Guest essay by Clive Best
Summary
The currently held belief that we must decarbonise the world’s economy in order to to stop climate change is a dangerous illusion. It is a ‘hiding to nothing’. I have come to the conclusion that if emissions were held constant for 30 years then the airborne fraction of CO2 emissions would reduce to zero. In other words if the world can hold emissions constant at say 30GT CO2/y then sinks will increase to balance all annual emissions. Thereafter CO2 levels would remain at below 440ppm indefinitely, so long as emissions remain constant.
Introduction
I will argue below that in order to stop global warming all we really have to do is simply stabilise CO2 emissions, not reduce them to zero! This alone will stabilise CO2 levels within less than 30 years. The origin of the ‘myth’ as promoted by nearly all IPCC climate scientists is that we have to stop burning all fossil fuels i.e. we must ‘keep it in the ground’. This is a fallacy and I will try to explain why in this post.
The origin of this belief that we must stop burning any fossil fuels by ~2050 can be traced back to Figure 10 which appeared in the AR5 ‘Summary for Policy Makers’. Here it is again.
Figure 10 from SPM AR5
Figure 10 was intended to send a simple message to the world’s political leaders. Namely that there is a finite total amount of fossil fuel that mankind can ever safely burn, and that we have already burned half of it. Therefore unless all major industrialised countries stop burning fossil fuels altogether by 2050, the world will warm far above 2C (the red curve) causing a global disaster. This message worked, but I find that there is so much wrong with the hidden assumptions and even subterfuge used to produce Figure 10 that I wrote a post about it at the time.
The principal hidden assumptions, as I see it, in Fig 10. are as follows:
1. Carbon sinks are saturating (they are not)
2. ECS (Equilibrium Climate Sensitivity) is 3.5C (Very uncertain – and could even be as low as 1.5C)
3. The subtle replacement of logarithmic forcing of CO2 with a linear forcing.
4. The assumption that past emissions stay in the atmosphere essentially forever.
As a direct consequence of IPCC successful lobbying based essentially around Figure 10, the Paris treaty now proudly “sets the world on an irreversible trajectory on which all investment, all regulation and all industrial strategy must start to align with a zero carbon global economy“. Does anyone really believe that this is even feasible, let alone realistic? It simply is not going to happen because well before then, their citizens will revolt and kick them out. The best we can hope for in the short term is a stabilisation of global CO2 emissions. The minimum condition needed is that annual growth in emissions needs to be brought to zero.
Carbon Cycle
To understand the carbon cycle means understanding the difference between CO2 decay time and CO2 residence time. The decay time for an individual CO2 molecule emitted by man is only about 5-10 years (based on C14 measurements in both bomb tests and those produced by cosmic rays). Every CO2 molecule in the atmosphere is rather quickly absorbed either by photosynthesis or by the ocean. However on average most of them are simply replaced by another CO2 molecule entering the atmosphere through evaporation from the ocean surface or by biological respiration. The residence time however, is the e-folding time needed for a sudden net increase in CO2 to decay back to normal as the carbon cycle reacts. At equilibrium the total CO2 content of the atmosphere remains constant over centennial time scales. Currently though, as a result of our emissions, slightly more net CO2 molecules are being absorbed than are being returned to the atmosphere each year. As a consequence the atmosphere is not quite in equilibrium with the rest of ‘natural’ life and the oceans. We have given the carbon cycle a kick, and as a result it is reacting to return back into balance. The problem is that we have continued to kick a little harder each year so that balance is never reached.
If you sum up all the sources and sinks since 1960 then you find a remarkable fact, which was unexpected by climate scientists. About half of man-made emissions are being absorbed each year. This means that just one half of the net CO2 emitted by humans remains in the atmosphere each year. This is called the airborne fraction. The strange thing is that this airborne fraction hasn’t changed at all in 60 years, despite exponentially increasing human emissions.
AR4 plot: The fraction of Anthropogenic CO2 retained in the atmosphere (b) is unchanged in 50 years, despite increasing emissions (a). Note how the annual change stalled after the 70s oil crisis
Plot of Carbon content of air versus Cumulative Carbon emissions produced by Nick Stokes.
This means that today we are emitting about twice as much carbon dioxide as we did 30 years ago, yet still only half of it survives a full year. Or putting that another way, the equivalent of 100% of 1990 emissions are now absorbed each year. This ratio of 50% airborne fraction has been true for over 100 years while emissions have been forever increasing.
Comparison of Carbon emissions and that retained in the atmosphere. Increases in Emissions consistently remain about twice the levels of increases in CO2. Flat periods occur when growth stalls.
Natural carbon sinks are increasing dynamically to offset our emissions. The problem is that they don’t have enough time to catch up with the ever increasing rate of emission. The best they can do in a single year is offset half of them. Why is that the case and what does it really mean?
There is a ‘concentration effect’ acting on ocean sinks due to the increasing partial pressure of CO2 in the atmosphere. Similarly land biota (plants and soil) react to increased partial pressure by absorbing more CO2. While we are still increasing emissions then CO2 levels in the atmosphere will always continue to rise. If instead we can stabilise emissions at some fixed number of Gtons/year then CO2 levels would also stabilise, albeit at a slightly higher level than now and in the future. This is because the sinks will finally be able to catch up to balance our CO2 source. The atmospheric faction will decay to zero.
Dissolution/Absorption of CO2 at Ocean surfaces.
In stability there is a balance of CO2 Partial Pressures between the surface of the ocean and the atmosphere. At any given temperature the exchange of carbon dioxide molecules between the atmosphere and the ocean surface always reaches an equilibrium. This equilibrium is controlled by the partial pressure of CO2 in the atmosphere equalising to the partial pressure of CO2 in the surface of the ocean. Then the number of carbon dioxide molecules that escape from the sea surface is balanced by the number that enter the sea from the atmosphere.
If the temperature of the ocean rises then the kinetic energy of the carbon dioxide molecules in the seawater increases and more carbon dioxide molecules will leave the ocean than would enter the ocean. This continues until the partial pressure of carbon dioxide in the atmosphere increases to balance the new pressure at the sea surface.
If instead the ocean were to cool then the reverse of the above would happen, and CO2 levels would fall. Consequently carbon dioxide is more soluble in cold water than in warm water. This is Henry’s law. One consequence of this effect is that the oceans “inhale” carbon dioxide from the atmosphere into cold sea surfaces at high latitudes and “exhale” it from warm sea surfaces at low latitudes.
Increasing the carbon dioxide concentration of the atmosphere therefore causes the oceans to take up (inhale) more carbon dioxide. Because the oceans surface layer mixes slowly with the deep ocean (hundreds of years) the increased carbon dioxide content of the surface ocean will be mixed very slowly into much larger carbon reservoir of the deep ocean. The rate of our adding carbon dioxide to the atmosphere has been too fast for the deep ocean yet to be a significant reservoir. So as the carbon dioxide content of the atmosphere rises, so too does the concentration in the ocean surface, causing short term acidification of surface waters. If atmospheric carbon dioxide remains constant then a ph balance throughout the ocean volume can be reached.
I argue that by simply stabilising emissions, we can halt global warming because CO2 levels will stabilise as the sinks will then be able reach equilibrium with emissions. Clearly the lower total ‘stable’ emissions become then the cooler the planet will be, but even if we only managed to stabilise emissions at current values, then the net warming will still be <2C and CO2 levels will soon stop rising and stabilise at <440 ppm.
Atmospheric CO2 levels must always reach an equilibrium as the natural carbon sinks catch up to balance emissions. For the last 40 years about half of man-made emissions have been absorbed mainly into the oceans, but also into soils and biota. The reason why CO2 levels have been continuously increasing since 1970 is that we have been increasingemissions each year, so the sinks never get a chance to catch up. Sinks will rather quickly balance emissions and CO2 levels will stop rising once emissions stop increasing. This fact is obvious because run-away CO2 levels have never happened before in the earth’s long history. Such a balancing mechanism has always stabilised atmospheric CO2 over billions of years during intense periods of extreme volcanic activity, ocean spreading and periodic tectonic mountain building. Fossil fuels in this context are an insignificant fraction when compared to the buried carbon contained in sedimentary rocks.
Simple Model
CO2 levels rise when the rate of change of the sources – S exceeds the rate of change of sinks – K. Without human emissions then S = K, averaged over one year. However with ever increasing human emissions the situation becomes dynamic
If C is the yearly value of CO2, S the net sources of CO2 and K the net sinks, then at time t.
However it has been measured for at least the last 60 years that
If 
then 
Now let’s assume that the world manages to stabilise annual emissions at current rates of 34 Gtons CO2/year indefinitely. CO2 sinks currently absorb roughly half of that figure – 17 Gtons and have been increasing proportional to the increase in partial pressure of CO2 in the atmosphere – currently that of 400ppm. Stabilising emissions now results in a decreasing fractional uptake by carbon sinks as the partial pressure imbalance between the surface and atmosphere begins to fall. The simplest assumption is that the sink increase depends only on the partial pressure difference for a given year. Therefore if this pressure difference is reduced by half in one year then the next year it will be reduced by one quarter, then one eighth and so on. The same argument applies for the case that it takes longer to reduce pressure difference by a half.
Year 1: 50% Year 2: 25% Year 3: 12.5% Year 4: 6.25% etc. which is simply equal to the infinite sum
So in this simplest of models, CO2 levels in the atmosphere will taper off after just ~10 years to reach a new long term value equivalent to adding an additional one year of emissions 34 Gtons of CO2 to the atmosphere. The atmosphere currently contains 3.13 x 10^12 tons of CO2 so the net increase at equilibrium would in this simple model be just 1%. Therefore for the years following 2016 the resultant CO2 curve would look like the red curve below. If instead it takes say 4 years for the sinks to increase by 
then we get the blue curve. In this case it would take 30 years for CO2 levels to to stabilise and the increase would be 5 times larger.
CO2 stabilisation curves for different time constants. The red curve assumes sinks match half the imbalance in 1 year while the blue matches it in 4 years.
Currently there is also a good chance that the world will achieve a fixed level of annual emissions, but there is no chance that it will meet an impossible target of zero emissions this century. This does mean that CO2 levels will remain at ~410 ppm indefinitely, which is far higher than a planet without human beings, but it buys us time to replace fossil fuels with say new nuclear energy. If I am right then CO2 levels will begin to level off within the next 10-20 years. This would also save trillions of dollars by trying too soon now to replace all fossil fuels, and then probably failing.
Reducing emissions in the future will slowly cause such ‘stable’ CO2 levels to fall. In the long term we will have to develop non-carbon energy sources anyway, most likely nuclear, since fossil fuels must run short. However using remaining fossil fuels to control CO2 levels may one day have another advantage. It could mean that we can eventually use ‘enhanced global warming’ as a thermostat, thereby avoiding another devastating ice age otherwise due to begin within the next 5000 years.
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” The simplest assumption is that the sink increase depends only on the partial pressure difference for a given year. “
That’s where I think it goes wrong. In terms of diffusion, that is characteristic of a layer of finite thickness with an infinite zero-impedance sink behind. Then you get exponential behaviour. Flux proportional to partial pressure difference.
But when diffusing into an infinite but resistive sink, you get behaviour associated with gaussians, error functions etc. And that is where the rising with sqrt(t) comes from.
Imagine a very well insulated house that is cooling. Heat escapes through the walls in that exponential way, with half-life etc. Because the windy environment is an infinite low impedance sink. Heat can also flow into the ground, also infinite. But the ground warms up, and takes more heat with increasing reluctance. For a maintained temperature, the flux drops as 1/sqrt(t).
The problem with CO2 is that we don’t have a wind to take it away where it won’t bother us. We only have small biomass sinks, and the diffusive sea.
That’s where I think it goes wrong
Well it is not really very wrong though is it? You are just saying that there is impedance damping to delay or offset rebalancing. Well maybe you’re right and maybe not.
“Well it is not really very wrong though is it?”
Yes, it is. You are basically assuming that each new bit of CO2 released can get to a sink in the same way as its predecessors, independently. That’s where the half-life stuff etc comes from.
But it isn’t like that. New CO2 has to make its way (in the sea) through previous CO2. That is the big diffrence between maintaining a constant flux indefinitely with no partial pressure rise, and an inevitable and continuing rise (sqrt(t) behaviour). The sea doesn’t saturate. But resistance to flux increases.
but THC .
( nothing to do with pot ).
Nick,
As said before, and affirmed by Greg, the THC (and other ocean currents) are simply renewed at high rate, where the upwelling is not affected by humans (it will over ~1000 years) and thus will absorb the same amount of CO2 when sinking near the poles (assuming the same low temperature there)…
Btw, wind speed is another big factor that influences the speed of exchange. For the whole mixed layer that makes that the equilibrium with the atmosphere has an e-fold exchange rate of less than a year, but the problem there is that the ocean buffer gets saturated at about 10% of the change in the atmosphere (the “Revelle factor”). That doesn’t play a role for the deep oceans…
The wind is the THC. It constantly removes the cold surface water so resistance does not increase.
It is precisely that “long tail” dynamic which, in the near term, leads to an integrating response with temperature. It’s right in front of your eyes:
http://woodfortrees.org/plot/esrl-co2/derivative/mean:24/plot/hadcrut4sh/offset:0.45/scale:0.22/from:1958
Or we could maybe repair the 42% destruction of our life support system and never have to worry about CO2 in the atmosphere again?
“so long as emissions remain constant.”
ROFLMAO
NO. CO2 emissions will continue to climb and climb for MANY years.
And once this ant-science, socialist scam, anti-CO2 agenda is consigned to the SCRAP HEAP where it belongs, the world will rejoice at the massive increase in food and prosperity that fossil fuels have given.
Burning gas is decarbonisation since energy is also the product of burning hydrogen.
we know from the experience of the US with shale, that the switch from coal powered generation to gas powered significantly reduces CO2 emissions.
By contrast Germany that has gone down the renewable route, has seen no reduction in CO2 emissions these past 15 years.
Gas works, renewables do not.
This was exactly my thought also. But it could be even better.
a lignite power plant has about 30% efficiency and produces 1200 gr CO2/per kwh
A standard gas turbine has an efficiency of about 40-45% and emits about 600 gr CO2/kwh
A state-of-the-art Combined Cycle Gas power plant has an efficiency of more than 60% and emits only 330 gr/kwh
and if you use the remaining heat for communal heating, the efficiency is over 90% and the emission only 220 gr/kwh.
And its not only about CO2. It’s also to save energy and production sources for further generation and better environmental protection (e.g. less mining or land use of wind turbines) and lower energy costs.
There are three factors. 1. Per dry kg, natural gas (methane) has about twice the energy content of steam coal (I used Powder River coal for the comparison). 2. Stoichiometrically, methane produces half the CO2 per unit of combustion ( 2C+4O=2CO2, 1CH4+4O= 1CO2+ 2H2O). 3. CCGT is 61% thermally efficient while new USC coal is 41-45% depending on details. Run the numbers and CCGT produces about 36% the CO2 per MWh of electricity. Roughly a third.
A first thought here is that this would be fantastically important if true. If the work could be done to get this verified and if so accepted by the mainstream, the ability of environmental groups to leverage CAGW into forcing the world to change its lifestyle would disappear.
A second thought is that it seems to imply a relationship between the growth rate of emissions and the airborne fraction. The stability if the airborne fraction rather argues against that. However, the case of the first oil crisis is very intriguing. In the mid-70s, the increase of CO2 in the atmosphere touched zero, around about the time that global emission GROWTH ground to a halt. That sounds very like what is being postulated here. Just an anecdote though.
Lastly, we know that only a couple of percent of global CO2 is in the atmosphere. Doubling atmospheric CO2 from fossil sources just increases the size if the total reservoir by say 2%. In the long run one would expect the amount in all sinks – air, biosphere, ocean – to rise by the same percentage. In other words, for atmospheric CO2 to fall back to within a few ppm of pre-industrial – eventually. I guess the IPCC time constant of a few hundred years would say that would take a few thousand years.
Yes the 1973 Opec oil embargo is the right analogy. CO2 levels did begin to stall but emissions were not held down long enough to measure the full effect. I think the stability of the airborne fraction is as Nick says related to the continuous exponential growth in emission flux. This will reduce gradually to zero if growth is also zero indefinitely.
How else did the atmosphere survive millions of years of super volcanoes without forever rising CO2 levels?
Here is another analogy of what I think happens, with the proviso that all analogies are not fully true.
I have a very large bath of water with the plug out and the tap on. For thousands of years the depth of water has remained 28 inches because the water pressure induced flow out of the plug exactly balance the flow in from the tap. A little boy turns up and starts peeing in the bath and the level rises ever so slightly, but then he gets a hose pipe and keeps increasing the flow into the bath and the water level keeps rising. Next he gets a firehose and increases that to full throttle then he gets another, then three firehoses forever increasing the flow rate. Finally he gives up the game and goes away leaving all the hoses still running. By that time the level has risen to 40 inches and is still rising. The water pressure finally equalises the drain rate in-flow rate and the level stops rising.
The giant’s house doesn’t get flooded!
But does this analogy only work when the drain capacity (the sink) has they same flow rate as the water in (the source)?
Are you correct when you state:
In your analogy, we know the drain capacity (the sink). It is the same as the flow rate when the tap was on and water depth remained constant at 28 inches. If the drain capacity had been greater than that, the level would not have remained constant at 28 inches and the level would gradually have reduced below 28 inches. Had it been less than the flow rate when the tap was on, the level would have increased,
The reason why the level has increased to 40 inches when additional water from the fire hose(s) is added is because the drain capacity can only handle the flow rate of the tap on scenario and cannot cope with the tap on plus fire hose(s) scenario.
The issue here is whether the capacity of the sink can increase over time and if so, whether it can retain its increased capacity for long enough.
We know that in absolute terms carbon sinks are increasing in capacity over time. But if we were to stop increasing the amount of CO2, it does not necessarily follow that the carbon sinks will retain their present high capacity, and it may be that they would fall back more in line with the sink capacity as it was when CO2 was say 300ppm. If that was to happen, ie., the absolute capacity of the sinks was to fall back, then this undermines your premise.
The assumption is that the flow rate out of the fixed diameter drain depends just on pressure – so the depth. I didn’t work out the numbers and didn’t specify the area of the bath. Luckily I also didn’t specify the gravity so we might need to move the bath close to a neutron star!
Menicholas needs to revise his estimation of people breeding like flies when they move to richer countries, the exact opposite happens when people leave a state of abject poverty. Birth rates fall dramatically when people anywhere in the world are lifted out of poverty – it is poverty that creates large families because infant mortality is high and parents are frightened about being looked after in old age. High birth rates are a defence against a poor old age.
An excellent example I heard quoted recently is Bangladesh, which many people think of as a country “where people breed like flies” (a pretty disgusting way of describing poor people actually).
Well, it seems a comprehensive health programme and a gradual improvement in the lives of many people in Bangladesh has seen the birth rate in Bangladesh fall below replacement rate. A remarkable achievement but consistent with what happens everywhere.
The most objectionable part of the green movement’s lies and intentions is to keep poor people in a poverty stricken “sustainable lifestyle” and that they view human beings as a “problem”. So did Hitler and the comparison is apt. Human beings are the answer to all the questions we face, but environmentalists think they are chosen and have the right to meddle in things they clearly don’t understand or intend to choose for themselves as a lifestyle.
The world is not overpopulated anywhere, nor heading for a population meltdown.
Blue planet in green chains (new book) is where we are.
That’s exactly what we’ve seen here with turkish immigrants of the second and further generation. The birth rate is the same than of average Germany. Which also means an adaption to the western culture.
But if you keep immigrants in quarters resembling their old culture, the birth rate will be much higher.
(Me, being an original German, it seems that I have not so well adopted to the prevailing culture. I have five children… 😉 … )
Moderately Cross,
You said, “The world is not overpopulated anywhere, nor heading for a population meltdown.”
To take such a claim seriously, you need to define “overpopulated,” and get agreement. Also, not everyone is going to see it the same. Someone who grew up in rural Wyoming would probably consider Manhattan to be overpopulated. A Manhattanite might well consider an Asian city with higher population density to be overpopulated. From my point of view, I have lost a lot of freedoms to travel where I want and do what I want because of the population in the US doubling in my lifetime. If one puts no value on freedoms, then we can easily accommodate a lot more people.
“From my point of view, I have lost a lot of freedoms to travel where I want and do what I want because of the population in the US doubling in my lifetime” How so?
markl,
I could easily write an essay of the things I could do as a child and a young man that I cannot do now. When I was a boy, my dog and I had free run of woods about 1/2 mile in radius; it is now built up with homes. when I lived in Vermont in the late-’60s, it was rare to see a “No Trespassing” sign. One could hunt or fish virtually anywhere. I went back there a couple of years ago and most of my favorite haunts were now posted. The government has bulldozed the roads into former mining areas and defined them as being de facto Wilderness Areas. California and Vermont have prohibited using suction dredges for gold mining in streams and rivers. An area in California near Hollister, called Clear Creek, was off limits for years as the BLM tried to decide what to do. Now you can enter the area only with a permit, and the time allowed is limited. I could easily go on!
Clyde Spencer–have you considered that much of the restrictive access is due to liability lawyers on private land and the greens on public land? I have seen press reports of landowners with former swimming holes being told by their insurance companies to not allow swimming due to the risk of lawsuits, and one can only guess how much the greens want to keep the peons off what they regard as their land. It might not be population as such.
I see, the march of civilization bothers you. There’s more than enough room to get away from it and then some. I’m still amazed of the view from airplanes of all the natural space left in the world. One can only get the perspective from the air when you leave the cities. But yes, you can’t go home again.
mark1,
Who said anything about civilization? I appreciate technology and art. One can have civilization without large population densities. Most dynamic systems have an optimum design or parameters that characterize the system. There is a good reason that steam engines have speed governors on them. Any system without feedback loops to restrain runaway behavior is at risk of destroying itself. Yes, when in an airplane at 30,000 feet you can’t see individual people and even cars are hard to make out. But the impact of Man can be seen even in those apparently empty spaces, even from the air. One of the things that is not commonly appreciated is that (at least in the US) there is a positive correlation between urban population density and crime rates. Renowned landscape architect Ian McHarg claimed that 4/5 of all Manhattan residents had serious neuroses, and 3/5 had serious psychoses. Perhaps that explains why there are so many liberals to be found on the East Coast.
Tom Halla,
Obviously, it isn’t that population itself is directly responsible for the changes I decry. But, lawyers have an easier time earning a living when there are more people. And, increases in population create increased liability because there are more people who are inclined to damage private property or become injured on someone else’s property. It is a complex intertwining of bureaucracy and people thinking that they need to pass laws to protect people from themselves. One sees it here on this blog, where those who believe in AGW act as though they have a divine authority to tell everyone else how to live. If one studies cultures such as Japan, where a common saying is, “The nail that stands up gets hammered down.”, it should be evident that large population densities are only workable when people give up some freedoms. I understand that the Frontier is closed, but I’m not ready to live in a Brave New World.
http://www.nature.com/articles/ncomms13428
Recent pause in the growth rate of atmospheric CO2 due to enhanced terrestrial carbon uptake
I’ve modelled this before.
Basically, the natural absorption rate used to be up and down, let’s say trying to keep the CO2 level at 280 ppm, although it was always +/- 10 ppm from this level. This natural up and down use to completely dwarf our emissions until about 1950. Even in WWII when we were pumping CO2 out like crazy in weapons manufacturing, CO2 levels actually fell because the natural net absorption was greater than our emissions. By 1945, CO2 was only 310 ppm, barely above the 280 ppm equilibrium level.
By 1950, however, we started to exceed the natural absorption rate and CO2 started rising faster. At this point, the natural sink rate (trying to get back down to 280 ppm again) began absorbing 1.8% of the “excess above 280 ppm” each year. It is just a fluke that it turns out to be close to 50% of our emissions. What matters more is how much “extra there is in total” in the atmosphere, not how much we “add” each year.
1.8% of the “excess”.
Although it might be rising slightly, going from 1.6% to 1.7% to 1.8% is really not that much of a change.
If we started to slow down our emissions and then started to very slowly reduce them, the 1.8% of the “excess” per year absorption rate does not catch up to our emission rate until 2180.
Stabilize at 530 ppm. Or just 1.1C or so higher given global warming is exaggerated. We are already half way there so the amount of extra temperature lift is small and we will be “fine”.
You are basically agreeing that we can halt warming by not exceeding current emission rates.Even if that yellow line were flat in your scheme equilibrium would be reached at ~550 ppm.
Flat emission rate starting in 2030 results in CO2 stabilizing at 548 ppm around 2250.
Flat emissions starting in 2017 results in CO2 stabilizing at 536 ppm around the same time 2250.
If we never cut emissions growth, let’s say it always grows at 0.5% or 0.05% per year, the natural absorption rate will never catch up and CO2 will just keep rising. We get something close to stability with a 0.01% growth per year but this isn’t until 2300.
So, I guess some day we have to commit to a peak emission rate. It doesn’t make lots of difference to get there slowly, even by 2050, since the peak CO2 levels don’t change by that much, it just takes longer to get there.
Your basic assumption is off base: there is nothing worth the costs of the ‘solution”you offer. There is no great problem of “global warming” except the problem of the nonsense policies and vast sums of money the nonsense is costing. And holding CO2 emissions at 0 change is going to enslave billions of people. You don’t seem to support slavery, or am I wrong?
Clive, not correct. The math is wrong. If you put a certain amount of CO2 into the atmosphere each year, x, and take out x/2 at atmospheric concentration y, then if the amount you take out every year is proportional to y, the concentration y has to go to 2y to balance the amount taken up with the amount emitted.
Thus, if we are at 400 ppm, we would have to get to 800 ppm in order for uptake to equal emissions, and the process would take centuries..
No because the fraction x/2 changes with the rate of change of emissions. If the rate of change falls to zero then x/2 slowly changes becoming first 5x/8 then 2x/3, 3x/4 etc. so the process to reach equilibrium is faster.
You can increase energy production and even lower CO2 and costs. It’s all bout efficiency of production and use.
People im developing countries need no gas guzzler with 20-30 liters per 100 km. In India they sell small non-smelling motorbikes using 1 liter per 100 km.
The same is with a small gasoline generator compared to a block-type thermal power station.
Or building houses which need no or minimal A/C or heating because of their special construction.
As it so happens, India still needs air conditioning. I’m guessing you don’t know what the summers are like there. Unless you consider ‘special construction’ of poor villages.
Love the “irreversible”. Typical propagandists’ trick. Assert that something as an inalienable certainty in the hope that it will make it so, and crossing you fingers.”
They know that it is NEITHER irreversible NOR “set” but think ( hope ) that no one will spot that obvious fallacy and will thus stop resisting.
In addition to the OPEC embargo, another event worth examining would be the fall of the Soviet Union, when plummeting Soviet and East European emissions dropped 36%, stalling worldwide CO2 growth. To global warmists, why isn’t Ronald Reagan their hero?
Beginning in that same 1980s-90s timeframe, global warmists must blame themselves for the continuing rise in U.S. emissions to the present. Before green, anti-nuclear activism, U.S. nuclear power was on a trajectory that would today easily have the U.S. at 1972 emissions levels. If nukes grew enough to charge an electric vehicle fleet, the U.S. could already be at 1955 emissions levels.
If global warming were really a problem, which it isn’t, enviros have only themselves to blame.
Actually there is indeed evidence of a stall in CO2 increases during 1980s. I hadn’t made the connection but yes the collapse of the Soviet Union could well be responsible.
But no other natural source, right? Certainly, the growth in America’s economy didn’t offset that.
It is quite true that global warmists have tunnel vision. They only think of reduction of CO2 , not optimization of CO2 levels. If all sources of man-made CO2 were eliminated, which is exactly what Warmists are attempting to do, the results likely would be catstrophic even if the reduction only
stopped at the pre industrial levels existing before our illegal, unconstitutional Civil War,. Like most govt programs that are the result of pressures from an ignorant public, the likelihood of deadly side effects is pretty high, to judge from experience. And, of course, the govt never guarantees anything it does – approve drugs that kill, cars that kill, information about their own IRS laws. etc
Okay so how dynamic is the plant response and the microbial response and the plankton response? These are not small matters.
Resourceguy,
Seasonally and over short term (1-3 years) very dependent of temperature, far less dependent of increasing CO2 pressure in the atmosphere.
The net difference between CO2 uptake and release by the biosphere (plants + all depending life) can be measured by the oxygen balance: uptake releases O2, decay/digesting uses oxygen. That can be measured and gives some 1 GtC/year more CO2 uptake than release by the whole biosphere (including sea life, not directly mentioned). See:
http://www.sciencemag.org/content/287/5462/2467.short
and
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
There is still a lot of work to be done.
https://www.sciencedaily.com/releases/2016/01/160116215419.htm
Resourceguy,
The oxygen balance is an overall effect, thus includes local/regional changes like what was observed in the North Atlantic from coccoliths. Anyway, the (land + sea) plants are growing better with more CO2, thus the biosphere is increasing its uptake…
There is an error in that article: coccoliths don’t make their shell from carbonates in the water, they use bicarbonates and that is abundant enough: in seawater about 1% is free CO2, 90% are bicarbonate ions and 9% are carbonate ions… See the very nice overview of coccoliths at:
http://www.noc.soton.ac.uk/soes/staff/tt/eh/
and the chemistry involved at:
http://www.noc.soton.ac.uk/soes/staff/tt/eh/biogeochemistry.html
Clive,
This article claims that there are changes in the airborne fraction, and that since 2002 there has been a pause in the rate of growth of atmospheric CO2. This pause obviously (temporarily?) ended with the 2015-16 El Niño.
Keenan, Trevor F., et al. “Recent pause in the growth rate of atmospheric CO2 due to enhanced terrestrial carbon uptake.” Nature Communications 7 (2016).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5105171/
http://i.imgur.com/6V8kZN7.png
The researchers track this increased carbon sink to the decrease in the rate of change of plant respiration due to the temperatures pause. You talk about the oceans, but it is the plants that are doing the heavy sink work.
If this research is correct, then the stabilization of atmospheric CO2 levels can be achieved without actually having to achieve zero-growth in emissions. We could still increase our emissions by some amount, and plant growth would take care of that.
CO2 growth rate in 2015 was the highest on record at about 2.95 ppm and, in 2016, it is looking even higher at maybe 3.4 ppm. So, the study is already out-of-date once the newer numbers are plugged in.
Of course, in El Nino and warmer years, CO2 increases a little faster than La Nina and cooler years but then the study should have taken all that into account.
The question is that while the pause in temperatures was in place it appears there was also a pause in atmospheric CO2 rate of change. There are two important considerations:
– Atmospheric CO2 rate of change appears to follow not only emissions but also temperatures. Possibly by affecting the balance between photosynthesis and respiration.
– Strong ENSO distorts measurements while taking place, and data correction to ENSO effects is questionable. We don’t know what the situation is and won’t know it until a few years have passed. There is a distinct possibility that global warming remains subdued.
Both have huge repercussions for policy decision making, unless it is agenda driven and immune to evidence. If both considerations are true, then we are not facing any crisis, but a possible long term problem.
Javier,
The CO2 rate of change indeed follows all temperature variations very closely, but that levels off to near zero after 1-3 years. The main effect of a Pinatubo or El Niño is on tropical vegetation: changed rain patterns, drying out for some parts of the Amazon give extra CO2 release, together with warming oceans. That reverses when the temperature drops again. The long term (>3 years) is that vegetation is a small, but growing sink for CO2, thus while it reacts fast on temperature changes, it is not the cause of the long term increase in CO2 neither – I suppose – of a drop large enough to overwhelm human emissions if these keep increasing…
Ferdinand,
Read the article as it is open. They are not talking about the seasonal variation in CO2 that is known to follow temperatures since the late 70’s. They are talking about the long term trend between 2002 and 2014.
Javier,
Indeed interesting article. Remains to be seen in how much temperature influences the sink rate on long term. Here the calculated sink rate based on the extra pressure of CO2 in the atmosphere above the (temperature controlled) steady state:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em6.jpg
Which is nicely within the huge natural variability. The largest deviation is after the Pinatubo eruption: measurements did show that despite less incoming sunlight, the scattering enhanced photosynthesis, probably from leaves which were normally part of the day in the shadow of other leaves, but then received more light…
Javier,
Yes this makes sense. The ENSO cycle has a global effect on ocean temperatures and dissolution rates in sea water depends on temperature.
Here is a quick way to cut CO2 emissions. Shut down the economy of a country.
http://www.nytimes.com/aponline/2016/12/16/world/americas/ap-lt-venezuela-currency-chaos.html?_r=0
Modi is a friend of Trump’s, so you never noticed what happened a few days ago in India.
Is this the same NYT that said Trump was shady because he didn’t release his tax returns? Funny how no one cared about Venezuela until it became convenient.
Just a bit of looking around, it appears the IPCC and NOAA believe natural sources put about 200 gigatons of CO2 out each year and man contributes about 6 gigatons per year. Does anyone have any idea how accurate any of this data is? What are the error margins on this data? Do we have any data about how that may vary over time or change with say, a natural 1 degree rise in global temperatures.
Yes, once again I’m harping on data accuracy. It offends my science training when people try to make anything of data that has error margins so large it permits any interpretation desired.
Patrick B,
The 200 GtC (carbon as CO2) is based on the CO2, O2 and δ13C changes over the seasons. O2 and δ13C changes over the seasons are mainly from vegetation. The margins of error are huge, may be 10% or so, but not that important, as all what goes into the atmosphere is removed in the same year, plus some extra.
Global CO2 levels in the atmosphere are known to within +/- 0.2 ppmv, that is 0.05% of atmospheric content. No problem there.
Human emissions are calculated from national sales inventories (taxes!) and burning efficiencies, less accurate and its error margin is estimated around 0.5 ppmv, total amounts probably more underestimated than overestimated, due to human nature to avoid paying taxes…
The net sink rate, the difference between what humans emit and what remains in the atmosphere (the “airbrone fraction”) thus has a maximum margin error of +/- 0.7 ppmv, around the 2+ ppmv/year increase rate. Any error will be forwarded to the next year and that will level off over several years for the direct measurements, not so for the fuel use inventories.
Whatever the error margin in total and individual natural CO2 fluxes, that doesn’t influence the error margin of the global CO2 balance, which was more sink than source over the past 57 years…
Of course research is going on to make more detailed inventories of individual CO2 fluxes, both natural (over the tropical rain forests, the oceans,…) and human (tall towers measuring CO2 fluxes over large areas), but that doesn’t influence the overall balance…
One key point is the land sink isn’t even calculated. It the leftover term from taking emissions estimates, subtracting out ocean sink, looking at measured co2 increases, and if co2 increase is lower than that number, putting the difference to close the gap into land sink number. Co2 is rising less than expected.
So our margins of error on the nature side far exceed what we estimate humans contribute.
Further, what humans contribute has a large margin of error (if we are basing these calculations on sales inventories – how accurately is that reported from country to country and what about all other human activities – agricultural burning etc.?)
Sorry, I just don’t buy it with what info you provide – there’s so much slop in those numbers that I don’t believe you can tell (1) how much carbon is being cycled in nature each year or (2) what amount man is contributing, so as to make a reasonable analysis. I think the only solid number in the whole analysis is what is the CO2 in the atmosphere.
patmcguinness,
It is the reverse: the net uptake by plants is reasonably well known, based on the oxygen balance and the uptake by the ocean surface is well known by DIC (dissolved inorganic carbon) measurements, the uptake by the deep oceans is used as remainder to close the balance… Even if there are rough estimates of the uptake by following several tracers (14C from the atomic bomn spikes, CFC’s, changes in 13C/12C ratio,…).
Patrick B,
It is of zero interest for the balance how much CO2 is cycling within natural releases and uptake. All what counts is the difference between human emissions and increase in the atmosphere at the end of a full year seasonal cycle. That is currently ~4.5 GtC/year more sink than source.
If nature releases 100 GtC/year, it sinks 104.5 GtC/year.
With 500 GtC/year, it sinks 504.5 GtC/year.
With 1000 GtC/year, it sinks 1004.5 GtC/year,…
What do you thionk that most individuals and countries will do: give their sales as correct as possible, or maybe underestimate them by under-the-counter sales? That only makes that human emissions are larger than calculated and thus nature is a larger sink than calculated…
I didn’t include releases from slash and burn human emissions, as these are much too uncertain, but these too add to human emissions, making the natural sinks even larger… Moreover, we know that balance too from the oxygen measurements…
Patrick B,
I suspect that the 200 gigatons of CO2 is more like a lower bound on natural sources. There is approximately 44,000 miles of continuous spreading centers encircling the Earth. The volcanic activity is very poorly known. About 20 years ago, trees starting dying in a USFS campground on the margins of the Long Valley Caldera on the east side of the Sierra Nevada (CA). It was discovered that CO2 was killing the trees. Therefore, the USFS closed the campground out of an abundance of caution lest some campers not wake up in the morning. I can’t believe that that particular location is the only one that is giving off lots of colorless, odorless, invisible gas. If other volcanoes are emitting CO2 above the timberline, there would be little to give it away. There are known to be soda springs throughout the world, and there are known to be massive CO2 seeps in the southern ocean.
For more information on the magnitude of the lack of information: https://www.yahoo.com/news/underwater-volcano-eruption-observed-real-054244071.html
Based on a quick review, and I could have missed it, but missing from this is a consideration of the effects of biology on the oceans. Not only is water buffered chemically, but it is buffered all over the surface of the oceans by photosynthetic organisms, prospering on the conversion of CO2 to O2. That amount of life in the Oceans would increase in response to increasing CO2.
Yes and that is where Ferdinand comes unstuck.
Ever seen a 100m limestone cliff that stretches over a 1000km ? And thats just one of them. What was that ? Just a cyclical predictable “sink” event.
You could do a back of the envelope volumetric calculation on known Miocene Limestones to reduce these sink rate calculations to irrelevance.
Taking into account the time span, the cliffs needed millions of years to build up: about 0.1 mm/year in average, Current sink rate of all organics + skeletons is ~6 GtC/year, largely compensated by upwelling waters which move CO2 enriched waters back to the surface…
Current sink rate of all organics + skeletons is ~6 GtC/year, largely compensated by upwelling waters which move CO2 enriched waters back to the surface…”
Largely, but not totally, because that CO2 was/is at 290ppm equivalent, so we gradually are putting more CO2 into the deep oceans, at the 2.5GtC/year rate, increasing as the gap between Co2 in atmosphere and Co2 in deep oceans, gets better (apparently linear rate).
Clive,
Your CO2 emissions versus CO2 Levels graph shows CO2 levels via direct measurement as going up and down (some years lower than previous years) through the recent decades. Is that a really a rate the graph is showing (as in a delta CO2/yr)?
Because as I’m sure you know, by the MLO record no year’s average measured CO2 has been lower than a previous year’s average.
You’re right – that was a bad choice of graph to use. The intention was just to show 2 curves on the same scale where Carbon content of the atmosphere increases at half the rate of carbon emissions.
http://www.drroyspencer.com/wp-content/uploads/simple-co2-model-fig01.jpg
Joel, that graph shows the atmospheric carbon growth RATE. And the growth rate DOES fluctuate from year to year. Sometimes up, sometimes down. But on the whole, more up than down…
It seems to me that we should want to reach atmospheric optimum CO2 levels, apparently 600-800ppm. This would help the impoverished throughout the planet, and likely not be a less stable level. Those who oppose any CO2 increase appear to be more interested in their own income than helping impoverished.
Excellent article. The key observation here is that ocean and the biosphere are carbon sinks and are at different levels of equilibrium. In particular the oceans have 37000 Gt of co2 and except for surface are at 290ppm equilibrium, and so there is capacity to soak up a lot of carbon front the atmosphere, turning co2 into carbonates and getting eaten by plankton then sent to the deep ocean. The key is the rate, and the rate seems to have increased linearly relative to difference of co2 above 290ppm preindustrial baseline. I calculated that the ocean sink could run at current rates for over 200 years at the current 2.5 Gt C per year level before saturation.
The dK calculated estimate value should be determined by this co2-atm and co2-ocean difference, as le chetaliers principle is the driving factor. So I agree with the main thrust but question some of the calculation. You need to base equation on le chetaliers the factor in rate limits on absorption and for ocean apply revellers factor. My own calculation is that steady state man made emissions at current levels would take us to 460 to 480ppm and then level to steady state. To summarize ocean sink per year=k*(co2-atm – co2-ocean), where co2-ocean is around 290ppm. The higher co2 goes the bigger sinks get, they are a big negative feedback and date shows they remain so for now.
Revelle factor is correct term, regarding how much co2 gets taken up by ocean and becomes carbonates. Danged autocorrect made it Revellers. Well Merry Christmas wuwt Revellers!
Thanks,
We have good agreement. Yes we can argue about the details and yes I have grossly over-simplified things, but the overall picture is clear. We have to counter the propaganda that emissions have to fall to zero by 2050. They don’t because first all we need to do is stabilise emissions which gives us plenty of time to plan an effective energy policy. This message can stop the profligate wasting of economic resources today for no net public benefit. Hence the title ‘ A Hiding to Nothing’. The bookies will take all the money and the dissapear.
What you’ve got here, Clive, is a simple relaxation model. Basically, what you are saying is that CO2 concentration is achieved by a balance between the inflow and an outflow that is proportional to the current level.
dC/dt = -C/tau + u
where u is the input rate, and tau is a time constant. At equibrium, with u constant, C = u*tau.
We can disaggregate u into natural and anthropogenic terms, u = a + n. Since the equation is linear, we can then disaggregate C into terms Ca and Cn such that C = Ca + Cn, and
dCn/dt = -Cn/tau + n
dCa/dt = -Ca/tau + a
But, this means that
d/dt(Ca/Cn) = (n/Cn)*(a/n – Ca/Cn)
If a is less than from fractional value of n, say f*n, then
d/dt(Ca/Cn) (is less than) (n/Cn)*(f – Ca/Cn)
That means that, if Ca/Cn starts out less than f, it can never grow greater than f, as the rate of change at that point is bounded above by zero.
Common estimates of f are about 3%, or 0.03. That would mean that, if Cn = 280 ppm, Ca can never be greater than 0.03*280 = 8.4 ppm. The claim that Ca = 400-280 = 120 ppm then falls flat on its face. That is 120/8.4 = 14.3X greater than it could possibly be using this model.
The conclusion that ineluctably follows is that the great majority of the observed rise is due to natural phenomena.
I am not sure I fully follow your logic. However, I don’t think tau is a constant. It depends on CO2 partial pressure. Unfortunately we are responsible for the rise in CO levels but these are also being offset by natural responses. We just need to stabilise emissions to a fixed level that best meets our short term needs while we develop new (most likely nuclear) energy supplies.
Clive,
Tau is constant over the past 57 years, about 51 years e-fold decay rate for any excess CO2 above steady state or about 35 years half life time. The response of the (oceanic) sources/sinks disequilibrium is surprisingly linear over the full period of accurate measurements.
The error in Bart’s reasoning is that he mixes two largely independent processes as being similar. That is not the case: the largest natural fluxes are largely temperature dependent: mostly (NH extratropical forests) seasonal, partly differential (equatorial release vs. polar uptake), while the removal of any extra CO2 injection, whatever the source, is largely pressure dependent…
There is hardly any influence of pressure on the seasonal CO2 fluxes and hardly any influence of temperature on the sink rate of any extra CO2 in the atmosphere above steady state…
It does not matter if tau is constant or not. The equation
d/dt(Ca/Cn) = (n/Cn)*(a/n – Ca/Cn)
is independent of tau, and the bound holds regardless.
Bart,
Two (in fact several) near independent processes at work with different tau:
dCn+a/dt = -ΔT/tau1
dCn+a/dt = -ΔP/tau2
tau1 is for temperature dependent processes and is a matter of months (except for the deep oceans). That gives the bulk of the fluxes over the seasons and smaller fluxes for year by year variability.
tau2 is for pressure dependent processes and is a matter of decennia, no matter what caused the increase above the (temperature dependent) steady state.
The variabilty over the seasons and 1-3 years is practically independent of the total amount (pressure) of CO2 in the atmosphere.
The average net sink rate is largely independent of temperature over periods longer than a few years.
To make it more complete (not exhaustive):
dCn+a/dt = – ΔT/tauT1 – ΔT/tauT2 – ΔT/tauT3 – … – ΔP/tauP1 – ΔP/tauP2 – ….. + a + n1
Where n1 = the small, not temperature related CO2 releases by nature above equilibrium (like volcanic vents), not the total natural emissions, as these are caused by -ΔT/tauTn…
Natural processes can be both pressure and temperature dependent (oceans, CO2 uptake by plants), or only temperature dependent (CO2 release from organic decay by bacteria and fungi), each process with its own decay rate for pressure and/or temperature…
This is mathematical gibberish, Ferdinand. But, whatever idea it is you are trying to express, it would not matter anyway, because the same equations affect Ca in equal measure.
Bart,
It may be mathematically wrong, but the basic point is that the natural releases and sinks are mainly temperature dependent and that human emissions don’t influence these processes in the same way: they increase the CO2 pressure in the atmosphere and therefore increase the sink rate in all pressure sensitive processes.
Natural releases don’t influence the sink rate because they are caused by temperature. For the ocean surface in the same direction, for plants even reverse with temperature: higher temperatures in spring and summer give more uptake by plants and lower CO2 levels in the atmosphere over the warm seasons. Plants are dominant over the seasons. Thus there is zero extra pressure from natural sources in the atmosphere to store more CO2 in plants or oceans as plants already use too much CO2…
Thus your formula that natural and human releases are threated equally is only right for the natural emissions above the steady state at any moment of time, not for the changes in equilibrium level itself, which are driven by temperature changes.
440ppm is too low. Something around 1,500ppm (0.15%) would normal for the late Phanerozoic. But when the interglacial ends, it’ll drop by half. I’d say 2,000ppm (0.2%) should be the target..
Thanks, Clive Best, for this post. I suspected a limit on atmospheric CO2 with a constant energy output, but had’t read anything on the subject.
My suspicions arouse from high school chemistry, and personal observation. After my 20s, when I was lifting weights and jogging regularly, I cut the strenuous exercise in my 30s, while eating as much or more than I had before. Needless to say, my weight did not increase indefinitely, but stabilized at a somewhat higher weight.
Alan,
That is a pretty good analogy! The moral is to always to reach an optimum balance.