Via press release from the Max Planck Society for the Advancement of Science
New carbon dioxide emissions model
Meteorologists have determined exactly how much carbon dioxide humans can emit into the atmosphere while ensuring that the earth does not heat up by more than two degrees
The Intergovernmental Panel on Climate Change (IPCC) calculated projected temperature changes for various scenarios in 2007 and researchers at the Max Planck Institute for Meteorology in Hamburg have now gone one step further: they have developed a new model that specifies the maximum volumes of carbon dioxide that humans may emit to remain below the critical threshold for climate warming of two degrees Celsius. To do this, the scientists incorporated into their calculations data relating to the carbon cycle, namely the volume of carbon dioxide absorbed and released by the oceans and forests. The aim of the international ENSEMBLES project is to simulate future changes in the global climate and carbon dioxide emissions and thereby to obtain more reliable threshold values on this basis. (Climatic Change, July 21, 2010)
Fig.: Evolution of the carbon dioxide emissions calculated by the model (left) and the temporal development of the global mean annual temperature (right). In order to achieve the long-term stabilisation of the atmospheric carbon dioxide concentration, fossil carbon dioxide emissions must be reduced to around zero by the end of the century. The black lines represent the observed values. (GtC/year = gigatons carbon/year)
Image: Max Planck Institute for Meteorology
The concentration of carbon dioxide in the atmosphere caused by the combustion of fossil fuels (gas, oil) has increased by around 35 percent since the beginning of the Industrial Revolution. If carbon dioxide emissions and, as a result, atmospheric carbon dioxide concentrations continue to increase unchecked, a drastic increase in the global temperature can be expected before the end of this century. With the help of new models for a prescribed atmospheric carbon dioxide concentration, scientists from all over Europe have now calculated for the first time the extent to which the global carbon dioxide emissions must be reduced to halt global warming.
“What’s new about this research is that we have integrated the carbon cycle into our model to obtain the emissions data,” says Erich Roeckner. According to the model, admissible carbon dioxide emissions will increase from approximately seven billion tonnes of carbon in the year 2000 to a maximum value of around ten billion tonnes in 2015. In order to achieve the long-term stabilisation of the atmospheric carbon dioxide concentration, the emissions will then have to be reduced by 56 percent by the year 2050 and approach zero towards the end of this century. Although, based on these calculations, global warming would remain under the two-degree threshold until 2100, further warming may be expected in the long term: “It will take centuries for the global climate system to stabilise,” says Erich Roeckner.
The scientists used a new method with which they reconstructed historical emission pathways on the basis of already-calculated carbon dioxide concentrations. To do this, Erich Roeckner and his team adopted the methodology proposed by the International Panel on Climate Change (IPCC) for simulations being carried out for the future Fifth IPCC Assessment Report: earth system models that incorporate the carbon cycle were used to estimate the anthropogenic carbon dioxide emissions that are compatible with a prescribed concentration pathway. In this case, the emissions depend solely on the proportion of the anthropogenic carbon in the model that is absorbed by the land surface and the oceans. Repetition of the experiments using different pre-industrial starting dates enabled the scientists to distinguish between anthropogenic climate change and internal climate variability.
The model used for this study is based on a low-resolution spatial grid with a grid spacing of around 400 kilometres, which takes the atmosphere, plus the land surface, the ocean, including sea ice, and the marine and terrestrial carbon cycle into account.
The overall aim of the study is to simulate future changes in the climate and carbon dioxide emissions in a single scenario in which the carbon dioxide equivalent concentrations in the atmosphere are stabilised in the long term at 450 parts per million (ppm), so that global warming increases to a maximum of two degrees above the pre-industrial level. The data are currently being evaluated by other European climate centres. “As soon as all of the results are available, we can evaluate the spread between the models,” says Erich Roeckner. “The more significant the data we have, the more accurate our forecast will be.”
Related links:
[1] Website of the ENSEMBLES project
Original work:
Erich Roeckner, Marco A. Giorgetta, Traute Crueger, Monika Esch, Julia Pongratz
Historical and future anthropogenic emission pathways
“It will take centuries for the global climate system to stabilise,” says Erich Roeckner.
Ya think? When was the last time the ‘global climate system’ was stable?
Perhaps the Institute could lead by example?
So they invent the scariest scenario possible; no energy usage from burning anything and they can only be bothered to model down to a 400 km grid spacing.
That’s about as good as holding your finger up to find out which is the sunny side.
These people ought to be tarred and feathered and put out in the town square in the stocks for people to throw rotten tomatoes at.
Did you notice how careful they were to mention that they took clouds into consideration; oh maybe I read that in somebody else’s paper talking about the source of tornadoes.
What a misleading headline, Anthony! The article says that if a 2 deg C goal is to be met, then CO2 emissions must be dramatically reduced. The headline would have us forget about the first half of that conditional. They are not saying emissions must drop; they are saying that IF we want to meet the 2 deg C GHG goal, THEN emissions must drop. That is an extremely important difference.
Yeah, that’s doable.
I promise to stop all use of fossil fuels 90 years from now.
Hell, I’ll make that promise for 50 years from now. I might regret it on my 103’rd birthday but what the heck, I’m as enviromentally conscious as the next guy.
“the emissions will then have to be reduced by 56 percent by the year 2050 and approach zero towards the end of this century. Although, based on these calculations, global warming would remain under the two-degree threshold until 2100, further warming may be expected in the long term: “It will take centuries for the global climate system to stabilise,” says Erich Roeckner.”
Sigh, the last quote first, “It will take centuries for the global climate system to stabilise,” says Erich Roeckner.”———Will someone send this pinhead a note telling him the climate system has never been stable?
CO2 emissions to zero?? So, are they planning the mass suicide by kool-aid? Or do they think we’ll have developed a different manner of breathing by then? I’ll gladly stand in line for the kool-aid, but every enviro whack-job has to stand in front of me. When the last one drinks the kool-aid, well, we might not have to drink anymore. We’ll measure the CO2 emissions then and see if zero is really necessary.
From the ENSEMBLES home page: “an objective probabilistic estimate of uncertainty in future climate at the seasonal to decadal and longer timescales” . This is an oxymoron at best. No such thing as “objective probability”. All probabilities are subjective. And when combined with the rest of the phrase is total [snip]!
GIGO
“It will take centuries for the global climate system to stabilise,” says Erich Roeckner.
Has the Earth’s climate ever been stable?
New carbon dioxide emissions model: “carbon dioxide emissions must be reduced to around zero by the end of the century”
====================
I’ve run my own CO2 emmision model, and it says:
“Number of CAGW believers must be reduced to around zero by Friday”
I’ve spent half day trying to find out why my model f****d up day of the week.
“[…] Meteorologists have determined exactly how much carbon dioxide humans can emit into the atmosphere while ensuring that the earth does not heat up by more than two degrees. […]”
Exactly? Oh, suuuuure….. Lord willin’ and the creek don’t rise.
Color me skeptical. That’s an awful lot of certainty there.
What better way to build a graph to show a rise in temperature over time then pick the starting point in the middle of a cool period. Presto castastrophic warming…
I think that Max and his buddies need to spend more time studying CO2 rather than models.
” namely the volume of carbon dioxide absorbed and released by the oceans and forests.”
No one knows this.
They didn’t even adjust for plankton levels going down.
Plankton goes down, oceans take up less CO2.
Won’t happen, too many main CO2 emitters have given them the finger.
They are just buying into the long term, and trying to make themselves a player for more government/grant money.
Zero. That sounds good. Hey wait, *I* emit carbon dioxide!
They really “believe” this stuff, don’t they!
looks like more play station tom foolery.
Oh, and it’s based upon a model, based upon IPCC methodology, which is based upon what? WUWT?
Here is the key: ““What’s new about this research is that we have integrated the carbon cycle into our model to obtain the emissions data,” says Erich Roeckner. According to the model, admissible carbon dioxide emissions will increase…”
alGore wanted to be carbon free by 2015.
He did pay 540 dollars so that means he doesn’t expect everything to be free
We will have a lot more rubber car tires to burn by the end of the century.
India and China have 75% of their people burn coal, charcoal, trash, wood to heat and cook. I suspect most humans will ignore this Eutopian ideology. There may be a few people that shut down their CO2 ouput. I can’t begin to explain how the claimant is really kidding themselves if they think they know what all produces CO2 and how it can be stopped. It takes 1,350 tons of coal to make steel for a 850 ton wind turbine tower. Let them find a carbon free Bessimer steel process.
How many ways can this be wrong?
1. The current temp rise is wrong. See Ross McKitrick’s paper.
2. The projected temperature rise is wrong. It might go 1 degree. It might go down 1 degree. It may do nothing. Only the sun will tell.
3. The projected carbon use is wrong. The Asian countries will take up any fossil fuel use that the West gives up. But that won’t make any differene to the temperature.
4. “It will take centuries for the global climate system to stabilise,” says Erich Roeckner. Wrong. It’s stable now.
“Meteorologists have determined exactly how much carbon dioxide humans can emit into the atmosphere while ensuring that the earth does not heat up by more than two degrees”
In other news, demographers have also determined exactly what the US population will be in 2052, what every person in the US will have for breakfast on April 15, 2052, and who will be elected Principal of the Semi-United States in Gorevember (hint: she will belong to the Kool-Aid Party and hasn’t been born yet). Democrats are already demanding a recount.
Oops, “US” should be “SUS”. Dang models!
Sorry mods. I skipped a bit and went went right for the jugular. Feel free to delete all comments (not post as some say, but I’m a stickler for the proper use of terms ans spelling/grammar (it really aids the discussion when no one is questioning your use of the language (and we are using English, right?))). Nice parentheticals.
[REPLY – I gave up on grammar/usage fascism decades ago. In the end, it’s the thought that counts, not the form. ~ Evan]
“The concentration of carbon dioxide in the atmosphere caused by the combustion of fossil fuels (gas, oil) has increased by around 35 percent since the beginning of the Industrial Revolution.”
I’m not a scientist, merely a casual reader. Question: What is the percentage of CO2 from fossil fuels compared to other sources? The above statement rings of someone spinning data. Human related CO2 emissions could be a very small part of the overall picture, yet the 35% makes it sound very scary. Could someone please enlighten me?
Thanks.
[REPLY – It accumulates little by little over time. We add c. 8 Bil. Metric Tons Carbon to the atmosphere. Half accumulates, the other half is absorbed by other sinks. There’s c. 760 BMTC in the atmosphere already. So it accumulates at c. half a % per year. My opinion, though, is that this has little effect. ~ Evan]