For the “business-as-usual” scenario RCP8.5, the model-mean changes in 2090s (compared to 1990s) for sea surface temperature, sea surface pH, global O2 content and integrated primary productivity amount to +2.73 °C, −0.33 pH unit, −3.45% and −8.6%, respectively.Ok, tell me I'm not the only one for whom those numbers are a "Holy ---k" moment. Not the first one - actually it's less alarming than many projections. But the others ... kiss seafood goodbye, prepare for war over food produced on land, and wheeze like an asthmatic while fighting for that food.
QuoteFor the “business-as-usual” scenario RCP8.5, the model-mean changes in 2090s (compared to 1990s) for sea surface temperature, sea surface pH, global O2 content and integrated primary productivity amount to +2.73 °C, −0.33 pH unit, −3.45% and −8.6%, respectively.Ok, tell me I'm not the only one for whom those numbers are a "Holy ---k" moment. Not the first one - actually it's less alarming than many projections. But the others ... kiss seafood goodbye, prepare for war over food produced on land, and wheeze like an asthmatic while fighting for that food.
Major reductions in the fatty acid ( FA ) content of diatoms in response to climate change may seriously impact food webs. " Algae inhibiting brine channels of the ice ,in particular diatoms, contribute significantly to primary production in ice covered polar areas, providing a substantial carbon source to higher levels." Discussion paper at link below. http://www.biogeosciences-discuss.net/10/6637/2013/bgd-10-6637-2013.html (http://www.biogeosciences-discuss.net/10/6637/2013/bgd-10-6637-2013.html)
ggelsrinc, I thought you said you were a chemist by training so maybe you can answer this better than I can. Here is emissions of chemicals that cause acid rain. When coal is burned, carbon dioxide, sulfur dioxide, nitrogen oxides, and mercury compounds are released. For that reason, coal-fired boilers are required to have control devices to reduce the amount of emissions that are released.
The average emission rates in the United States from coal-fired generation are: 2,249 lbs/MWh of carbon dioxide, 13 lbs/MWh of sulfur dioxide, and 6 lbs/MWh of nitrogen oxides.3
Mining, cleaning, and transporting coal to the power plant generate additional emissions. For example, methane, a potent greenhouse gas that is trapped in the coal, is often vented during these processes to increase safety.
Oil
Burning oil at power plants produces nitrogen oxides, sulfur dioxide, carbon dioxide, methane, and mercury compounds. The amount of sulfur dioxide and mercury compounds can vary greatly depending on the sulfur and mercury content of the oil that is burned.
The average emissions rates in the United States from oil-fired generation are: 1672 lbs/MWh of carbon dioxide, 12 lbs/MWh of sulfur dioxide, and 4 lbs/MWh of nitrogen oxides.4
In addition, oil wells and oil collection equipment are a source of emissions of methane, a potent greenhouse gas. The large engines that are used in the oil drilling, production, and transportation processes burn natural gas or diesel that also produce emissions.
Add up sulfur dioxide and nitrogen oxides produced and compare them to the 30+ giggatonnes of Co2 emitted annually. The oceans are absorbing 10+ giggatonnes of Co2 emissions annually so my question to you is how many tons of sulfur dioxide and nitrogen oxides are the oceans absorbing?
There is a little more to it than that to calculate all those emissions from the industrial age that would acidify an ocean. We get a lot of CO2 from making cement and many ores are sulfides, like nickel, zinc, lead, mercury, silver and copper. We also have the sulfur emissions to make coke for the steel industry. We make a lot of hydrogen sulfide making paper. There's a lot of hydrogen sulfide in natural gas, sometimes 90%. If it's taken out of the ground, it has to be somewhere and the Earth has plenty of sulfur, it's a cheap nasty fuel. Sewage is another source for H2S and rice production for methane and it's all going to acidify.
We can remove some of the metal pollutants and mercury tends to get the most press, but those scrubbers aren't very efficient. If there are other metals around, like cadmium, vanadium and arsenic, it will find it's way into that coal and other fuels. Sometimes coal deposits have a sulfur layer that will spontaneously ignite in areas where it's been piled up from a coal mine.
ggelsrinc, Of course there are natural cycles for nitrogen, sulfur, and Co2. You were talking about acid rain. So2 and nitrogen oxides are the primary cause. U.S. Emissions of So2 reduced 83% in last few
decades.
NOx emission by U.S. not increasing. Acid rain on the U.S. East coast reduced as a result. 73% of So2 emissions are from power plants , 20% for other industries. If you compare the ~ 19 pounds of So2+ NOx to the 2,249 lbs. of Co2 emitted per MWh of energy produced in power plants you can get a rough approximation of So2+NOx to Co2 at 1%. Not counting lesser sources. So just ballpark says 99% of ocean acidification is from Co2 emissions. You are a chemist so you can figure this out yourself. Co2 emissions have gone up from~ 22.5 billion tons( gt ) to ~ 32 gt 1990-2012. That is what is causing ocean acidification.
Yet while acidity is increasing in the more saline regions of the bay, the opposite is happening in the less saline waters, according to the study. Lead author of the study, Dr. George Waldbusser of Oregon State University, said “The regional changes in acidity revealed in our analysis are greater than what could be caused by increasing atmospheric carbon dioxide alone.”
The scientists believe that the diversity in acidity levels within the bay waters causes significant changes in the estuary's ecosystem. Nutrients from sewage systems and agricultural runoff promote an increase in phytoplankton in the upper bay. As these plants grow they absorb large amounts of carbon dioxide, resulting in less acidic waters in those regions. At the same time, when the phytoplankton are carried toward the ocean by the bay's currents, they are consumed by bacteria and animals that then release the carbon dioxide taken up the by phytoplankton. This stays in the water making it more acidic.
"does the carbon delivered to the ocean get quickly converted --- or is there a fraction that enters a longer term carbon sink?"Good Question(s). Hopefully they'll follow-up in future research.
A new paleoclimate study in Science suggests that climate sensitivity in the arctic is even higher than previously thought, and that the GIS was likely to have frequently been in an almost ice free state.
' “One of our major findings is that the Arctic was very warm in the Pliocene [~ 5.3 to 2.6 million years ago] when others have suggestedatmospheric CO2 was very much like levels we see today. This could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier models,” the authors state. '
Press release:
http://www.umass.edu/newsoffice/ice-free-arctic-may-be-our-future-say-umass-amherst-international-researchers (http://www.umass.edu/newsoffice/ice-free-arctic-may-be-our-future-say-umass-amherst-international-researchers)
See this excellent talk for a presentation of the results:
http://www.youtube.com/watch?v=YxbOSB7zDgY&feature=player_embedded (http://www.youtube.com/watch?v=YxbOSB7zDgY&feature=player_embedded)
This latest paper by Hauri et al describes how conditions will change here along the coast of California over the next 30-40 years.
there are 3.1 billion tons of extra carbon being added from the atmosphere. Since carbon dioxide is a very stable compound, it will stay in the atmosphere for many years. If we assume that this same kind of flux will be more or less maintained from now until the end of the century (the “end of now” time-frame that I talk about in my book), the atmospheric concentrations of carbon will grow by close to 50%. This is a major difference that directly affects our energy balance with the sun.
3.1 billion tons is less than half of what we emit into the atmosphere (red broken arrows in the picture). The difference means that both the earth and its oceans have now become net “sequesters,” or absorbers of the excess carbon dioxide that we produce. Vegetation and soil, in the form of enhanced growth because of the carbon dioxide that fertilization contributes, and areas of the ocean that absorb carbon dioxide, contribute as well. As the temperature rises, the capacity of these methods of compensation is expected to decrease, until they reach the point where both the earth and our oceans no longer absorb the carbon dioxide, but instead reverse themselves to be net emitters. Some would call this a “tipping point.”
This makes us part of the physical system that we investigate, and negates, at least in my mind, the option of waiting with remedies until the consequences of these changes are absolutely certain. Science tells us that the danger exists, so the remedies should be approached as an insurance premium.
Here is some of the latest news on both the politics and science on California Current acidification.
"Here on the California coast, deep water rises to replace surface water driven offshore by seasonal winds. Ironically, the upwelling that fuels the biological bounty of the California Current brings acidified water toward the surface. Recent computer models predict that conditions here will reach a critical point for shell formation in mollusks and other marine creatures by 2050."
http://baynature.org/articles/ocean-acid-trip-hidden-harm-climate-change/ (http://baynature.org/articles/ocean-acid-trip-hidden-harm-climate-change/)
The ocean could handle all the fossil fuel carbon we could throw at it if it were released over a 100,000 timeframe. It can't handle 5,000 giggatonnes of carbon in 300 or even a 1000 years however. 2000 years to burn all the fossil fuel reserves would still result in acidified oceans and extinctions .
The ocean could handle all the fossil fuel carbon we could throw at it if it were released over a 100,000 timeframe. It can't handle 5,000 giggatonnes of carbon in 300 or even a 1000 years however. 2000 years to burn all the fossil fuel reserves would still result in acidified oceans and extinctions .
Ccg, If I could venture an educated guess I would think the shift in ph by 2050 will begin to have its largest effects in the North Pacific and Arctic waters first with surface pH reduction to 7.9 or less.The Antarctic circumpolar waters should be close behind by ~ 2060. The entire west coast of North America will also be ( at least seasonally ) seeing surface pH at levels at or below 7.8 with extreme conditions during strong upwelling periods at levels down to 7.4. The Humboldt current will probably see similar extremes but I am not as familiar with those waters .Upwelling in the eastern tropical pacific is where the oldest waters in the world ventilate( back into the atmosphere ) so at least in tropical waters these are going to be the first tropical waters seeing a large shift relative to world averages. Indonesia and the Indian ocean next. The North Atlantic is one of the last places where O/A will get to similar pH levels. The saturation horizon is very deep in the Atlantic and although it is shoaling about 4 meters per year( maybe the fastest anywhere ) it will take longer to reach the point where surface upwelling can bring it up, unlike the pacific northwest where the saturation horizon is naturally much shallower. The aragonite saturation horizon is beginning to shoal upon the shelf waters of the Iceland Sea but I haven't heard of surface conditions anything like current conditions in Oregon and Washington state. Fiords with sills that trap waters masses I think are also problem spots but they do not represent the general conditions of the North Atlantic.
While the benthic marine communities surrounding the vents are typical of Mediterranean rocky reefs (i.e., diverse communities with abundant calcifying organisms) the communities directly adjacent to the vents are dominated by fleshy algae and devoid of calcifying organisms such as sea urchins, gastropods, and coralline algae.
Canadian, French and US researchers from the INRS have been studying the methane and greenhouse gas emissions in small thaw ponds, concluding that the emissions could have a significant climate impact.http://www.natureworldnews.com/articles/4972/20131118/ponds-canadian-arctic-release-significant-greenhouse-gasses.ht (http://www.natureworldnews.com/articles/4972/20131118/ponds-canadian-arctic-release-significant-greenhouse-gasses.ht)
"We discovered that although the small shallow ponds we studied represent only 44 percent of the water-covered surface in a Bylot Island valley, they generate 83 percent of its methane emissions," said Karita Negandhi, a water sciences doctoral student at the INRS's Environment Research Center.
...with the loss of sea ice, the Arctic Ocean is becoming more of a carbon sink
...
a somewhat paradoxical effect: A few Arctic regions where waters were warmest were actually less able to store carbon. Instead, these regions—such as the Barents Sea, near Greenland—were a carbon source, emitting carbon dioxide to the atmosphere.
It may, and in general, a warmer Arctic Ocean is likely to absorb more CO2 than a colder, icier one.
What she found, iirc, was that storms cause more methane to be released into the atmosphere from the water, exactly because of the foaming that waves produce. But perhaps I mis-interpreted you or her.
This is a sad day for me. It isn't just a loss for fishermen, it is a harbinger for things to come. The wind has arrived from the storm clouds I saw on the horizon ten years ago. Now the sea will test our mettle. Give us strength.Some will be on the front lines, slapped down by climate change first. I'm sorry that you are one of them, considering the efforts you've put into calling attention to it and developing a new paradigm.
They found that extra carbon dioxide in the atmosphere meant more input into the soil – nearly 20% more – but it also meant more turnover, up by more than 16%.
So if more went in, more was released, because the teeming microscopic fauna that inhabit the soil, recycle nutrients and redistribute plant nourishment also became more active.
“Our findings mean that nature is not as efficient in slowing global warming as we previously thought,” said Dr van Groenigen. “By overlooking this effect of increased CO2 on soil microbes, models used by the Intergovernmental Panel on Climate Change may have overestimated the potential of soil to store carbon and mitigate the greenhouse effect.”
Bruce Steele August 13, 2014.Well continue to keep us posted.
"So you my friends get to watch my struggles"
Jack, It is good to see you back. I am in complete agreement that to date fishing pressure can be held responsible for both a decline in catch rate as well as size of the larger ( older ) fish caught in a lot of areas. Local traditional fish management methods can be very effective at managing and maintaining stocks and the Pacific coast is a pretty good example of what success looks like if your looking for good examples of effective fish management. There are plenty of examples where it has failed however and there are plenty of reasons why including terrestrial inputs of fertilizer and sewage, increased marine mammal numbers, invasive species, and habitat modifications.A bit of offtopic: very well said, Bruce! Much pleasure to read (despite the subject being tragic) thoughts of a wise man. Prosit!
I have spent a good part of my life in meetings with other fishermen and government regulators trying to manage fish resources and for the most part when honest fishermen and dedicated managers work at it we can do a pretty good job maintaining the health of fish stocks and maintain financially viable fisheries. Maybe sometimes fish aren't as big as they used to be but that isn't the only measure of a healthy stock and if it is important upper size limits can be a tool in your management bag to address it.
I have come to the decision however that no amount of regulating local fish populations will be effective or sufficient if that management stops at the waters edge. Acidification and hypoxia are problems created on land and if we are going to save the oceans then changing how seven billion people go about their daily lives is critical. I was a fairly successful fish manager but providing answers for how we actually change 7 billion people is quite a challenge. It is far to easy for people to blame fishermen , wash their hands, and walk away. We need answers and not scapegoating. The Arctic Ocean looks like it will melt out some summer within our lifetime. It's melting will change weather patterns and food production for an overpopulated planet but changing the acidity of the oceans will outlive the damage we have done to the cryosphere. A hundred thousand years of hell for calcifiers, huge numbers of extinctions, and a compromised carbon sink is our collective contribution should we fail. Big fish - Small fish seems kinda minor in comparison .
...Ah, this really depends on how you define "better", though.
None of that darkness however should immobilize our efforts at building a better mousetrap.
So here we are.
F.Tnioli, Again I agree with what you have to say. I think many people have some notion of the "bottleneck" or "darkness" ahead but when that will come is more difficult to predict than an ice free September at 90 degrees north. I don't know if it's because I am contrary, prescient, or just a little thick but I have a bit of a primitivist bent myself. I have mentioned before that I believe there are still residual examples of societies ( tribes ) living within the resource limits of their local habitat. I haven't had the desire to go join one of these( existing ) groups and I haven't ever met anyone who tried. Forming some modern equivalent would require more than an acceptance of a primitive tool-set , it would require the social structure that would cement a group together. I think a lot about the tools,and techniques for food production but unless the " bottleneck " happens while I am alive I doubt anyone feels like helping me in the field and without that whatever I figure out will die with me. Short of getting experience before times get tough seems like a lot of people will be trying to figure this out in very difficult times. Resources even for a primitive existence aren't going to be at hands reach and sourcing the raw materials will require free movement. So getting through the bottleneck with your tribe and tool-set intact will require a lot of pre-planning and very good local knowledge of resources.We are doing offtopic here, but i sincerely hope that moderators will allow us to continue, considering that 1) what we discuss is actually important, 2) we arrived at it organically from discussing the topic, and 3) some few other people may find our here discussion useful for themselves.
So to some up, existing primitive societies and recreated versions will in my opinion have an advantage in a fast crash of civilization. Not many people want to go there voluntarily so likely very few will have the skill-set necessary to relearn what we walked away from a long time ago. Simple ain't easy. Getting along is part of that skill-set.
I would be interested in how you think Russians view primitive options? Is there anyone living years in their dacha pursuing off grid locally sourced survival? Are there groups? Is the thought of a very simple life appealing to many people there?
P.S. This is the carbon cycle page but entertaining solutions is as important or more important than documenting the disaster. So thank you F.Tnioli
any chance some methanogen is using this to break methane, and in the process creating the huge amounts of carbon tet NASA just found ?"This"? I doubt. Methane - CH4, - doesn't require complex catalysts to be "broken". Simple oxygen will do. http://en.wikipedia.org/wiki/Methanotroph (http://en.wikipedia.org/wiki/Methanotroph) , you know. As for their ability to produce carbon tetrachloride (i guess this is what you refer to as "carbon tet"), - i think that certain ferments/enzimes/whatever are indeed used by those bacteria, but it's nothing really special. The strength of chemical bonds within CCl4 molecula is much, much higher than strength of bonds within CH4 molecula, since both carbon and hydrogen are nearly neutral elements, while chlorine is highly electronegative element. Granted, HCl forms somewhat easier than CCl4 (if i remember my inorganic chemistry course right), but the differense is not that big, significantly forming one instead of the other should be not a huge problem for a living cell. The only moment where the bacteria really needs some good catalyst (enzyme, ferment, whatever) - is when it "extracts" chlorine from (overabundant in the ocean) NaCl molecula. Frankly, this is extremely common biochemical process, which happens even within human body, and provides Na+ and Cl- ions for lots of important biochemical processes. For all animals and humans, the enzyme "responsible" for the key part of the process - is http://en.wikipedia.org/wiki/Na%2B/K%2B-ATPase (http://en.wikipedia.org/wiki/Na%2B/K%2B-ATPase) , and i wouldn't be surprised if those bacteria use very same thing as well. I suspect that the enzyme is probably nearly as old as cellular life itself, - i.e. some 1+ billion years, eh.
There dosn't seem to be many other mechanisms availible, but they have found bacteria using vanadium and iron and cobalt. maybe not that big a stretch
http://m.phys.org/news/2014-08-benzene.html (http://m.phys.org/news/2014-08-benzene.html)
..."Escaping" from the reality? It's the path of many. Must admit, i have my ways to do it too, and i do it rather often. "Only humans", eh. It helps to remain (relatively) sane, perhaps, - but it doesn't help with the big picture. I know it, i bet you know it, and probably it can't be changed, but still i feel... irritation about it. Equally so about myself and about others whenever i see them performing some "escaping", whatever form it gets.
Total anthropogenic Co2 emissions were, like my article said, in the range of 500 gt Co2 back then but cumulative totals will be very close to 1000 gt Co2 by 2020. ...
"climate fatigue"--that's funny. We don't have any idea what climate fatigue is yet.
I too get tired of the feel good summary. Tell me the truth, doc, and let me plan around that.
;D"climate fatigue"--that's funny. We don't have any idea what climate fatigue is yet.
I too get tired of the feel good summary. Tell me the truth, doc, and let me plan around that.
you want answers?
....
well,
you asked.
Jai, Under that scenario the average surface ocean pH will be reduced to 7.3 by 2300( Caldeira 2003 ) I don't think you get 200+ meters sea level so maybe you could give a reference. Not that 200 feet or 200 meters will make any difference to whatever scraps of " Modern civilization " remains. We either change course now or your prognosis seems valid, not that national geo would print it. You realize most people think we're nuts.
Forming some modern equivalent would require more than an acceptance of a primitive tool-set , it would require the social structure that would cement a group together.
I think a lot about the tools,and techniques for food production but unless the " bottleneck " happens while I am alive I doubt anyone feels like helping me in the field and without that whatever I figure out will die with me. Short of getting experience before times get tough seems like a lot of people will be trying to figure this out in very difficult times. Resources even for a primitive existence aren't going to be at hands reach and sourcing the raw materials will require free movement. So getting through the bottleneck with your tribe and tool-set intact will require a lot of pre-planning and very good local knowledge of resources.
P.S. This is the carbon cycle page but entertaining solutions is as important or more important than documenting the disaster. So thank you F.Tnioli
Their story - is exactly what happened when the dream of "getting back to nature" (which they had) was actually pursued in practice.
Global emissions of greenhouse gases jumped 2.3 percent in 2013 to record levels, scientists reported Sunday, in the latest indication that the world remains far off track in its efforts to control global warming.
The emissions growth last year was a bit slower than the average growth rate of 2.5 percent over the past decade, and much of the dip was caused by an economic slowdown in China, which is the world’s single largest source of emissions. It may take an additional year or two to know if China has turned a corner toward slower emissions growth, or if the runaway pace of recent years will resume.
In the United States, emissions rose 2.9 percent, after declining in recent years.
The new numbers, reported by a tracking initiative called the Global Carbon Project and published in the journal Nature Geoscience, came on the eve of a United Nations summit meeting meant to harness fresh political ambition in tackling climate change. Scientists said the figures showed that vastly greater efforts would be needed to get long-term global warming within tolerable limits.
“You can no longer have some countries go first and others come in later, because there is no more time,” said Glen P. Peters, a scientist at the Center for International Climate and Environmental Research in Oslo, who helped compile the new numbers. “It needs to be all hands on deck now.”
Per the linked reference (& two associated attached images), both RCP 2.6 & 4.5, are highly dependent on the use of bioenergy and carbon capture storage (BECCS), which is highly uncertain technology for reducing CO2 in the atmosphere.
Per the linked reference (& two associated attached images), both RCP 2.6 & 4.5, are highly dependent on the use of bioenergy and carbon capture storage (BECCS), which is highly uncertain technology for reducing CO2 in the atmosphere.
These projections do not include CO2 and methane release from melting permafrost either.
Andrew Doxey and Josh Neufeld, professors in Waterloo’s Department of Biology, point out that the discovery has implications for climate change because the availability of vitamin B12 may control how much or how little biological productivity by phytoplankton takes place in the oceans. Phytoplankton remove carbon dioxide from the atmosphere much like plants and trees.
Climate change: Models 'underplay plant CO2 absorption
http://www.bbc.com/news/science-environment-29601644 (http://www.bbc.com/news/science-environment-29601644)
Waterloo discovery: Tiny ocean organisms are big B12 producers
https://uwaterloo.ca/stories/waterloo-discovery-tiny-ocean-organisms-are-big-b12-0 (https://uwaterloo.ca/stories/waterloo-discovery-tiny-ocean-organisms-are-big-b12-0)QuoteAndrew Doxey and Josh Neufeld, professors in Waterloo’s Department of Biology, point out that the discovery has implications for climate change because the availability of vitamin B12 may control how much or how little biological productivity by phytoplankton takes place in the oceans. Phytoplankton remove carbon dioxide from the atmosphere much like plants and trees.
Vast amounts of methane appear to be leaking undetected from Australia's biggest coal seam gas field, according to world-first research that undercuts claims by the gas industry.
Testing inside the Tara gas field, near Condamine on Queensland's Western Downs, found some greenhouse gas levels over three times higher than nearby districts, according to the study by researchers at Southern Cross University.
The study has potential national consequences because last week's energy white paper forecast a massive expansion of Australian coal seam gas drilling, and called for environmental objections to be removed to make large-scale gas extraction easier
Methane, carbon dioxide and other gases appear to be leaking up through the soil and bubbling up through rivers at an astonishing rate, the researchers said.
"The concentrations here are higher than any measured in gas fields anywhere else that I can think of, including in Russia," said Damien Maher, a biochemist who helped conduct the tests. "The extent of these enriched concentrations is significant."
By the end of this year, more than half of all industrial emissions of carbon dioxide since the dawn of the Industrial Revolution will have been released since 1988 — the year it became widely known that these emissions are warming the climate.
I recently learned this startling fact from my colleague Richard Heede at the Climate Accountability Institute. Heede drew upon historic estimates of annual global carbon emissions from fossil fuel burning and cement manufacturing by the U.S. Department of Energy’s Carbon Dioxide Information Analysis Center (CDIAC) and the 2014 annual update on the global carbon budget and trends published by the Global Carbon Project (GCP), an international scientific research consortium studying the global carbon cycle.
The GCP estimates that in 2014, we will release a record 37 gigatons (GT) of carbon dioxide to the atmosphere from burning coal, oil, and natural gas, and manufacturing cement. That’s a 2.5 percent increase over emissions in 2013, itself a record year. This brings the total industrial carbon dioxide emissions since 1751 to an estimated 1480 Gt by the end of this year. And, remarkably, more than half of these emissions, 743 Gt, or 50.2 percent, have released just since 1988.
Burning of 5000 Gt C of potentially available fossil fuel reserves would lead to a higher long-term CO2 level in the atmosphere and a reduced fractional ocean uptake capacity in comparison to, e.g. burning only 1000 Gt C (Archer, 2005).
The impact on societies and life even after 100 000 years depends, thus, on our behaviour concerning usage of fossil fuel reserves today. This fact as well has to be taken into account for greenhouse gas emission reduction strategies.
The following link leads to a video showing a comparison of direct atmospheric CO2 measurements vs direct measurement of radiative forcing, and they track very closely with seasonal and long-term trends:
https://www.youtube.com/watch?v=5yq1MFUQ0fI (https://www.youtube.com/watch?v=5yq1MFUQ0fI)
Microbes can breathe oxygen like you and I, but when it goes away, they can breathe other things, such as nitrogen," she said. Understanding how these reactions work in low oxygen zones is important. As the ocean warms up, those zones may expand.
uptake rate, kS, “declined over 1959–2012 by a factor of about 1/3, implying that CO2 sinks increased more slowly than excess CO2.”
I've been very slowly making my way through several threads, I'm probably months of reading behind the level of debate frequently occurs on here. I have a question that is pethaps overly simple and this seems the best thread to ask it in. If carbon or the amount of carbon remains in the atmosphere for 500-1000 years and is causing warming for all, or at least a significant amount of time; is reducing emissions actually going to achieve much? Given the amount we have already spewed out? I mean isn't there already enough to heat the atmosphere by a number of degrees C. and won't that increase remain for that 500-1000 years?
Edit- and in that case aren't we fucked, sooner or later, probably sooner?
Thanks, so making civilisation "carbon neutral" is only a first step? I'm ambivalent about geo engineering, it sounds like a great way to make things worse. I've read too many scientists say its too risky.
"We typically think of temperature and other physiochemical factors as being critically important in determining the bacterial processing of diatom detritus and how deep it sinks in the ocean, but this work shows that the molecular composition of 'infochemicals' really matters," said Bidle.
. A recent report by scientists at Oregon State University, however, found that when chemicals emitted by plant roots interact with minerals in soil, it can cause carbon to break free. This exposes the carbon to decomposition by microbes in the soil, which pass it into the atmosphere as carbon dioxide. As the climate warms, the scientists found, more carbon dioxide in the atmosphere will stimulate the growth of plants, which will in turn stimulate the production of the root compounds that breakdown carbon and soil minerals.
But a December 2014 study of Pacific oyster and Mediterranean mussel larvae in Nature Climate Change determined that “the earliest larval stages are directly sensitive to saturation state, not carbon dioxide (CO2) or pH” (acidity). So what matters most is how much calcium carbonate is in the ocean water relative to the total amount it could hold.I am not sure what type of saturation to they speak about, is it Ca2+ ?
maybe it's just more numbers, one more species headed for extinction, one more million year old species getting rubbed out by manunkind.
ASLR, Neither the link you provide nor the one that makes similar claims that sigmetnow posted provide a shred of scientific evidence about their actual sources. So if you prefer to repeat crap put out by an NGO like WWF who is in the business of selling scare tactics for the benefit of their coffers I suppose me telling you that here on the US west coast we don't have Any overfishing currently taking place because we have regulated most fishing into nonexistence while at the same time importing over 90% of all seafood from countries with fewer or nonexistent fisheries protections. The few fishermen who still ply US waters and have struggled to both protect and enforce the most stringent fishery regulations in the world are thrown under the bus while corporate and NGO's interests cash in at the bank.
My last post was about the upcoming Extinction of a sea urchin species that everyone is collectively promoting with BAU but there isn't any profit for WWF to fight that battle so they fly around the world, push regulations by expensive lawyers in DC that ultimately outsource the problems and the carbon footprint of their own actions.
There isn't one fish species in the world you can show me that went extinct due to fishermen. So if everyone wants to get righteous maybe they could walk a mile I my shoes and watch as good efforts get you spit in the face.
This rant is driven by current regulations that will be putting more of my friends out of business in the near future and not just the garbage printed in the above articles. Hard to watch and always amazing to see two different standards for science on this otherwise excellent forum. If you want fish science I could provide it but maybe pushing buttons makes some people feel good about themselves, nothing personal.
ASLR, You are the last person I would choose to offend. I live two lives perhaps and I am afraid i let the politics of my private life bleed over onto this site earlier today. Fish politics is very rough and
tumble and I am afraid watching as good men who have done an honest and honorable job at regulating their individual fisheries go down to dirty politics makes me hot under the collar. I will later put a link to a new web-page that I have access to but is currently embargoed. There you can read both the controversial papers like the one you linked earlier with a peer reviewed comment section by some of the best fisheries scientists in the world. I don't know how useful it will be in a country that is smitten by the likes of Donald Trump .
We have to maintain a higher standard however . Not a high bar .
Yes I agree the next couple generations is going to be handed a bag of .... I will struggle on and try to help avoid contributing to our collective demise. The carbon page and the 40,000 hits it has received is an intellectual attempt at describing some rather harsh inevitable outcomes as well as other even worse outcomes if " the Donald" and his irk hold sway.
Jai, I don't agree but I don't want to bog down the "carbon cycle page" If someone thinks we need a fishing page charge on.
The top metre of the world’s soils contains three times as much carbon as the entire atmosphere. This means that losing carbon from the soil can quicken the pace of human-caused climate warming.http://www.carbonbrief.org/alpine-soils-storing-up-to-a-third-less-carbon-as-summers-warm (http://www.carbonbrief.org/alpine-soils-storing-up-to-a-third-less-carbon-as-summers-warm)
A new paper, published today in Nature Geoscience, finds this is already happening in the forests of the German Alps. Soils there are losing carbon as summer temperatures rise, the researchers say.
In the last three decades, soil carbon across the German Alps has decreased by an average of 14% – and by as much as 32% for certain types of soils.
The findings might be a sign of how soils could amplify warming in future, other scientists say.
Prof Pierre Friedlingstein, chair of mathematical modelling of climate systems at the University of Exeter, suggested the estimate that there are five years worth of current emissions left before we exceed the carbon budget to stay under 1.5C is too pessimistic. Accounting for the fact that the cumulative warming per unit of carbon dioxide observed recently is lower than in the majority of climate models extends the 1.5C budget timeline to 20-30 years.
There was conference “1.5C conference on climate change”, organised by the Environmental Change Institute at the University of Oxford. Carbon Brief reports a view that carbon budgets are much too pessimistic (https://www.carbonbrief.org/day-two-at-the-1-5-c-conference-on-climate-change-in-oxford)QuoteProf Pierre Friedlingstein, chair of mathematical modelling of climate systems at the University of Exeter, suggested the estimate that there are five years worth of current emissions left before we exceed the carbon budget to stay under 1.5C is too pessimistic. Accounting for the fact that the cumulative warming per unit of carbon dioxide observed recently is lower than in the majority of climate models extends the 1.5C budget timeline to 20-30 years.
Is this realistic? Is there any published material, peer-reviewed or otherwise?
[1] In the video, Professor Corrinne Le Quere says [to keep within 1.5°C] it is necessary to be “completely de-carbonising the economy in just a few decades."
Earlier this year Carbon Brief said (https://www.carbonbrief.org/analysis-only-five-years-left-before-one-point-five-c-budget-is-blown) “Analysis: Only five years left before 1.5°C carbon budget is blown”. There is a big difference between “a few decades” and five years.
[2] Corrine also says “Global emissions have stalled in the past few years”. Apart from the fact that “stalled” is nowhere good enough, this reduction is not yet seen in the increasing concentrations of CO2 in the atmosphere(2).
Before the science talks, Dr Anna Pirani, head of the IPCC’s Working Group 1 Technical Support Unit, reminded everyone of the short timeline they’re working to. To be assessed in the IPCC’s special report on 1.5°C, papers must be submitted by October 2017 and accepted by April 2018.
What are we to believe about the remaining budget?
P.S. Five years means that we need degrowth (http://www.brusselsblog.co.uk/green-growth-or-degrowth/). The politics of that are awful.
Two or three decades is a lot of long grass to hide in.
In any case, the results suggest the process can take a lot longer than scientists previously assume — up to thousands of years, instead of just tens or hundreds. This means that previous research may have significantly overestimated how much carbon the world’s soil can store away throughout the rest of the century. In fact, the new study suggests that, worldwide, soil’s carbon sequestration potential this century may only be half what we thought it was.
There’s been no deceleration. Whatever emissions reductions have happened, haven’t yet slowed down the rise of CO2.
CO2 concentrations may be subject to lags or effects such as El Nino. Are these the explanations or are carbon feedbacks kicking in (reducing our remaining carbon budget)?
CO2 concentrations may be subject to lags or effects such as El Nino.
The linked reference & associated following linked article indicate that from 2002 to 2014 there was a temporary pause in the rate of atmosphere carbon dioxide growth rate (down to around 2ppm per year, see the attached image) associated with an increase in terrestrial carbon uptake. While that is nice, it appears that the pause is temporary in nature as from October 2015 to October 2016 atmospheric carbon dioxide at Mauna Loa increased by 3.28ppm. Furthermore, Hansen has warned that carbon temporarily sequestered in terrestrial organic material is subject to future release with continued global warming
Keenan et. al. (2016) "Recent pause in the growth rate of atmospheric CO₂ due to enhanced terrestrial carbon uptake", Nature Communication, doi:10.1038/ncomms13428.
http://www.nature.com/articles/ncomms13428 (http://www.nature.com/articles/ncomms13428)
See also the associated article entitled: "Rise in atmospheric CO2 slowed by green vegetation"
http://www.bbc.com/news/science-environment-37909361 (http://www.bbc.com/news/science-environment-37909361)
Extract: "The growth in the amount of CO2 in the Earth's atmosphere has been slowed by the increased ability of plants to soak up the gas.
…
"We have a huge amount of vegetation on the Earth and that was being fertilised by CO2 and taking in more CO2 as a result."
Another important element in the story is the impact of a hiatus in global temperature increases on the behaviour of plants. Between 1998 and 2012 temperatures went up by less than in previous decades. This has impacted the respiration of vegetation.
"The soils and ecosystem are respiring so as temperatures increase they respire more, releasing more CO2 into the atmosphere," said Dr Keenan.
"In the past decade or so there hasn't been much of an increase in global temperatures, so that meant there wasn't much of an increase in respiration and carbon release so that was fundamentally different in the past decade or so compared to previous periods."
One consequence of a warming world that has been expected to increase was the number of droughts around the world. However, this new study suggests that, on a global scale, there has been little or no change in the prevalence of drought over recent decades.
Overall though the slowdown caused by vegetation hasn't stemmed the total rise of carbon which has now passed the symbolically important level of 400 parts per million (ppm) in the atmosphere."
Edit:
See also the following linked article entitled: "How scientists predicted CO2 would breach 400ppm in 2016"
https://www.carbonbrief.org/how-scientists-predicted-co2-would-breach-400pm-2016 (https://www.carbonbrief.org/how-scientists-predicted-co2-would-breach-400pm-2016)
Extract: "If the world’s nations are serious about halting global warming, the rise in CO2 concentrations also needs to cease. This means the annual change in CO2 concentration – generally 2ppm per year, and around 3ppm this year – needs to become zero. That is, the sinks need to balance the sources. Based on our current understanding of the carbon cycle, this task will be harder the longer we leave it."
Tamino strongly refuted this in a great post (he's a stats guy):
https://tamino.wordpress.com/2016/11/11/another-pause-claim/ (https://tamino.wordpress.com/2016/11/11/another-pause-claim/)
Doesn't look like a pause to me either. Looking pretty silly after the last two years of data showing 3 and (likely) 3.5 ppm of rise. Some of that is due to ENSO, but given how large those numbers are, it certainly doesn't fall in with a pause theory.
Tamino strongly refuted this in a great post (he's a stats guy):
https://tamino.wordpress.com/2016/11/11/another-pause-claim/ (https://tamino.wordpress.com/2016/11/11/another-pause-claim/)
Doesn't look like a pause to me either. Looking pretty silly after the last two years of data showing 3 and (likely) 3.5 ppm of rise. Some of that is due to ENSO, but given how large those numbers are, it certainly doesn't fall in with a pause theory.
As Gavin Schmidt likes to point-out, attribution without a fully calibrated advanced Earth System Model is impossible. So no matter how sincere Tamino's statists may be, they cannot rule-out the probability that terrestrial plants may be temporarily soaking-up more carbon dioxide than they were a few decades ago. If so things could become much worse for us all once our currently unprecedented rate of climate change starts to overstress both the terrestrial and oceanic plants.
The linked article discusses how the impacts of ocean acidification may be more widespread and may last longer (multiple centuries) than most people think:
http://www.latimes.com/science/sciencenow/la-sci-sn-phytoplankton-acidic-oceans-20160708-snap-story.html (http://www.latimes.com/science/sciencenow/la-sci-sn-phytoplankton-acidic-oceans-20160708-snap-story.html)
It's possible, but there's no direct evidence for it. I think that was the point of Tamino's article. It was perplexing to see a 12-year trend being used in a peer-reviewed paper, especially since we regularly lambast deniers for using such short intervals for spurious claims about global temperature trends. There's not even any evidence for a slowdown in the rate of acceleration.
Climate scientists presume that the carbon cycle has come out of balance due to the increasing anthropogenic emissions from fossil fuel combustion and land use change. This is made responsible for the rapidly increasing atmospheric CO2 concentrations over recent years, and it is estimated that the removal of the additional emissions from the atmosphere will take a few hundred thousand years. Since this goes along with an increasing greenhouse effect and a further global warming, a better understanding of the carbon cycle is of great importance for all future climate change predictions. We have critically scrutinized this cycle and present an alternative concept, for which the uptake of CO2 by natural sinks scales proportional with the CO2 concentration. In addition, we consider temperature dependent natural emission and absorption rates, by which the paleoclimatic CO2 variations and the actual CO2 growth rate can well be explained. The anthropogenic contribution to the actual CO2 concentration is found to be 4.3%, its fraction to the CO2 increase over the Industrial Era is 15% and the average residence time 4 years.
... How can he possibly assume that all carbon sinks will perfectly accommodate the increase of CO2 in the atmosphere? How can all carbon sinks scale linearly with carbon concentration? Magic? ...
how does he account for the historic increase in CO2 from 270 ppm's to the 400ppm's we have now? Magic again? Natural variability? arghh.
[Hermann Harde's] claim goes like this:
(A) Predictions for the Global Warming Potential (GWP) by the IPCC express the warming effect CO2 has over several time scales; 20, 100 and 500 years.
(B) But CO2 has only a 5 year life time in the atmosphere.
(C) Therefore CO2 cannot cause the long term warming predicted by the IPCC.
This claim is false. (A) is true. (B) is also true. But B is irrelevant and misleading so it does not follow that C is therefore true.
source: Skeptical Science (https://www.skepticalscience.com/co2-residence-time.htm)
Oh dear me. Yes, it’s nonsense. But apparently it’s an “Invited” paper? (I’ve never heard of that either). Some questions are going to be raised about the peer review and editorial process here… – gavin]
I will be here , I will try to describe what I see , I will accept my failures and try to remedy them.
"I live for being wrong," said Lajoie. "That's where we learn."Yep. (http://forum.arctic-sea-ice.net/index.php?action=post;msg=110914;topic=179.850) What more a human can do ?
The results increase the most recent global estimates of CO2 emissions from rivers and lakes by almost 50%, with potentially huge implications for global climate policy
ASLR, We are seeing some of the lowest surface water pH readings here along the US West Coast.
Thanks Wili and Terry, That line "cnidarian nightmares "rolls off the tongue better with the proper pronunciation of CNIDARIA. The C is silent.
https://sesquiotic.wordpress.com/2015/11/28/cnidaria-cnidarian/
More failures of major carbon sinks, which are now turning into sources, this time tropical forests:Also a major contribution to the 6th Mass Extinction currently underway and which at the current rate of progress will wipe out virtually all vertebrate life on earth by mid-century.
Alarm as study reveals world’s tropical forests are huge carbon emission source
Forests globally are so degraded that instead of absorbing emissions they now release more carbon annually than all the traffic in the US
https://www.theguardian.com/environment/2017/sep/28/alarm-as-study-reveals-worlds-tropical-forests-are-huge-carbon-emission-source (https://www.theguardian.com/environment/2017/sep/28/alarm-as-study-reveals-worlds-tropical-forests-are-huge-carbon-emission-source)
" ... wipe out virtually all vertebrate life on earth by mid-century. "
Any references ?
sidd
Thanx for bringing up the Ceballos paper, it had slipped my mind. But it does not support the claim that virtually all vertebrates will be gone by midcentury. Barring meteor impact or Siberian/Deccan Traps scale event I find the claim difficult.
sidd
Thanx for bringing up the Ceballos paper, it had slipped my mind. But it does not support the claim that virtually all vertebrates will be gone by midcentury. Barring meteor impact or Siberian/Deccan Traps scale event I find the claim difficult.
sidd
The Ceballos paper, along with many others, extrapolate the decline of other animal species due to human over-hunting and habitat destruction. Most of the talk about the sixth mass extinction refer to these causes. While we have taken many steps to stem overhunting and have worked to conserve several species, the destruction of many natural habitats is still progressing. These have much greater consequences for life than the actual carbon uptake of the forests.
" ... wipe out virtually all vertebrate life on earth by mid-century. "I repeat a post I put up some time ago and remembered to save.
Any references ?
sidd
The Ceballos paper, along with many others, extrapolate the decline of other animal species due to human over-hunting and habitat destruction. Most of the talk about the sixth mass extinction refer to these causes. While we have taken many steps to stem overhunting and have worked to conserve several species, the destruction of many natural habitats is still progressing. These have much greater consequences for life than the actual carbon uptake of the forests.
It is certainly a mistake to look at climate change in a vacuum, but just because there are many problems/stresses (e.g. over-population, resource depletion, pollution, warfare, systemic fragilities etc.) in the world today, doesn't that climate change won't be the 'straw that broke the camel's back'.
WOODS HOLE, Mass. — After 26 years, the world's longest-running experiment to discover how warming temperatures affect forest soils has revealed a surprising, cyclical response: Soil warming stimulates periods of abundant carbon release from the soil to the atmosphere alternating with periods of no detectable loss in soil carbon stores. Overall, the results indicate that in a warming world, a self-reinforcing and perhaps uncontrollable carbon feedback will occur between forest soils and the climate system, adding to the build-up of atmospheric carbon dioxide caused by burning fossil fuels and accelerating global warming. The study, led by Jerry Melillo, Distinguished Scientist at the Marine Biological Laboratory (MBL), appears in the October 6 issue of Science.
The total remaining emissions from 2017 to keep global average temperature below 2°C (800GtCO2) will be used in around 20 years at current emission rates
Net emissions for RCP2.6 are 824 Gt CO2 - for fossil fuel and cement. Adding in 180 Gt of CO2 from changes in land use for the period 2017 to 2100 give total CO2 emissions of 1004 Gt of CO2 – much larger than the 816 remaining CO2 quota. (Note: Wildfire emissions count as land use change emissions.)
The worse news is that World CO2 emissions are exceeding the emissions in the hypothetical numbers that are in the RCP2.6 CO2 scenario. CO2 emissions, including land use change, were 49.1 Gt CO2 in 2016, 11% more than in the RCP 2.6 scenario for that year.
HELP!
I've been looking at a PDF of the Carbon Project's Carbon Budget 2016 (http://www.globalcarbonproject.org/carbonbudget/16/files/GCP_CarbonBudget_2016.pdf). It has a graphic, Carbon quota for a 66% chance to keep below 2°C, with a sub-headingQuoteThe total remaining emissions from 2017 to keep global average temperature below 2°C (800GtCO2) will be used in around 20 years at current emission rates
This is the image:
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.brusselsblog.co.uk%2Fimg%2FCarbonQuota2017.jpg&hash=8d6552c9e28a873abad0edd6292eae18)
(How do I do inline images?) <use the img tags, or highlight the image link address and then press the img button in the editor above the comment (next to the f sign, middle row, under the italics button). If you click the 'modify comment' button for this comment, you can see what I did; N. Thanks; Geoff>
I have also downloaded some of the numbers for CO2 emissions from RCP 2.6. Have I got the following right?QuoteNet emissions for RCP2.6 are 824 Gt CO2 - for fossil fuel and cement. Adding in 180 Gt of CO2 from changes in land use for the period 2017 to 2100 give total CO2 emissions of 1004 Gt of CO2 – much larger than the 816 remaining CO2 quota. (Note: Wildfire emissions count as land use change emissions.)
The worse news is that World CO2 emissions are exceeding the emissions in the hypothetical numbers that are in the RCP2.6 CO2 scenario. CO2 emissions, including land use change, were 49.1 Gt CO2 in 2016, 11% more than in the RCP 2.6 scenario for that year.
These are only for CO2. Other climate pollutants are treated separately.
I got the 824 Gt CO2 emissions (2017 to 2100) from 889 Gt CO2 positive emissions (2017 to 2072) less 65 Gt CO2 negative emissions (20673 to 2100).
I'm not necessarily asking for a reworking of this (though that would be welcome) but is this result so unexpected that I must have misunderstood.
I thought RCP2.6 was our savior. Am I wrong?
Clear as mud?
CARBON BUDGETS AND RCP2.6
I've been looking at this further and been comparing the Global Carbon Project's Carbon Budgets for 2016 and 2015 and found another useful diagram. I had some confusion due to the fact that the diagram in the “2015 budget document” showed data to the end of 2014 but the similar diagram in the 2016 budget document showed data to the end of 2016 - moving on a year. Here are the diagrams, with a little bit of extra annotation.
A: From Carbon Budget 2015 (http://www.globalcarbonproject.org/carbonbudget/archive/2015/GCP_budget_2015_v1.02.pdf): Heading “The total remaining emissions from 2014 to keep global average temperature below 2°C (900 GtCO2 ) will be used in around 20 years at current emission rates”.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.brusselsblog.co.uk%2Fimg%2FCarbonQuota_endOf2014.jpg&hash=3f94e2c702e02431e14e47a3737ca4e0)
From Carbon Budget 2016 (http://www.globalcarbonproject.org/carbonbudget/16/files/GCP_CarbonBudget_2016.pdf): Heading “The total remaining emissions from 2017 to keep global average temperature below 2°C (800 GtCO2 ) will be used in around 20 years at current emission rates”.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.brusselsblog.co.uk%2Fimg%2FCarbonQuota_endOf2016.jpg&hash=30563902f76549f9e6c7ebdd51799d45)
I interpret the diagrams like this
1) “Total quota 3670”: 3670 Gt CO2 is 1000 GtC as per Allen et. al Warming caused by cumulative carbon emissions towards the trillionth tonne (http://www.nature.com/nature/journal/v458/n7242/abs/nature08019.html).
2) “Non-CO2 770”: It is assumed that the effect of non-CO2 pollutants will have a similar climate effect on the carbon buget to emissions of 770 Gt of CO2.
3) Emissions of CO2 from fossil fuels between the ends of 2014 and 2016 have reduced the remaining carbon budget by the difference between 1542 Gt CO2 (A) and 1465 Gt CO2 (B) ie. 77 Gt CO2. This is two years worth of fossil fuel and cement emissions (38.5 Gt CO2/year?).
4) Emissions of CO2 from land use change have reduced the remaining carbon budget by the difference between 542 Gt CO2 (A) and 533 Gt CO2 (B) ie. 9 Gt CO2. This is two years worth of fossil fuel and cement emissions (4.5 Gt CO2/year?).
5) The “total remaining CO2 quota” has reduced from 903 Gt CO2 to 816 GtCO2 i.e. by 87 GtCO2. That averages at 43.5 Gt CO2/year.
In (A) the remaining budget is split between future land use change and future fossil fuel and cement emissions. I'm not sure where the “Future LUC 138” comes from but I note that the numbers given in the RCP2.6 tables give “Other CO2 emissions”. These total 122 Gt CO2 between the end of 2016 and 2072. Year 2072 is the date that RCP2.6 goes into negative emissions fossil fuel and cement.
Taking 122 Gt CO2 off the “total remaining CO2 quota” at the end of 2016 gives 694 Gt CO2.
That's just over 91 tonnes CO2 each when it's spread over the world's population. Using this methodology, I think we may have about 25% extra budget to emit non-CO2 emissions. That would take us to 120 tonnes CO2e each.
The average UK citizen gets through that in about eight years – if we do the decent thing and measure emissions on a consumption basis rather than cheating and measuring on a production basis like our government does.
However, there's lots of reasons for thinking the climate situation is worse.
Anyway, according to my spreadsheet, RCP 2.6 runs out of the 816 Gt CO2 remaining budget in 2047 and that budget is for a 2°C rise in global temperature and we seem to be soaring way above RCP 2.6.
The research is tending to an ECS at the higher end of the range than assumed in these carbon budgets, plus they do not take into account feedbacks (soil carbon, clouds, albedo etc.), plus they underestimate the effect of methane, plus the land use numbers are highly suspect. Apart from that, these carbon budgets are really useful /sarc.
There is no carbon budget if we take any realistic view of things and/or use a better (i.e. much higher than 2 out of 3, even in Russian Roulette its 1 out of 6) probability of success.
It will be interesting to watch the UN IPCC attempt to keep the carbon budget story going when confronted with updated scientific findings.
1. Have wildfires been included in any scenarios for the future of our climate?
2. Why can’t representative carbon pathways be fed into climate models to tell us about the effects burning down forests, flying and eating beef?
3. How hard is (2)?
More failures of major carbon sinks, which are now turning into sources, this time tropical forests:Also a major contribution to the 6th Mass Extinction currently underway and which at the current rate of progress will wipe out virtually all vertebrate life on earth by mid-century.
Alarm as study reveals world’s tropical forests are huge carbon emission source
Forests globally are so degraded that instead of absorbing emissions they now release more carbon annually than all the traffic in the US
https://www.theguardian.com/environment/2017/sep/28/alarm-as-study-reveals-worlds-tropical-forests-are-huge-carbon-emission-source (https://www.theguardian.com/environment/2017/sep/28/alarm-as-study-reveals-worlds-tropical-forests-are-huge-carbon-emission-source)
Just had to log on to check if the rainforest-study had been mentioned here. This looks like the endgame to 4-6---12 °C above 1950s, is about to begin. It feels quite ok to be rather aged and childless.
It is certainly a mistake to look at climate change in a vacuum, but just because there are many problems/stresses (e.g. over-population, resource depletion, pollution, warfare, systemic fragilities etc.) in the world today, doesn't that climate change won't be the 'straw that broke the camel's back'.
Possibly. However, I think that any of those other causes could accomplish the decline (and eventually extinction) all by themselves.
It is certainly a mistake to look at climate change in a vacuum, but just because there are many problems/stresses (e.g. over-population, resource depletion, pollution, warfare, systemic fragilities etc.) in the world today, doesn't that climate change won't be the 'straw that broke the camel's back'.
Possibly. However, I think that any of those other causes could accomplish the decline (and eventually extinction) all by themselves.
Your point being?
That climate change will be a minor contributor to extinctions. Most plants and animals would be able to adapt to climate perturbations much easier that overhunting, pollution, or total habitat destruction.
Just had to log on to check if the rainforest-study had been mentioned here. This looks like the endgame to 4-6---12 °C above 1950s, is about to begin. It feels quite ok to be rather aged and childless.
4 children (1 adopted) and 1st grandchild on the way. It is sad and depressing.
It is certainly a mistake to look at climate change in a vacuum, but just because there are many problems/stresses (e.g. over-population, resource depletion, pollution, warfare, systemic fragilities etc.) in the world today, doesn't that climate change won't be the 'straw that broke the camel's back'.
Possibly. However, I think that any of those other causes could accomplish the decline (and eventually extinction) all by themselves.
Your point being?
That climate change will be a minor contributor to extinctions. Most plants and animals would be able to adapt to climate perturbations much easier that overhunting, pollution, or total habitat destruction.
No matter where I go, habitats are degraded not because of climate change but because of mechanical and chemical destruction through agriculture. Then add expanding cities and hunting/ fishing and you have the perfect storm for extinctions.
Without all the human impact, most species would just migrate in the light of a warming climate.
Re: " ... most and probably all of the previous mass extinction events were driven primarily by global warming. "
I am not sure this is true. Cites ?
sidd
Sorry, got cut off.
1. Ordovician event (440 Myr ago) is thought to have been cause by periods of intense glaciation and recession.
2. Devonian event (360 Myr ago) by global cooling, likely caused by an asteroid impact or volcanism.
3. Permian event (250 Myr ago) by the eruption of a Siberian volcano (although this may have been ultimately caused by an asteroid impact leading to the eruption.
4. Triassic event (200 Myr ago) Atlantic volcanic lava flow, although an asteroid impact has not been ruled out.
5. Cretaceous event (65 Myr ago) suspected cause is an asteroid impact in the Yucatan, although volcanic activity in India has been cited frequently also.
In none of these was the primary cause listed as "global warming."
Agreed that current extinction event is partly driven by human fossil carbon exhaust leading to CO2 forcing. But I think human killing of mega/micro fauna and flora and human driven habitat destruction is at least as much to blame.
sidd
Agreed that current extinction event is partly driven by human fossil carbon exhaust leading to CO2 forcing. But I think human killing of mega/micro fauna and flora and human driven habitat destruction is at least as much to blame.
sidd
Compared to past episodes, the recent temperature change pales in comparison to large warming and/or cooling estimated to have occurred during past mass extinctions (the estimated temperature drop of the seas during the Devonian event was 15F!). Check out the animals on the endangered species list. Habitat loss is estimated to be the main threat to 85% of those species listed. Overhunting/fishing is the main threat to most of the others.
https://www.worldwildlife.org/species/directory
http://wwf.panda.org/about_our_earth/species/problems/habitat_loss_degradation/
For example, I am very concerned about ocean acidification impacting phytoplankton in the oceans and the long term impact on organic carbon deposition and the resultant levels of atmospheric CO2 and oxygen.
https://pubs.geoscienceworld.org/geology/article-abstract/24/10/867/206380/carbon-isotopes-and-the-rise-of-atmospheric-oxygen?redirectedFrom=fulltext
We know, for example, that seasonal variations in northern hemisphere terrestrial plant activity and the resultant carbon uptake causes the seasonal variation in atmospheric CO2.
http://onlinelibrary.wiley.com/doi/10.1029/JD090iD06p10529/full
Doesn't this suggest that any negative impacts on plant activity caused by increasing CO2 levels (ocean acidification) can impact O2 levels as well? More simply, reduced carbon uptake necessarily means reduced oxygen production and atmospheric oxygen levels, doesn't it?
Since I am not a scientist, I do not know if my fear is warranted.
(Would love to have my concerns set aside by contributions here from people better informed than me.)
Ouch!
I thought the Amazon was a carbon sink.
Terry
Ouch!
I thought the Amazon was a carbon sink.
Terry
Don't know where to post this, but how much CO2 did Elon Musk put into the atmosphere yesterday?
This person in the link below says it is more than an average diesel car would produce driving one million miles. (330,000kg)
Considering the annual global human emissions are about 36 billion metric tonnes, that would be about 200 metric tonnes per 5 minutes. In 5 minutes, Elon Musk put about 400 metric tonnes into the atmosphere (and his rocket that was supposed to land ... crashed into the ocean at 300mph. Twice the GLOBAL emissions for a 5 minute timeframe. Staggering to me.
Does this sound right?
https://www.quora.com/What-is-the-carbon-footprint-of-a-SpaceX-rocket
Don't know where to post this, but how much CO2 did Elon Musk put into the atmosphere yesterday?
This person in the link below says it is more than an average diesel car would produce driving one million miles. (330,000kg)
Considering the annual global human emissions are about 36 billion metric tonnes, that would be about 200 metric tonnes per 5 minutes. In 5 minutes, Elon Musk put about 400 metric tonnes into the atmosphere (and his rocket that was supposed to land ... crashed into the ocean at 300mph. Twice the GLOBAL emissions for a 5 minute timeframe. Staggering to me.
Does this sound right?
https://www.quora.com/What-is-the-carbon-footprint-of-a-SpaceX-rocket (https://www.quora.com/What-is-the-carbon-footprint-of-a-SpaceX-rocket)
This is where I think Musk's vision of establishing humanity as a multi-planet species might be counterproductive.
Until off-world colonies become fully self-sufficient, the carbon footprint of a single human being living off-world will be ENORMOUS. Food, water, medical care, manufactured goods, electronics, shelter. Almost all of this will need to be shipped from earth's surface for a long time.
I can imagine a way that the endeavor might be done in a way that won't devastate Earth, but it will take a lot more time. What I think is needed is to send a number of AI-controlled autonomous robots. They need to do mining and manufacturing to build more of themselves. Building electronic chip factories off-world will ultimately be needed. They'll need to build the habitat and start farming some foodstuffs.
When development reaches the point where humans merely need to be delivered to a home-like (mostly subterranean) environment, then we could maybe tolerate the ecologic footprint to start sending some humans. Decades, for sure. Maybe a century or two.
But regardless of how well and efficiently that might be accomplished, I'd think establishing a secure, sustainable habitat on earth would *always* be far less expensive. Even one built to withstand nuclear fallout, high CO2 levels, hydrogen sulfide in the atmosphere, zero land or sea agriculture, whatever--would be far cheaper. An inhospitable Earth environment is always going to be more amenable to human engineering than the Moon or Mars.
A strong economy and low gasoline prices can be a bad combination for planet Earth. U.S. carbon-dioxide emissions from power plants, vehicles and other sources are forecast to rise for the first time this year since 2014, according to the U.S. Energy Information Administration. The 1.8 percent uptick comes even as cleaner-burning natural gas and renewable energy replaces coal-fired power plants. “When the economy is doing well, energy demand is doing well,” Rhodium Group director John Larsen said in an interview Friday.
Over the past three years, global CO2 emissions from fossil fuels have remained relatively flat. However, early estimates from the Global Carbon Project (GCP) using preliminary data suggest that this is likely to change in 2017 with global emissions set to grow by around 2%, albeit with some uncertainties.
Coral reefs are under threat if atmospheric carbon dioxide levels continue to rise, new research has shown. When CO2 dissolves in the ocean, it raises the water's acidity level. This prevents a build up of calcium carbonate, which corals draw from seawater to build their skeleton.
The study, published today in Nature, was conducted on the Great Barrier Reef in Australia.
Coral neighbourhoods
Previous lab-based studies have focused on how particular organisms are impacted by ocean acidification.
"But when we try to scale that to understanding how individual ecosystems respond, it would be comparable to looking at a single tree and saying that's how a rainforest would respond," said Dr Rebecca Albright from the California Academy of Sciences, lead author on the study.
Dr Albright and her team worked on One Tree Island, off the coast of Queensland. The system of lagoons on the site have a very particular structure, which means that water flows in one direction across the reef flat for 60 minutes just after low tide each day. This allowed the scientists to introduce CO2-saturated water to the lagoon and observe its impact.
The study was conducted across 30 days in 2016 and showed drop of about a third in calcification - the amount of calcium carbonate sucked out of the water by coral.
This reduction doesn't lead directly to coral death in the way that bleaching does, explained Dr Albright. But it does impair the coral's growth, and ability to repair and reproduce. In the wake of bleaching events, which are caused by increased temperatures, corals will be less able to recover if the ocean's pH continues to drop. The team replicated the ocean acidity levels that are likely to be present by the middle of this century.
Pre-industrial-era oceans had a pH of 8.2. Current measurements at the site are 8.1, and the acidified water introduced for the study had a value of approximately 8.0, marking a significant impact on the ecosystem from a relatively minor change.
Not sure where to post this, but this surely has an impact on the global carbon cycle:
http://www.wri.org/blog/2018/06/2017-was-second-worst-year-record-tropical-tree-cover-loss
2017 Was the Second-Worst Year on Record for Tropical Tree Cover Loss
Last year was the second-worst on record for tropical tree cover loss, according to new data from the University of Maryland, released today on Global Forest Watch. In total, the tropics experienced 15.8 million hectares (39.0 million acres) of tree cover loss in 2017, an area the size of Bangladesh. That’s the equivalent of losing 40 football fields of trees every minute for an entire year.
Despite concerted efforts to reduce tropical deforestation, tree cover loss has been rising steadily in the tropics over the past 17 years. Natural disasters like fires and tropical storms are playing an increasing role, especially as climate change makes them more frequent and severe. But clearing of forests for agriculture and other uses continues to drive large-scale deforestation.
Let's hope those flying environmentalist globetrotters out there will compensate by planting even more trees.
Joking aside, planting trees to compensate for flying is delusional.
I'm trying to find out the extra heating that comes adding an extra tonne of CO2 (& CH4) to the atmosphere.
I think I'd like the answer in joules/sec, with perhaps the immediate change and some sense of the decay function. (CO2 - not much decay? CH4 - almost disappearing after a decade or so?)
Anyone know of an easily accessible source?
they determined the "abrupt thaw" beneath such lakes is likely to release large amounts of permafrost carbon into the atmosphere this century. The lake activity could potentially double the release from terrestrial landscapes by the 2050s.
In this study, we used output from seven CMIP5 global models, subjected to the RCP8.5 radiative forcing scenarios, to provide a comprehensive analysis of the characteristics and drivers of the intensification of the seasonal cycle of pCO 2 between present (2006–2026) and future (2080–2100) conditions. By 2080–2100 the δpCO 2 will be 1.5–3 times larger compared to 2006–2026. The projected amplification by the Earth system models and the possible causes of it are consistent with observation-based amplification for the period from 1982 to 2015 (Landschützer et al., 2018). However, the models slightly overestimate the present-day amplification, probably due to the larger pCO 2 trends in models than observations (Tjiputra et al., 2014).
The models confirm the well-established mechanisms controlling present-day δpCO 2 (Takahashi et al., 2002; Sarmiento and Gruber, 2006; Fay and McKinley, 2017). DIC s and T contributions are the main counteracting terms dominating the seasonal evolution of δpCO 2 . Furthermore, the models show that under future conditions the controlling mechanisms remain unchanged. This result confirms the findings of Landschützer et al. (2018) that identified the same regional controlling mechanism for the past 30 years. The relative role of the DIC and T terms is regionally dependent. High latitudes and upwelling regions, such as the California current system and the coast of Chile, are dominated by DIC s and the temperate low latitudes are driven by T. Only in the North Atlantic and northwestern Pacific do the models show a dominance of thermal effects over nonthermal effects, which is in disagreement with observations. This further illustrates the urgent need for models to accurately represent regional oceanographic features to accurately reproduce the δpCO2 characteristics.
In agreement with Landschützer et al. (2018), the model projections towards the end of this century also demonstrate that the global amplification of δpCO2 is due to the overall
long-term increase in anthropogenic CO2. A higher oceanic background CO2 concentration enhances the effect of T-driven solubility changes on δpCO2 and alters the seawater carbonate chemistry, also enhancing the DIC seasonality effect. The spatial differences of δpCO 2 amplification, however, are determined by the regional sensitivities and seasonality of pCO2 drivers.For example, polar regions show larger sensitivity to DIC and T and larger seasonal cycles of DIC and T. Therefore, these areas present a strong enhancement of δpCO2 in spite of smaller changes in mean pCO2.
Moreover, the pCO 2 seasonal cycle amplitude depends on the relative magnitude and phase of the contributions. The models ensemble mean reproduces the highly effective compensation of DIC s and T contributions when they are 6 months out of phase, confirming previous studies (Takahashi et al., 2002; Landschützer et al., 2018). The compensation of DIC and T prevents a larger amplification of δpCO2, even when both contributions are largely amplified.
The amplification of the TA and S contributions has a small impact on δpCO2 in most regions, except in the high latitudes at which the TA contribution complements the DIC one, enhancing the nonthermal effect in this region.
The use of Earth system models allowed us to state the importance of including future changes in driver seasonalities for future δpCO2 projections. The T seasonality is projected to increase in most of the ocean basins, thereby reinforcing the δpCO2 amplification. The δT increase is consistent with an increase in stratification that will confine the seasonal changes in net heat fluxes to a shallower mixed layer (Alexander et al., 2018). The DIC s seasonality decreases in some cold areas and its reduction prevents a larger amplification. For the sensitivities, while γ DIC increases, γ T decreases.
The latter phenomenon needs further study.
The increasing amplitude of δpCO 2 might have implications for the net air–sea flux of CO2, in particular in regions where there is an imbalance between winter and summer values (Gorgues et al., 2010). Examples of such behavior can be found in the Southern Ocean (between 50 and 60 ◦ S) (Takahashi et al., 2014a) and in the latitude band from 2–40 ◦ in both hemispheres (Landschützer et al., 2014). Moreover, seasonal events of high pCO 2 could have an impact on acidification, aragonite undersaturation events (Sasse et al., 2015), and hypercapnia conditions (McNeil and Sasse, 2016). Therefore, understanding the drivers of future δpCO2 may help to better assess the response of marine ecosystems to future changes in carbonate chemistry. Finally, our complete analytical expansion of δpCO2 in terms of its four variables provides a practical tool to accurately and quickly diagnose temperature and salinity sensitivities from observational or modeling data sets.
This result requires increasing bond-strength
diversity, consistent with the formation of organo-mineral bonds
but inconsistent with selective preservation. Radiocarbon ages
further reveal that high-energy, mineral-bound organic carbon
persists for millennia relative to low-energy, unbound organic
carbon. Our results provide globally coherent evidence for the
proposed importance of mineral protection in promoting organic
carbon preservation. We suggest that similar studies of bond-
strength diversity in ancient sediments may reveal how and why
organic carbon preservation—and thus atmospheric composition
and climate—has varied over geological time.
Significance
The great environmental disruptions of the geologic past
remain enigmatic. Each one results in a temporary change
in the oceans’ store of carbon. Although the causes remain
controversial, these changes are typically interpreted as a
proportionate response to an external input of carbon. This
paper suggests instead that the magnitude of many disrup-
tions is determined not by the strength of external stressors
but rather by the carbon cycle’s intrinsic dynamics. Theory
and observations indicate that characteristic disruptions are
excited by carbon fluxes into the oceans that exceed a thresh-
old. Similar excitations follow influxes that are either intense
and brief or weak and long-lived, as long as they exceed the
threshold. Mass extinction events are associated with influxes
well above the threshold.
The history of the Earth system is a story of change. Some changes are gradual and benign, but others, especially those associated with catastrophic mass extinction, are relatively abrupt and destructive. What sets one group apart from the other? Here, I hypothesize that perturbations of Earth’s carbon cycle lead to mass extinction if they exceed either a critical rate at long time scales or a critical size at short time scales. By analyzing 31 carbon isotopic events during the past 542 million years, I identify the critical rate with a limit imposed by mass conservation. Identification of the crossover time scale separating fast from slow events then yields the critical size. The modern critical size for the marine carbon cycle is roughly similar to the mass of carbon that human activities will likely have added to the oceans by the year 2100.
... "We see the amount of carbon drops drastically, by orders of magnitude, during this PETM event," ... So at least in Wyoming, my data suggests soils acted as a source, not a sink, for carbon dioxide
Thanks Vox!
This looks like another chunk out of the budget?
And this makes me wonder about how climate models actually interact with soils...
The results show trees and plants could remove six years of current emissions by 2100, but only if no further deforestation occurs.
The study, led by Stanford University and the Autonomous University of Barcelona, and including Imperial College London researchers, is published in Nature Climate Change.
As plants grow they take in carbon dioxide (CO2) from the air. As CO2 concentrations in the air rise due to human-caused emissions, researchers have suggested that plants will be able to grow larger, and therefore take in more CO2.
However, plant growth is not only due to CO2 concentrations, but relies on the availability of nutrients in the soil, particularly nitrogen and phosphorus. If the plants can't get enough nutrients, they will not grow more despite higher CO2 concentrations.
Hundreds of experiments over the past few decades have tried to determine how much extra CO2 plants can take in before the availability of nutrients becomes limiting, but many have come up with different answers.
Now, a group of 32 scientists from 13 countries have analysed all the previous experiments to come up with a global estimate of plants' ability to take in CO2.
Their results show that globally plants can increase their biomass (organic material) by 12 percent when exposed to concentrations of CO2 predicted for the year 2100.
This extra growth would draw enough CO2 from the atmosphere to cancel out six years of current human-induced emissions.
However, the result is based on plant and forest cover remaining at current levels -- so no further deforestation occurs.
Lead author Dr César Terrer, now at Stanford University's School of Earth, Energy & Environmental Sciences, initiated the project while at Imperial College London. He said: "Keeping fossil fuels in the ground is the best way to limit further warming. But stopping deforestation and preserving forests so they can grow more is our next-best solution."
Several individual experiments, such as fumigating forests with elevated levels of carbon dioxide and growing plants in gas-filled chambers, have provided critical data but no definitive answer globally.
To more accurately predict the capacity of trees and plants to sequester CO2 in the future, the researchers synthesized data from all elevated carbon dioxide experiments conducted so far, in grassland, shrubland, cropland and forest systems.
Using statistical methods, machine-learning, models and satellite data, they quantified how much soil nutrients and climate factors limit the ability of plants and trees to absorb extra CO2.
They found that tropical forests had the greatest capacity for growth and increased CO2 uptake, such as those in the Amazon, Congo and Indonesia.
Dr Terrer said: "We have already witnessed indiscriminate logging in pristine tropical forests, which are the largest reservoirs of biomass in the planet. We stand to lose a tremendously important tool to limit global warming."
The study also shows how plants' and trees' ability to absorb extra CO2 relies on their association with different fungi in their roots, which help them get extra soil nutrients.
The results of the study will be valuable to scientists building models of future climate change and the impact of reforestation or deforestation.
Seems to show that the increased uptake of CO2 by plant matter at increased levels of atmospheric CO2 will continue, even in the face of nutrient limits proposed by other research.
But is there enough water vapour?
https://www.carbonbrief.org/rising-water-stress-could-counteract-global-green-study-says
<snip>
Article in Nature Climate Change is under a paywall, maybe someone would have access?
<snip>
Article in Nature Climate Change is under a paywall, maybe someone would have access?
Is this the one?
https://sci-hub.tw/https://doi.org/10.1038/s41558-019-0557-y
Scientists have known for quite some time that northern forests sequester a lot of carbon—they pull in carbon dioxide after all, and "breath" out oxygen. But what the trees actually do with the carbon has been a matter of debate—most have suggested that it's likely carried to needles and leaves then eventually drops to the forest floor where over time decomposition causes it to leech into the soil. If that were the case, this new team of researchers reasoned, then the newest carbon deposits should appear closest to the surface of the forest floor. But this is not what they found—instead they discovered that newer deposits were more likely to be found at deeper levels in the soil. This was because, they learned, the trees were carrying much of the carbon they pulled in down to their roots (via sugars) where it was being sequestered by a type of fungi (ectomycorrhizal, aka mycorrhizal fungi) that eats the sugars and expels the residue into the soil.
In their study they found that 47 percent of soil carbon found on large island samples came about due to fungi, as did a whopping 70 percent of carbon in small island soil samples. Thus far, the team is only able to guess why there are such differences in the soils, but theorize it's likely due to differences in decomposition rates.
This seems like quite a break-through in understanding.
Study finds fungi, not plant matter, responsible for most carbon sequestration in northern forests
https://phys.org/news/2013-03-fungi-responsible-carbon-sequestration-northern.html?fbclid=IwAR3PcB6XPEY5lAmM2Pj_T829JD954qG61OWMfdyWLE_1K06tSzGkA09X0skQuoteScientists have known for quite some time that northern forests sequester a lot of carbon—they pull in carbon dioxide after all, and "breath" out oxygen. But what the trees actually do with the carbon has been a matter of debate—most have suggested that it's likely carried to needles and leaves then eventually drops to the forest floor where over time decomposition causes it to leech into the soil. If that were the case, this new team of researchers reasoned, then the newest carbon deposits should appear closest to the surface of the forest floor. But this is not what they found—instead they discovered that newer deposits were more likely to be found at deeper levels in the soil. This was because, they learned, the trees were carrying much of the carbon they pulled in down to their roots (via sugars) where it was being sequestered by a type of fungi (ectomycorrhizal, aka mycorrhizal fungi) that eats the sugars and expels the residue into the soil.
In their study they found that 47 percent of soil carbon found on large island samples came about due to fungi, as did a whopping 70 percent of carbon in small island soil samples. Thus far, the team is only able to guess why there are such differences in the soils, but theorize it's likely due to differences in decomposition rates.
I wonder if the sequestering fungi associated with the tree roots are yet being directly fed by falling needles etc? Or, are they saying something else entirely? Because I always assumed fungi to be involved in the breakdown of dead plant material - just never understood it to be transmitted so deeply in the soil....
Carbon emitted from thawing permafrost has not been included in the majority of models used to predict future climates
This seems like quite a break-through in understanding.
Study finds fungi, not plant matter, responsible for most carbon sequestration in northern forests
...
In their study they found that 47 percent of soil carbon found on large island samples came about due to fungi, as did a whopping 70 percent of carbon in small island soil samples. Thus far, the team is only able to guess why there are such differences in the soils, but theorize it's likely due to differences in decomposition rates.
Mid-Pleistocene transition in glacial cycles explained by declining CO2 and regolith removalhttps://advances.sciencemag.org/content/5/4/eaav7337 (https://advances.sciencemag.org/content/5/4/eaav7337)
M. Willeit,*, A. Ganopolski, R. Calov and V. Brovkin
Abstract
Variations in Earth’s orbit pace the glacial-interglacial cycles of the Quaternary, but the mechanisms that transform regional and seasonal variations in solar insolation into glacial-interglacial cycles are still elusive. Here, we present transient simulations of coevolution of climate, ice sheets, and carbon cycle over the past 3 million years. We show that a gradual lowering of atmospheric CO2 and regolith removal are essential to reproduce the evolution of climate variability over the Quaternary. The long-term CO2 decrease leads to the initiation of Northern Hemisphere glaciation and an increase in the amplitude of glacial-interglacial variations, while the combined effect of CO2 decline and regolith removal controls the timing of the transition from a 41,000- to 100,000-year world. Our results suggest that the current CO2 concentration is unprecedented over the past 3 million years and that global temperature never exceeded the preindustrial value by more than 2°C during the Quaternary.