When C.S. Callendar became interested in CO2 and the greenhouse effect ( around 1938) , he was arguing that increasing CO2 might prevent some future glaciation - what is repeated sometimes, without much dicussion.
To point out essential patterns of the climate change induced by the changing solar radiation ( as Milankovich and others discovered ) a simplified approach to the natural clima variation may be considered:
Ice Ages (in distances of 100 000y) - tropical forests wet, good CO2 capture.
Interglacial Times ( only around 15% between Ice Ages, CO2 level growing) -
tropics are less wet, emitting CO2 in certain periods of decay,
northerns woods growing in areas of former ice fields, capturing some CO2.
The drying of the Sahara and other areas in the present warm phase emitted CO2, atmospheric CO2 level increased and is partly feeding the slowly growing forests in the northern hemisphere.
The scenario during the warm phase has a periodic depression in winter times, when the photosyntesis in the northern hemisphere is retarded.
When the solar radiation is diminished ( in the Milankovich cycle with its adjustments ), ice is growing again from the remaining ice fields and the earth becomes more wet again.
Burning fossil material is often noxious and may enhance a CO2 level, which is already high by the natural processes, but in times of lowest CO2 during the peaks of ice ages it would be good for more photosynthesis, to get easier over the minimum.
Fossil burning during phases of high temperature and high CO2 level is obviously the contrary and topic of the climate debate.
An effect on future ice ages is hard to detect.
Kenneth My simple model is only related to the periodic ice ages of the Pleistocene. It considers very few parameters.
Particularly it cannot be applied or extended to the much earlier Eem period with other atmospheric conditions and plants. Appearently it is more difficult to understand.
The extent of the present consumption worldwide endangers nature and the natural basis of humanity.
In restriction to regarding fossil fuels it can be stated, that the emission of CO2 would do much less harm during periods, where C02 is naturally low as during the peaks of ice ages ( the next one being possible within 100 000 years, a period which is also considered for deposit of nuclear material in Finland now ) .
Therefore it makes sense to delay coal mining and exploitation of other fossil fuels.
Why not study, how life is possible in countries of low CO2 emission, imstead of adapting to the wasteful lifestyle of many industrial countries ?
I find in the list of low CO2 emission per capita ( in tonnes CO2 per year ) presently :
Tunesia (2,5) Brazil (2,15) India (1,7) Pakistan (1) Bhutan (0,7) ,
less than one quater of the emission in Germany.
Of course, each country has its specific problems too, also environmentally - but the low emission rates are impressive.
Apart from the number also the emission per capita counts and is crucial: If all people had emissions as low as those in Tunesia or India, there would not be a climate problem and no conferences as now in Paris.
The pleistocene with its regular ice ages exists only within certain parameters. Tectonic motion of the continents and other evolutions on earth and of the sun will change it. One of the limits is the decreasing CO2 level on earth within 100 million years due to interaction of the athmosphere with the earth´s surface and the decreasing activity of the volcans, as first detected by J.Lovelock and M.Whitfield 1982: CO2 is continuously absorbed at the earth surface and will drop to 250 ppm in the athmosphere.
At this level, to be expected in about 100 million years, most plants cannot survive, their C3 photosynthesis does not work anymore, but those of the C4 type ( as millet and maize/corn, but not wheat ) can resist and gradually occupy the place of the decaying vegetation prevailing hitherto.
Furthermore, it cannot be excluded that future high CO2 levels due to combustion of fossil fuels exceed the stable range of the present pleistocene parameters.
Keneth I cannot see, what should be wrong with my last sentence.
There are many quasi-equilibrium conditions possible, if a nearly indefinit number of forces and materia interact.
I cannot realise that anybody can calculate, how the earth climate evolves, if quasi-equilibrium conditions are left. Therefore I think, nothing can be excluded.
Isn´t the pleistocene " The Best of All Possible Worlds" in the sense of geophysics - small oscillations around moderate temperatures and no rapid changes in the atmospheric composition. It took a while to settle down the solar radiation by the vegetation reducing CO2 and evaporating; best management of climate. We should not endanger it.
The idea in the climate debate was, that the industrial countries begin to lower the per capita exhaust of CO2, but there were too many priviliges exempted up to now.
I find it interesting to explore personally, e.g.,how to reduce private traffic, eating less meat and insulating buildings.
Its not only the social responsability, but the beauty of nature too which I like to share with everybody who has a feeling of this kind.
People should learn ( a majority being often functional analphabets), infrastructure has to be improved, in Paris the Global Solar Coucil was founded for constructing solar panels worldwide.
Every step only a small percentage - as on the other side the way to hell too.
In China renewable energy use is growing faster now than fossil energy.
Renewable energy programs are working in India and Africa.
To accumulate materia ( the way in economy hitherto ) is a bit outdated, if people suffer too much and prefer more harmony. Thinking more and constructing better than coal-fired powerplants.
Lovers of nature could consider, that it does not make sense to heat and dry further the earth ( already too much in India and Africa ), the present century is the wrong one to waste fossil fuels. Give you a time to relax and then postpone coal mining to later centuries and start renewable energy, reforestation and better managing of agricultural areas now. Eat potatoes, soy beans, cereals yourself, many vegetarians do it successfully ( also for their health ) and do not feed a large part of the harvest to animals, then there is enough to eat in the future !
Hello Freek, you have insight into Mars Craters and are interested in landing places .
The scientists working now for the Paris conference and the coming conclusion are working for the people left down on earth.
The ice age cycles of atmospheric CO2 where driven mainly by the ocean -- not forests on land.
Article The polar ocean and glacial cycles in atmospheric CO
Chapter The Biological Pump in the Past
Hallo Mathis, thanks for your references: The CO2 exchange processes in the southern hemisphere are important and are different in interglacial times.
Is it possible that the biological pump ( the term you use in your publications ) is nearly periodic, i.e., that about the same quantity of CO2 is evaporating to the atmosphere as is later dumped - from/to the (southern) ocean ?
Is the CO2 released to the atmosphere during warm phases by decaying vegetation ( for example between the Mediterranian and the Sahel ) comparabel or not to the amount which is exchanged at the ocean´s surface ?
Herbert, yes, the cycles in ocean biogeochemistry were strongly coupled to the natural glacial/interglacial climate cycles (see Figure 8 in the Treatise on Geochemistry review I sent). During ice ages a "more efficient biological pump" was sequestering more carbon from the atmosphere into the deep ocean, and this carbon was released back to the atmosphere during glacial terminations. As for your second question, no, there is good evidence from marine CaCO3 burial changes that the vast majority of glacial/interglacial atmospheric CO2 change was caused by the ocean. That is, the possible contribution from carbon reservoirs on land must have been small in comparison.
Kenneth, no, the ocean changes I refer to have basically nothing to do with ENSO. Also, you are mistaken to say that organic carbon needs to be buried in order to affect CO2. The biological pump maintains a stock of "sequestered carbon" in the global ocean deep waters, and the size of that stock changes along with the efficiency of the biological pump -- thereby changing atmospheric CO2 without any burial.
Kenneth, my points were: (1) the biological pump can change atmospheric CO2 even if there are no changes in organic carbon burial (irrespective of timescale), and (2) ENSO has nothing to do with the glacial/interglacial cycles of climate or CO2. The argument about CaCO3 involves observed, transient CaCO3 preservation events after the ocean released the CO2 back into the atmosphere during glacial terminations -- this has nothing to do with the Dover cliffs. Why are you responding to Herbert's question when you clearly know little about the causes and mechanisms of glacial/interglacial CO2 change? If you are interested in the topic I recommend that you actually read one of the review articles that I posted to let Herbert know that his hypothesis is fatally flawed.
The long-term burial happened b e f o r e the present periodic ice-ages began.
Is there a specific reason, why the biological pump works only after burial ?
The biological pump consists of three mecanism working subsequently together. Which one supposes the burial ? Can it be explained, why the periods of former ice ages were longer ?
Mathis, you posted your last answer 6 minutes before mine and I could read it only later.
Do you find something wrong in my original Question - except that I dared to mention that the emitted CO2 of the vegetation is p a r t l y feeding . . forests . ??
I confess, that I should not have said it this way - because it might suggest this it is the only or the main reason for rising CO2 in the athmosphere.
I wasn´t really sure about it, so I am glad that you guided me to the concept of the biological pump.
"As for the glacial stuff... the late Eocene, as noted here earlier, tells us that CO2 can be high and ice sheets can form and grow." Again, we have to ask ourselves what the real agenda of the IPCC and their scientists is. Carbon trade profits could amount to a trillion dollars over time. Could this perhaps have been the reason to fabricate AGW? It would be the greatest theft in the history of mankind.
Herbert, in my reading of your initial post I find three key questions: (1) terrestrial vegetation drives natural CO2 changes over glacial/interglacial cycles? (2) higher atmospheric CO2 concentration fertilizes some forest systems ? and (3) anthropogenic CO2 emissions offset CO2 reductions of the next ice age?
These are my response:
(1) The ocean's biological pump was the main driver of glacial/interglacial CO2 change. These CO2 changes are natural and occur over thousands of years.
(2) You are correct, higher CO2 fertilizes at least some plants and thereby helps store carbon away from the atmosphere into the terrestrial carbon reservoir. This is an important area of ongoing research.
(3) Our industrial activities have increased atmospheric CO2 by 120ppm and rising in less than 200 years. Glacial/Interglacial CO2 change (~100ppm) took thousands of years to manifest. Thus, we are doing far more than to "offset" natural CO2 change -- we are fundamentally changing the planetary acid/base chemistry and climate system.
You are raising important questions that are at the heart of ongoing research. I highly recommend that you read up on these topics in peer-reviewed scientific articles and not simply trust what people say in online forums. Some commenters may have an agenda to obfuscate scientific discourse and general consensus.
Mathis, the biological pump is working mainly around the Antarctis (?). Then it would be coupled less closely to the driving forces in the northern hemisphere, which are the changing currents of the oceans triggered by the solar periods of around 100k years.
How do you relate the biological pump hypothesis to the present absorption of fossile CO2 - about half by the forests and half by the oceans - where the increasing acidity may endanger and reduce the oceanic capacity of absorption ?
Since a part of the atmospheric CO2 is absorbed on land, it has to be included in the biological pump hypothesis. Land absorbed CO2 flows with water and sediments back to the oceans later.
Dear Herbert, why don't you just read the papers I attached in the thread above? You can not just include land carbon reservoir changes into the ocean's biological pump.
These are the first 1.5 paragraphs of "The Biological Pump in the Past":
Almost all organisms on Earth either harvest energy and produce organic matter through photosynthesis, or feed on organic matter that was ultimately produced by these ‘photoautotrophs.’ In addition to light as their source of energy, photoautotrophs require nutrients and inorganic carbon, which they extract from the environment. On land, newly produced biomass is rapidly recycled by plant respiration or heterotrophy, but a small frac tion survives for a longer time before decomposition, either as long lived tissue (e.g., wood), soil organic matter, peat, or organic matter buried in sediments. This leads to the accumula tion of terrestrial organic carbon, at the expense of the environ mental inorganic carbon reservoir, including atmospheric carbon dioxide (CO2). An increase in the quantity of terrestrial organic carbon driven by a temporary excess in organic carbon produc tion relative to its oxidation thus lowers atmospheric CO2.
In the ocean, there are no aggregations of biomass compa rable to the forests on land. Yet biological productivity in the ocean plays a central role in the sequestration of carbon away from the atmosphere, overshadowing the effects of terrestrial biospheric carbon storage on timescales longer than a few centuries. In an effort to communicate the ocean’s role in the regulation of atmospheric CO2, marine scientists frequently refer to the ocean’s biologically driven sequestration of carbon as the ‘biological pump.’
I am sorry that I came back to the CO2 sequestration on land, which is not of the time scale of interglacials. - Fossil fuel CO2 sequestration is considered in engineering studies of CCS. Furthermore, reducing atmospheric CO2 might be possible in principle by burning biomass and pumping the resulting CO2 into empty oil layers, if deep and safe enough.
The next ice age can be partly suppressed by the increased atmospheric CO2 level according to D. Archer , 2005 .
Nevertheless, CCS technology was investigated in a couple of countries, it could neutralize emissions in a few decades, if further developed.
Other means working insufficiently at present are CO2 taxes and/or emission trade.
In 2013 the ecuadorian Yasuni-ITT project was abondoned, where 410 million to CO2 should not be emitted from an explored oil field, recompensating a price per ton similar to that in the EU emission trade.
To withdraw support for fossil fuel energy could provide for half the wanted reduction until 2050, according to the London School of Economics.
Thanks for all contributions; there are many sights and questions.
Although most interaction of the released fossil CO2 with the earth´s surface happens in few hundred years, warming of the earth can last for thousands of years.
The models for these processes and consequences are reviewed by D.Archer and coauthors Annu.Rev. Earth Pl. Sci. 37, 117-36 2009 doi: 10.1146/annurev.earth 031208.100206
The onset of the next ice age can be prevented within the next 500 ky is the result of D. Archer, A.Ganopolski G3 Res.Lett. Vol 6,5 5May 2005 doi:10.1029/2004GC000891
Archer and Ganoposki studied, how different CO2 loads could reduce the temperature fluctuations of coming ice ages neglecting natural CO2 variations and other data - nevertheless an interesting first approach.
Assuming that the absorption of the excess CO2 is similar as that of the natural one during phases of beginning cooling the maximum duration 500 ky would be reduced.
The peculiar thing about plants and trees is, that the vast majority of "them" have evolved and thrive under conditions where there was far more CO2 in the atmosphere, around 450 ppm. They are practically starving at the current low levels.
http://www.plantsneedco2.org/default.aspx?menuitemid=338
There are some publications pretending that at the beginning of the industrial revolution in the 18.century the CO2 level was slightly above the limit, so that the next glacial intercept is missed and delayed about 50 000 years.
What is changed further due to fossil emissions ? This is considered too by A. Ganopolski, R. Winklmann and H.J. Schellnhuber in a Nature/Letter (Earth&Env. Sec.) 529/200-203, Jan.2016 CRITICAL INSOLATION - CO2 RELATION F. . . . . GLACIAL INTERCEPTION DOI:10.1038/nature 16494
explaining the last eight ace ages and predicting a further delay of 100 000 years for glacial interception due to fossil emissions.
One of the consequences of our present fossil fuel burning is the rise of the sea level in the next thousand years. This was investigated considering the past and coming ten thousand years. The oceans do not forget and will rise and inundate costal areas as shown, if not prevented mechanically ( or pumping water far into Antarctica as discussed in another paper with coauthor Anders Levermann ). Longreaching consequences depend on the total fossil emissions.
P.M. Clark et al. Consequences of 21st Century policy for Millenial Climate and Sea-level-Change
Nature Climate Change 6 (2016) doi: 10.1038/nclimate2923
There is a difference predicting decades and a decade of thousand years. Furthermore, the calculation covers the data of the past.
The main contribution comes from Antarctica and its particular conditions of the connection between ice and rock at the ground, of the water circulation and so on.
I agree that employment should not depend on political opportunity, which means up to now predominantly dependancy on an economy driven by dirty energy.
There is obviously no period within the last and coming 100 000 years, where the emission of fossil fuels with the present extent is not harmful to the stability of climate.
Consider that many mammals of more than 45 kg died out in the Quarternary, the Neanderthal people too ( at a period of climatic stress ), leaving only a few percent to the genom of the present humanity. We are survivors, and were under the control of droughts, inundations ( which interrupted the first kindoms of Egypt, e.g. ), disorders and wars.
Today the supply of cereals is crucial for an increased world population. However, soil and the total earth`s surface are degraded with the help and by the emanations of fossil fuels.
Whereas the Roman empire suffered at its end by lack of cereal supply from northafrican colonies becoming more independent, today more types of dangers are in sight. Apart from inadequate treatment of the earth the limited sources of fossils fuels do not allow to continue the present growing and devastating economy.
My foundation adresses very few students to develop personal thinking.
There is no overall solution fitting everybody. There were and are always people working for their power and often with little feeling for the damage which may result.
I do not see, that humanity has a single problem, the tasks are interrelated. For example, education is recommended to reduce too many human offsprings and to prepare and provide more for a peaceful living-together.
Instead of investing more in economy ( see divest movement, for example ) some universities and others find better goals.
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