly. This cascade of events may tip the entire Earth system into a new mode of operation.”
“What we do not know yet is whether the climate system can be safely ‘parked’ near 2 degrees C above preindustrial levels, as the Paris Agreement envisages. Or if it will, once pushed so far, slip down the slope towards a hothouse planet. Research must assess this risk as soon as possible.”
Cutting greenhouse gases is not enough
Maximizing the chances of avoiding a “Hothouse Earth” requires not only reduction of carbon dioxide and other greenhouse gas emissions, but also enhancement and/or creation of new biological carbon stores, for example, through improved forest, agricultural and soil management; biodiversity conservation; and technologies that remove carbon dioxide from the atmosphere and store it underground, the paper says. Critically, the study emphasizes that these measures must be underpinned by fundamental societal changes that are required to maintain a “Stabilized Earth” where temperatures are ~2 degrees C warmer than the pre-industrial era.
“Climate and other global changes show us that we humans are impacting the Earth system at the global level. This means that we as a global community can also manage our relationship with the system to influence future planetary conditions. This study identifies some of the levers that can be used to do so,” concludes co-author, Katherine Richardson from the University of Copenhagen.
“… the climate system can be safely ‘parked’ near 2 degrees C above preindustrial levels”
What a load of BS, especially since we’ve been told all sorts of terrible consequences will occur at 2C and it is “officially unsafe“. Now apparently it’s “safe”. Got that folks? The climate pays attention to our history and the whims of the Schellnhuber pronouncements.
Note to my Internet stalker “Sou” aka Miriam O’Brien: I know you’ll want to jump all over this, please, be my guest. Make my day.
Of course they don’t bother to give a link to the paper in PNAS, and given the absurdity of the press release, I’m not going to bother looking for it. It’s not worth reading.
Here is the LINK to the PNAS paper.
Trajectories of the Earth System in the Anthropocene
http://www.pnas.org/content/early/2018/07/31/1810141115
The abstract is politically charged.
In case some user is interested in the full: https://workupload.com/file/rKyCzu9
The authors include Will Steffen, Johan Rockström, Katherine Richardson, Timothy M. Lenton, Diana Liverman and Hans Joachim Schellnhuber. They have published together variously on this theme for some time, common to all is Schellnhuber and his Potsdam Institute. The list is not exhaustive. Rockström is now taking over as Co-Director of Potsdam with Ottmar {Climate Change is now Wealth Distribution] Edenhofer.
February 2005
Breaking News – Only huge emissions cuts will curb climate change
https://www.newscientist.com/article/dn6964-only-huge-emissions-cuts-will-curb-climate-change/
“To have half a chance of curbing global warming to within safe levels, the world’s greenhouse gas emissions need to fall dramatically to between 30% and 50% of 1990 levels by 2050, a new study suggests.” This was actually Meinshausen, who then joined Potsdam in 2006. Formerly worked for Greenpeace and WWF as a “consultant”, has been the Director of the Australian-German College [Potsdam] at The University of Melbourne since 2012
February 2008
https://www.ncbi.nlm.nih.gov/pubmed/18258748
Lenton TM, Held H, Kriegler E, Hall JW, Lucht W, Rahmstorf S, Schellnhuber HJ.
“Here we introduce the term “tipping element” to describe large-scale components of the Earth system that may pass a tipping point. We critically evaluate potential policy-relevant tipping elements in the climate system under anthropogenic forcing, drawing on the pertinent literature and a recent international workshop to compile a short list, and we assess where their tipping points lie. An expert elicitation is used to help rank their sensitivity to global warming and the uncertainty about the underlying physical mechanisms”.
March 2009 Pre-Copenhagen
https://www.pik-potsdam.de/news/press-releases/files/synthesis-report-web.pdf
Rapid, sustained, and effective mitigation based on coordinated global and regional action is required to avoid “dangerous climate change” regardless of how it is defined.
Weaker targets for 2020 increase the risk of serious impacts, including the crossing of tipping points, and make the task of meeting 2050 targets more difficult and costly.
Authors include: Katherine Richardson, Will Steffen, Hans Joachim Schellnhuber, Diana Liverman
April 2009
Climate chaos predicted by CO2 study
“If we continue burning fossil fuels as we do, we will have exhausted the carbon budget in merely 20 years, and global warming will go well beyond 2C,” said Malte Meinshausen of the Potsdam Institute for Climate Impact Research in Germany, who led the study, published in Nature.
More pre-Copenhagen – September 2009
A safe operating space for humanity
https://www.nature.com/articles/461472a#author-information
Authors include:
Rockström, Johan
Steffen, Will
Lenton, Timothy M.
Schellnhuber, Hans Joachim
Hansen, James
Liverman, Diana
Richardson, Katherine
Anthropogenic climate change is now beyond dispute, and in the run-up to the climate negotiations in Copenhagen this December, the international discussions on targets for climate mitigation have intensified. There is a growing convergence towards a ‘2 °C guardrail’ approach, that is, containing the rise in global mean temperature to no more than 2 °C above the pre-industrial level.
Now Only Two Years Left
July 2017 – “Three years to safeguard our climate”
http://www.stockholmresilience.org/research/research-news/2017-07-02-three-years-to-safeguard-our-climate.html
Johan Rockström, Christiana Figueres, Hans Joachim Schellnhuber, Gail Whiteman, Anthony Hobley and Stefan Rahmstorf
They will never give up as long as the funding is there.
They are a dearh cukt like Pol Pot’s Khmer Rouge ir Jonestown’s Jim Jines.
Only much more dangerous since they are lustened to by Popes and Presidents.
Yet there is no such thing as the “Anthropocene”, according to geologists who are in charge of naming geological periods.
Oh dear……..well its being reported in countless reputable journals and publications…….maybe this crackpot one needs to wake up and smell the roses…..or is that wake up and smell the burning carbon?
I saw this on the BBC this morning where they included 60 metre sea level rises as part of this.
This crap made headlines in Sydney, Australia
https://www.smh.com.au/national/many-parts-of-earth-could-become-uninhabitable-study-s-grim-warning-20180807-p4zvwx.html
Is the author that disgraced alarmist who was run off for academic fraud?
Or is this author merely looking for new eays to beclown himself?
There will never be a runaway hothouse on Earth due to manmade CO2 and so-called feedbacks.
It is not physically possible.
It is not even good science fiction.
And the climate slimeballs want to censor us fir disagreeingvwith them.
How disgusting they are.
Every article by alarmists should include the definition of “alarmist”:
“someone who is considered to be exaggerating a danger and so causing needless worry or panic.”
The article is “alarmist”.
The authors are “alarmists.”
Thise who believe “alarmists” are “fools”.
Anthony.
The BBC covered this ‘story’ this morning – about which I’ve just complained!
Never complained before but their ongoing bias has finally pushed my over the edge….my complaint text follows:
BBC Radio 4, Today Programme. 7th Aug 18:
“In this morning’s interviews, 0639hrs Matt McGrath, and later interview – 0751hrs with Johan Rockström & Ovais Sarmad, the contributors gave a litany of catastrophic consequences resulting from Anthropogenic Global Warming, quoting the recent paper from the Stockholm Resilience Centre, “Trajectories of the Earth System in the Anthropocene” which starts: ‘We explore the risk that self-reinforcing feedbacks COULD push the Earth System toward a planetary threshold that, IF crossed, COULD prevent stabilization…’. [MY CAPITALS].
There were a number of problems with the radio piece which are concerning – all of which merit a response.
– There was no balance to the piece; it simply posited what now appears to be standard BBC ‘climate change propaganda’, without any apparent scepticism. A significant, and rising, majority of the UK population know that climate science questions remain unsettled, but by pushing the AGW agenda the BBC discredits its own value & this reinforces the rising perception by Mr Public Joe Soap that the BBC is biased. Either the hierarchy in the BBC is collectively biased & ignoring the impact that following this line is having on the public’s perception of them, or those in positions to effect a change are being badly advised by their resident scientists and environmentalists.
– No one provided a scientific basis for global warming resulting from increased CO2.
– No one offered a sceptical view that the report might be wrong – it was simply accepted as fact.
– There are many climate papers produced annually – why has the BBC publicise what appears to be the most dramatic yet?
– It cannot be a coincidence that a ‘hot weather oriented’ Thought for the Day piece proceeded it, followed swiftly by the ‘hot’ weather report. This smacks of tactics similar to James Hansen’s alarmism to Congress in 1988, where Hansen famously turned off the air conditioning and opened the window prior to his doom & gloom report which has now been widely discredited.”
I ran out of space for more. We’ll see where it goes.
Perhaps a complaint will also be forthcoming from Paul Homewood – whose posts I also follow.
Keep up the good work!
Dominic
It sounds like the BBC is the Brit’s version of CNN, only they have the misfortune of being forced to pay for it.
NCEP global temperature is 0.145 c above the 1981-2010 average.This is a cold hothouse!
We are in an Ice Age. The likelihood of veering madly off into Hothouse conditions is slightly above zero %. These idiots are just creating a new set of talking/study points out of thin air and gullibiity. They should be put to work picking up trash in ditches.
Someone should break it to them that it stopped warming 18 years ago and is actually cooling now.
““… the climate system can be safely ‘parked’ near 2 degrees C above preindustrial levels”
What a load of BS, especially since we’ve been told all sorts of terrible consequences will occur at 2C and it is “officially unsafe“. Now apparently it’s “safe”. Got that folks?”
Misreading
Safely parked at 2C, means only that there is no additional warming, not that 2C is safe
Safely modifies parked.
jeez
The study is silly but the criticism is sillier.
“Safely parked” = “terrible consequences” ??
You make no sense..your comment is the silliest !!
Will that horrific 2c rise in 250 years get us out this dang tiresome ice age we are still in…..
Will it make us inter-glacially endowed Mosher ?.
Inter-glacial-ist deniers.
Ice age? Lol, dude that is so last century.
Loss of arctic sea ice is a net negative feedback. It allows the relatively warm ocean to emit a huge amount of energy to space, and to lose it by latent evaporation.
The reduction in albedo isnt great, old sea ice is not shiny white, and at the low levels of incidence in the arctic water is quite reflective. The region also has a lot of cloud cover in summer, so there isnt much solar energy at the surface anyway.
Schellnhuber ? No, really, that has to be a #fakename
Oh to be benevolently guided by well meaning Marxist scientists in a future of enforced poverty, 3rd world conditions, and early deaths of privation in the re-education camps.
What’s not to like?
“Keeping global warming to within 1.5-2 degrees C may be more difficult than previously assessed, according to researchers.” I don’t think so.
The following graph is an estimate of the global temperature trend over the near term. The rate of change (first derivative) of the global mean temperature trend-line (6th degree polynomial fitted to HadCRUT4 monthly database) has been constant or steadily decreasing since October 2000. The HadCRUT4 temperature anomaly has decreased by nearly 40 percent from March 2016, the El Nino peak, to July 2017. The rate of change of the trend-line will likely become negative within the next 20 years, reaching the lowest global mean trend-line temperature in almost 40 years. Lower temperatures could persist for decades.
Since October 2000, global mean temperature trend-line has decreased from 0.20 degrees C per decade to 0.12 degrees C per decade. Based on near-term estimates, global warming over the next 100 years could very likely be much lower than 2.0 degrees C.
Will Steffen says, “Avoiding this scenario (“Hothouse Earth”) requires a redirection of human actions from exploitation to stewardship of the Earth system.” Really? Who on Earth has the qualifications and a large enough ego to be steward of earth? I would argue she has yet to identified. And as far as I know, there has been no Second Coming.
draft ref: An-Analysis-of-the-Mean-Global-Temperature-in-2031 at http://www.uh.edu/nsm/earth-atmospheric/people/faculty/tom-bjorklund/