From EGU
1.5 C vs 2 C global warming: New study shows why half a degree matters
European researchers have found substantially different climate change impacts for a global warming of 1.5°C and 2°C by 2100, the two temperature limits included in the Paris climate agreement. The additional 0.5°C would mean a 10-cm-higher global sea-level rise by 2100, longer heat waves, and would result in virtually all tropical coral reefs being at risk. The research is published today (21 April) inEarth System Dynamics, an open access journal of the European Geosciences Union, and is presented at the EGU General Assembly.
“We found significant differences for all the impacts we considered,” says the study’s lead author Carl Schleussner, a scientific advisor at Climate Analytics in Germany. “We analysed the climate models used in the [Intergovernmental Panel on Climate Change (IPCC)] Fifth Assessment Report, focusing on the projected impacts at 1.5°C and 2°C warming at the regional level. We considered 11 different indicators including extreme weather events, water availability, crop yields, coral reef degradation and sea-level rise.”
The team, with researchers from Germany, Switzerland, Austria and the Netherlands, identified a number of hotspots around the globe where projected climate impacts at 2°C are significantly more severe than at 1.5°C. One of these is the Mediterranean region, which is already suffering from climate change-induced drying. With a global temperature increase of 1.5°C, the availability of fresh water in the region would be about 10% lower than in the late 20th century. In a 2°C world, the researchers project this reduction to double to about 20%.
In tropical regions, the half-a-degree difference in global temperature could have detrimental consequences for crop yields, particularly in Central America and West Africa. On average, local tropical maize and wheat yields would reduce twice as much at 2°C compared to a 1.5°C temperature increase.
Tropical regions would bear the brunt of the impacts of an additional 0.5°C of global warming by the end of the century, with warm spells lasting up to 50% longer in a 2°C world than at 1.5°C. “For heat-related extremes, the additional 0.5°C increase marks the difference between events at the upper limit of present-day natural variability and a new climate regime, particularly in tropical regions,” explains Schleussner.
The additional warming would also affect tropical coral reefs. Limiting warming to 1.5°C would provide a window of opportunity for some tropical coral reefs to adapt to climate change. In contrast, a 2°C temperature increase by 2100 would put virtually all of these ecosystems at risk of severe degradation due to coral bleaching.
On a global scale, the researchers anticipate sea level to rise about 50 cm by 2100 in a 2°C warmer world, 10 cm more than for 1.5°C warming. “Sea level rise will slow down during the 21st century only under a 1.5°C scenario,” explains Schleussner.
Co-author Jacob Schewe, of the Potsdam Institute for Climate Impact Research in Germany, says: “Some researchers have argued that there is little difference in climate change impacts between 1.5°C and 2°C. Indeed, it is necessary to account for natural variability, model uncertainties, and other factors that can obscure the picture. We did that in our study, and by focusing on key indicators at the regional level, we clearly show that there are significant differences in impacts between 1.5°C and 2°C.”
William Hare, a senior scientist and CEO at Climate Analytics who also took part in the Earth System Dynamics research, adds: “Our study shows that tropical regions – mostly developing countries that are already highly vulnerable to climate change – face the biggest rise in impacts between 1.5°C and 2°C.”
“Our results add to a growing body of evidence showing that climate risks occur at lower levels than previously thought. It provides scientific evidence to support the call by vulnerable countries, such as the Least Developed Countries and Small Island Developing States, that a 1.5°C warming limit would substantially reduce the impacts of climate change,” says Hare.
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As climate models fail to produce any meaningful result, we are talking individual opinions.
So far the global warming component is 0.1 degree Celsius. How many centuries it is going to take to reach 1.5 degrees Celsius. Such trash articles has any significance?.
Dr. S. Jeevananda Reddy
Considering the near logarithmic impact of additional CO2 and the fact that the bandwidths absorbed by CO2 are either fully or almost fully saturated already, I would say it would take an infinite number of centuries to reach 1.5C.
It is meaningless drivel.Really this is post-modernist guff in full .Embarressing.Zu befehl!
Climate models certainly fail to predict the impact of doubling CO2 but the immutable physics is pretty clear that the most warming it can cause is under 1C, so doing nothing would be the best course. Unfortunately, the physics contradicts the narrative, so the IPCC’s self serving ‘consensus’ suppresses the constraints imposed by physical laws so that it can justify its regressive agenda of redistributive economics under the guise of climate reparations. It’s unbelievable to many that politics, especially the politics they agree with. can turn ostensibly intelligent scientists into idiots and this is what makes overturning the narrative so difficult.
..Notice they don’t mention the BENEFITS that all Northern regions would experience with a few degrees of warmth, especially Canada ..I wonder how many people realize that 90% of the population,of the world’s second largest country, live within 200 miles of the U.S. border ?? Why ?? Because it’s $#%^ing COLD !!
I thought that global warming was supposed to heat the poles more than the tropics. This sounds as though they are saying the opposite. Which is the case? It also sounds as though the models they are analysing ( not something boring like measurements of the real world) are the same models we already know don’t work. I am getting so tired of this madness. Where is the healthy doubt?
Exactly.
Global warming is anything but global in nature; according to satellite data, the tropics have seen very little warming for the past 37 years, so why should they certainly experience significant warming during the next 80 or so years;
See:
http://www.climate4you.com/images/MSU%20RSS%20TropicsAndExtratropicsMonthlyTempSince1979%20With37monthRunningAverage.gif
Correct, Richard.
During all Ice Ages, the tropics remained firmly tropical. No glaciers in Brazil.
Aren’t the western half of the Andes on the Brazilian border?
Where is the health doubt?
How can one have doubt when the story is a big lie and they know it, but it pays well.
Yes, warms more where it is colder and drier…but those areas benefit from it. Shhhhhh 😉
The tropics must heat up in order to create the greater potential for transport of heat, the heat needs to be there in the first place so if the tropics are not heating up then they are not overly warming the poles than at any other time in history.
It’s a bit like the Troposphere warming, the oceans ate it maybe? 😀
They say the Poles are most affected by global warming when it suits them, and then they switch to the Tropics when that suits them. Doublespeak!
I wish this would come out in the articles as well. Every study has shown that overall mortality would decrease by millions of people if temperatures were to rise that extra 0.5C. They talk about a few cm rise in water amounting to a couple inches and then forget to mention a million lives saved from reduced deaths from cardiac, pneumonia and numerous other conditions as proven by Lancet and other studies. Unfortunately there is no way even if we continued pumping exponentially greater co2 into the atmosphere we’d ever get that rise from co2 alone. So, the whole discussion is pointless.
Since 1650 to 1880 : +0.5C with 0ppm change in CO2
Since 1880 ro 1945: +0.4C with 30ppm change in CO2
Since 1945 to 2015: +0.3C with 100ppm change in CO2
TO 2100: +0.3C with 200ppm change in CO2
Total change = 1.5C. Of course less than half this can possibly be ascribed to CO2
Chances of getting to 2C unknown but from CO2 (0% we’d need to pump 1000ppm above predicted levels to get anywhere near another 0.5C)
The ice ages see a change in CO2 of roughly 100ppm from changing solubility of CO2 in the ocean. Temperatures go up 8C during the ice ages but have risen maybe 0.7C or 1/10th the ice ages for pumping 50% MORE THAN an ice age variation of CO2 into the atmosphere. Conclusion: CO2 doesn’t cause the change they predicted it would. Not even close. My blog http://logiclogiclogic.wordpress.com has several articles that explain how they went wrong.
Of course this is not about science anymore. They just say whatever they want and the press reports it as fact never fact checking any previous predictions they’ve made. I have a blog at the above address on the 50+ prediction failures.
It would be ‘useful’ if links to relevant documents were included in reports, where available
Full article free – 25 page PDF
Differential climate impacts for policy-relevant limits to global warming: the case of 1.5 ◦C and 2 ◦C
http://www.earth-syst-dynam.net/7/327/2016/esd-7-327-2016.pdf
Earth Syst. Dynam., 7, 327–351, 2016
http://www.earth-syst-dynam.net/7/327/2016/
doi:10.5194/esd-7-327-2016
© Author(s) 2016. CC Attribution 3.0 License.
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EGU website
http://www.egu.eu/news/230/15c-vs-2c-global-warming-new-study-shows-why-half-a-degree-matters/
So how, exactly, do a bunch of computer model runs constitute “evidence”? And how does this “growing body of evidence” look without them?
Pure fantasy.
Exactly. They didn’t “find” anything. They are predicting.
They don’t. Computer models are literally the researchers’ hypothesis…in computer form. Computer modeling of uncertain systems has a very high probability of doing nothing more than confirming your own existing bias.
That got me too. All of their “evidence” comes from computer models. They don’t have a clue what evidence really is, for them it’s all opinion and programming. And then they think that’s robust!
“Climate Scientists” have been belaboring for years under the delusion that a computer model is an experiment.
If you know nothing else about them, this one tidbit of information tells a person about all one needs to know in order to assess their credibility.
In Mediterranean Italy (from Tuscany to Sicily) there was no drought whatsoever during last decade or even more. Actually Italians often mock old alarms/reports from the ’90ies, stating that “Southern Italy and Sicily are going to be a desert”, because last years problems were all due to floodings, so the excess of water, rather than its lack. It would be anyway likely that some part of Sicily could become a desert: but that is due to bad soil management, not to (still-to-be-seen) climate change. I think that they misunderstand the recent drought in the Near East: first of all, they misunderstand Syria for all Mediterranean region; and second, they misunderstand a single event (until now, we really cannot say anything more) for a long-term trend.
Filippo, Bold Letters –
Actually Italians often mock old alarms/reports from the ’90ies, stating that “Southern Italy and Sicily are going to be a desert”, because last years problems were all due to floodings, so the excess of water, rather than its lack.
Thanks -Hans
(This is a clearly a strange new use of the word “evidence” I wasn’t previously aware of – h/t the great Douglas Adams)
And the old coral reef destruction bullshit is repeated
Yep, the 15 or so natural causes of bleaching ignored. All of it blamed on CAGW.
Now we have every possible negative climatic impact blame directly on a poorly understood global average temperature, which is a fictitious entity that means nothing to the climatic systems that created the residue.
The individual temps matter not the average, the earth’s weather system doesn’t care about global average temperature, especially one that is more fiction than fact.
It’s modeled, therefore it is…
I model, therefore I earn (an income)
Even the artificial causes are almost always due to effluent and toxins. You know, what environmentalists used to blame it on back before CO2 became responsible for everything.
And the old coral reef destruction bullshit is repeated
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coral reefs are found almost exclusively in the hottest waters on earth. here is my challenge to the climate science community. tell us specifically where the ocean waters are too hot for coral to grow? Outside of volcanic vents, no such place exists.
notice when they talk about coral bleaching, they don’t say coral death. because bleaching doesn’t kill the coral polyp. what happens is that the polyp kicks the “cold” algae out of the house, because the algae isn’t paying its rent, and it is the algae that gives coral its color.
and then the polyp puts up a room for rent sign, and waits for algae better able to pay the rent. and when a new “hot” algae moves in, the coral bleaching is over. sort of like divorce, you move out the cold partner and bring in a hot one. well that is the plan anyways, doesn’t always work out that way.
“… sort of like divorce, you move out the cold partner and bring in a hot one. well that is the plan anyways, doesn’t always work out that way.”
Great analogy! I love that 🙂
But…but…but
Aren’t the greatest coral reefs in the Artic and Antarctic Oceans?
No sarc here! (nudge nudge wink)
“The growing body of speculation.”
Is this the new dogma, forget the actual physics of atmosphere and ocean and blame temperature.
So all of these things are derived from an estimated residue of climatic changes?
it seems like it is straight out of the Trenberth school of climate science.
My faith in science has been smashed this past decade
‘With a global temperature increase of 1.5°C, the availability of fresh water in the region would be about 10% lower than in the late 20th century. In a 2°C world, the researchers project this reduction to double to about 20%.’
: rising temperature – less precipitation : sure?
It is amazing they are actually attempting to reduce the earth’s not well understood system to temperature. A temperature we can’t actually currently accurately measure.
It is insanity!
Only a study on the regions of earth and how climates and events will interact, and in fact high resolution of those events would help. They are bypassing essentially all the science we do understand on atmosphere and ocean and going with purely a guessed temeprature residue and claiming it is a driver.
Global average temperature is useless as a driver of future changes as past changes created the average temp residue and those past changes lead into the short term changes in the future, nothing happening with global average temp now will have any bearing on what the world will be like in 2100, someone should tell these idiots called “scientists” that..
not sure why they are worried, Australia is off the richter scale scale of hotter than the UK and yet-
“The primary reason Australian wheat yields are relatively low by international standards is the fact that Australian farmers have become highly specialised in low rainfall farming techniques. As a result, the Australian Wheatbelt has extended inland over time to areas where rainfall is lower. Indeed, the majority of the Wheatbelt receives low to medium rainfall, with the largest single category of farms by land area being in the low rainfall areas”
And of course part of their success in low rainfall farming is the extra CO2.
And of course there are our successes in a wide variety of sports, especially on a per capita basis!
In fact global average temperature is a fiction that does not play a part in anything that happens with weather or climate, it is a useless residue, erm… metric.. no wait residue! 😀
it is pseudo science and pure delusion to predict the future based on global average temperature
We considered 11 different indicators including extreme weather events, water availability, crop yields, coral reef degradation and sea-level rise.”
The team, with researchers from Germany, Switzerland, Austria and the Netherlands, identified a number of hotspots around the globe where projected climate impacts at 2°C are significantly more severe than at 1.5°C. One of these is the Mediterranean region, which is already suffering from climate change-induced drying. With a global temperature increase of 1.5°C, the availability of fresh water in the region would be about 10% lower than in the late 20th century. In a 2°C world, the researchers project this reduction to double to about 20%.
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Armageddonism, alarmism, catastrophism, exaggerationism, nonsesimism – the MSM seeks for; but I wonder how interested the average reader still trusts on that.
I stopped reading when they said “we analysed climate models…”
I guess that constitutes scientific research these days.
what about randomness and uncertainty?
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2763358
This obsession with global average temperature is ridiculous and I can only imagine it is to serve as a false point of debate, as in no one really believes it matters and it is designed to draw attention, it really is not worth discussing.
” … we analysed climate models … ”
When will they look out of the window, or even go for a walk in the countryside and talk to an old farmer?
Of course, I forgot, silly me, talking to old farmers is heresay, not data.
As I have to remind the environmentalists
The plural of anecdote, is not data.
The reality is not the model result. Surely you can understand that? Computers rule!
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no news in the media until now.
So they’re producing their Sensationalisms in the save space.
Spreading afterwards.
Too bad they didn’t use the Lewis, Curry model. The world would have been saved.
Ooh apparently the Mediterranean is drying out! lol
Those dry periods during the Roman empire, the med droughts, must have been caused by CO2’s temporal influence baaahahaha.
The med has been far dryer in the past.
Drought and the fall of Rome from cold induced droughts.
http://www.ancientworldreview.com/2008/12/drought-and-the-fall-of-rome.html
It sounds like a precursor to some parametric tweaking to bring modelled CO2 sensitivity more into line with observations, whilst ensuring the gravy train stays on the rails. The climate ponzi is far too big to be allowed to fail.
I wonder how long until we see studies claiming the climate of the Little Ice Age was actually benevolent, and that crop failure and famine in this period were merely due to political unrest? It would follow that only a return to this state could save the planet (money on the plate please)..
If you look at the history of NOAA adjustments it is clear they are trying to bring the temp record in line with the CO2 growth curve.
Thrown in Mann’s hockeyschtick and that takes the revisionism back 1000 years in order to match what CO2 driven models produce.
And it also allowed the planet to rejuvenate, otherwise the soil would have been worn out! Always think of the planet, and the children (and the grants)!
Thou shallst believe!
1. CO2 drives temperature / cooling, warming ad lib.
2. Temperature drives weather / draining, drowning ad lib.
3. Live on earth drives impact to extremes. Until now we’re up to 11 counts of evidence.
No proofs to date, but ever confident.
The geopalaeloclimate experts hold records of the planet feedback accelerated unstoppable going into death spirals forced by GHGs. – wait – not yet, but we’ll find.
Wait and see!
I thought I recognised ‘Climate Analytics’.
See the projections for 2100 about half way down this piece from the ever willing to repeat the press release rather than read the study BBC:
http://www.bbc.co.uk/news/science-environment-36098310
This nut of the BBC I am aware of, I had it out with this guy over his claims of glacier retreat, when I pointed out his two posterboy glaciers were retreating since 1800s, he went dark and my posts disappeared.
Typical
Why don’t they bring solid, basic, usefull new findings in the real world – does’nt pay?
Science the institution stopped being experimental a century ago and instead retreated to the cosy concept building world of mathematics, that place where reality is not on the “list” the doorman has
I know, you take a complicated pde with defined boundary conditions to a mathematician and you may get an answer like “the problem is irreducible in the general case.” When you go over it with them you realize that to them the general case involves number realms for beyond the reals. When you mention that it needs to be reduced to the real observable world you get an answer like “oh I didn’t know you wanted the trivial case” and gives you a very acceptable answer. Some mathematicians live in a strange mental world.
For decades, 2°C has been promoted as the limit we need to hold warming to, on the grounds that that’s the point at which the harmful effects start to outweigh the benefits. In other words, any warming up to and including 2° actually leaves us better off.
Why then, at the recent Paris conference was it decided to lower the target to 1.5° ? By all the arguments put forward by the alarmists, we’re supposed to be better off with 2° of warming than 1.5°.
To my eyes, it’s really simple. With one sixth of the century gone already, and no warming at all so far, it becomes increasingly obvious that there’s little or no prospect of so much as 2° of warming by 2100. That leaves policy makers with two options – abandon the anti-carbon crusade, or set a new, lower, target.
They took the obvious decision. Now they need evidence to support. Expect more where this came from.
Yours is the correct analysis of what is (regrettably) happening here. “Business as usual” looks like it will result in under a 2C increase which is benign. This gives the control freaks no leverage and so they must move the goal posts.
I asked right after Paris what difference half a degree would make and here is their response; but it is important to remember that this “growing body of evidence” comes months after they had made their minds up that 1.5C was the new “tipping point”.
Cause = Need to control
Effect = “New evidence suggests…”