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THIS POST IS A CRITICAL REVIEW OF AN ASSESSMENT OF AGW CLIMATE CHANGE BY THE ECONOMIST MAY 9 2020 [LINK] WITH THE TITLE:

HUMANITY’S IMMENSE IMPACT ON EARTH’S CLIMATE AND CARBON CYCLE: MUCH NEEDS TO BE DONE FOR THE DAMAGE TO BE REVERSED 

THE FULL TEXT OF THE ARTICLE APPEARS BELOW AT THE END OF THIS POST. 

PART-1: THE CONTENT: WHAT THE ARTICLE SAYS

1. The article says that 85% of our energy of our industrial economy comes from fossil fuels namely petroleum 34%, coal 27%, and natural gas 24% and that the other 15% comes from RENEWABLE sources namely nuclear, hydro, and “other”).
2. In this way, the industrial economy causes 9.5 gigatons of carbon per year to be taken from under the ground and added to the atmosphere.
3. The implication of the statement in item 2 above is that all of our the carbon in our fossil fuel emissions ends up in the atmosphere and thereby increases atmospheric CO2 by 9.5 gigatons per year.
4. Through its effects on the plants, animals and microbes which make up the biosphere, on the climate and on the oceans, this industrial flow of carbon links the Earth’s distant geological past to its future over millennia to come.
5. This unnatural man made oddity that connects the past of the planet to its future is the evidence that with their Industrial Economy, the humans have a power over nature and the planet itself. This condition is described as a new geological epoch to be called the Anthropocene in which humans are the dominant geological force of the planet. A critical evaluation of the Anthropocene argument is presented in a related post [LINK] where the relative insignificance of humans on a planetary scale is presented.
6. Nature’s carbon cycle is in “dynamic equilibrium” where carbon flows to and from the atmosphere are balanced so that even though life on earth produces more carbon dioxide than the industrial economy, there is no accumulation of CO2 in the atmosphere and therefore no rise in atmospheric CO2 and no natural global warming because respiration is balanced by photosynthesis. The injection of fossil fuel CO2 into the carbon cycle causes an unnatural perturbation of the carbon cycle with carbon taken from fossil fuels that is millions of years old and not part of the current account of the carbon cycle. This injection of EXTERNAL carbon into the carbon cycle is an unnatural perturbation of the carbon cycle that imposes an imbalance and causes atmospheric CO2 to rise and and that in turn causes anthropogenic global warming or AGW by way of the greenhouse effect of CO2.
7. The carbon cycle has been intensified by fossil fuel emissions and a side effect of this intensification is a rise in the flow of CO2 to the ocean and that has caused sea water to become more acidic. The process of ocean acidification will probably be very damaging to some ocean ecosystems including coral reefs. Ocean acidification is as frightening as climate change.
8. The Economist’s analysis ends with a wandering and incoherent rant about various earth science engineering and chemical engineering ideas for humans to remove  carbon dioxide from the atmosphere and control atmospheric CO2 concentration now that we are in the Anthropocene and humans are in control of the planet but this pie in the sky discussion goes nowhere and the author thus concedes that maybe it isn’t the Anthropocene after all for if it were humans would be able to engineer atmospheric CO2 concentration to meet the “Paris Agreement targets”. The confusion of the authors about the inability of the Anthropocene masters of the planet to control atmospheric CO2 concentration underscores arguments presented in a related post that humans are not in control of the planet and are in fact a rather insignificant feature of it [LINK] . 

PART-2: CRITICAL COMMENTARY ON THE CONTENT

1. The content lists nuclear, hydro, and “other” as renewable energy sources. This assessment is grossly at odds with that of mainstream climate science where the portfolio of renewable energy consists entirely of what must be implied in the “other‘ classification of the Economist, namely wind, solar, biomass, and bio-fuel. No mention is made in the call for renewables by climate science, of nuclear or hydro with the possible exception of pumped hydro as a battery to store wind and solar energy.
2. It is claimed in the content that fossil fuel emissions of the industrial economy are 9.5 gigatons per year of carbon and that in this way, the industrial economy transfers 9.5 gigatons of carbon from under the ground to the atmosphere where it accumulates and causes atmospheric CO2 to rise. This is not what climate science says. What we find in climate science is that, in the context of an annual accounting of the carbon cycle, it is estimated that about half the carbon in fossil fuels goes to the atmosphere, the so called “airborne fraction“, and increases atmospheric CO2 concentration; and that the other half goes to other carbon cycle sinks, mostly photosynthesis and the ocean.
3. It is noted in a related post [LINK] that the the determination of the “airborne fraction” as 50% derives from circular reasoning and that in the context of large uncertainties in unmeasurable carbon cycle flows that are an order of magnitude larger than fossil fuel emissions, it is not possible to detect the presence of fossil fuel emissions. In yet another related post [LINK] , we show that the correlation between emissions and changes in atmospheric composition implied by the airborne fraction assumption in climate science is not found in the data. Therefore, in essence, we don’t have the evidence we need to support the assumed causation of observed changes in atmospheric composition by fossil fuel emissions.
4. The content says that the fossil fuel emissions of man’s industrial economy links the distant geological past of fossil fuels to the present and to a distant future yet to come for millennia and that this linkage is unnatural and dangerous for both nature and for man himself. This assessment is grossly inconsistent with how nature works. All of nature is connected to a distant past and will continue to be connected indefinitely into the future. The geological and biological history of the earth is a sequence of cause and effect for billions of years with the geology and the biology also connected as it was the geology that gave us the carbon from the mantle from which carbon lifeforms came about and gradually evolved into a diverse portfolio of life on earth of which humans are a part. For example, the geological and biological evolution of the planet is profoundly connected to events like the End Triassic plate tectonics extinction event (ETE [LINK] ) such that the world that we live in now can be considered to be a creation of the ETE. To evaluate human impacts on nature in the same way is a gross over-estimation of the role of humans by self centered and egotistical humans.
5. The further claim in the content, that industrial economy humans and their fossil fuel emissions are now the primary geological force of nature in control of the planet in a new geological epoch called the Anthropocene, is discussed in some detail in a related post [LINK] . There it is shown that the crust of the planet is where we have things like atmosphere and oceans and climate, and life on earth, and the humans, and the industrial economy of the humans spewing fossil fuel emissions. However, in terms of total mass, the crust of the planet is an insignificant portion of the planet. Also, it is shown that life on earth is an insignificant portion of the crust; and that humans are an insignificant portion of life on earth. Therefore, humans are insignificant on a planetary scale. The assessment of their alarming planetary impact is likely to be a product of the ego of humans that aspires to a lofty planetary role as the caretaker of nature and of the planet itself perhaps soon to be extended to the solar system by way of the space age of human technology.
6. The assessment that carbon in fossil fuel emissions was removed from the atmosphere millions of years ago and that therefore this old carbon is not part of the current account of the balanced carbon cycle and that therefore the injection of this old carbon into the atmosphere causes a perturbation of the carbon cycle, rising atmospheric CO2, and anthropogenic global warming is surely a reasonable theory but  it has no empirical evidence. First, carbon cycle flows are an order of magnitude larger than fossil fuel emissions and their flow cannot be directly measured but are inferred. As a result there are large uncertainties in the estimates of their flows. Even the uncertainty in these flows requires guesswork, but the IPCC has estimated and published some of these uncertainties. In a related post it is shown that when these IPCC uncertainties in natural carbon cycle flows are taken into account, the much smaller fossil fuel emission flows cannot be detected [LINK]. Therefore,, we don’t really know what the impact of fossil fuel emissions is on the carbon cycle. The 50% airborne fraction used in climate science is thus an exercise in circular reasoning because it is derived from the observed increase in atmospheric CO2 concentration and then used to explain the observed increase in atmospheric CO2 concentration. In yet another related post we show that the correlation between emissions and changes in atmospheric CO2 concentration implied by the airborne fraction theory is not found in the data [LINK] . In other words, the relationship between fossil fuel emissions and changes in atmospheric composition is assumed by climate science but with no empirical evidence to support that assumption.
7. That some of the fossil fuel emissions are ending up in the ocean and causing ocean acidification that is damaging ecosystems may be “frightening” but this relationship between emissions and ocean pH has no empirical evidence and the proposed “frightening” extent of such acidification is not possible given the relatively small amount of carbon available in fossil fuel emissions. In a related post we show that correlation and mass balance analyses do not provide evidence to relate changes in oceanic pH to fossil fuel emissions because the observed changes in the ocean requires much larger carbon flows than what fossil fuel emissions can provide [LINK] . The ocean is a little too big for the relatively tiny amount of fossil fuel emissions to cause a measurable change in its pH.  In other related posts we show that the ocean has access to natural geological sources of carbon in amounts that are orders of magnitude larger than fossil fuel emissions [LINK] [LINK] .
8. CONCLUSION: The Economist’s analysis of the climate change issue seems strangely ill informed and poorly thought out having dug themselves a trap with the Anthropocene argument that humans are now in control of the planet but without the controlling ability to control atmospheric CO2 concentration. Perhaps economists are better at economic analysis than they are at climate change analysis. 

PART-3: FULL TEXT OF THE ARTICLE

It is all, in the end, a matter of chemistry. Carbon dioxide is a form of what chemists call inorganic carbon—a simple molecule that is pretty inert. Fossil fuels are made of carbon in its organic form—often complex molecules that are far from inert. Combustion turns these organic complexities into inorganic simplicities: carbon dioxide, water vapour and heat. Of the energy that people pay for (as opposed to the energy that comes from burning firewood) 34% comes from burning oil, 27% from coal and 24% from gas. Nuclear power, hydroelectric power and all other renewables combined provide just 15%. The result of all this fossil fuel use is a modern industrial economy and an annual flow of 9.5bn tonnes of carbon out of the ground and into the atmosphere.

Through its effects on the plants, animals and microbes which make up the biosphere, on the climate and on the oceans, this industrial flow of carbon links the Earth’s distant geological past to its future over millennia to come. It is the single clearest piece of evidence for the idea that humans now have a power over the Earth as great as the forces of nature, and that their use of this power has opened up a new geological epoch that some scientists call the Anthropocene.

To appreciate the importance of this industrial carbon flow, you have to understand the carbon cycle in which it sits. At first, this context seems reassuring. Almost all microbes, and all animals, get the energy that they need for life from breaking up food made of organic molecules. The flame-free, internalised form of combustion by which they do so, which biologists call respiration, produces much more carbon dioxide than industry does. But respiration has a counterpart: photosynthesis, through which plants, algae and some bacteria use sunlight to turn inorganic carbon back into organic molecules. These new molecules are the raw material from which almost all living things on Earth are made; the sunlight stored within them is the source of all the energy that is released through respiration when those living things are eaten.

The other great flow of carbon dioxide into the atmosphere is similarly balanced. Carbon dioxide dissolved in seawater naturally diffuses into the air above. Carbon dioxide in the atmosphere dissolves into seawater. Left to themselves, the two flows balance (see diagram).

These flows create a system in what is called dynamic equilibrium; if you push it away from current conditions, it pulls itself back. If atmospheric carbon-dioxide levels go up, the rate at which carbon dioxide dissolves into the “sinks” provided by the oceans and plants will also, all things being equal, go up. This reduces the surplus, restoring the status quo. Until the 19th century this dynamic equilibrium had kept atmospheric carbon-dioxide levels pretty stable for most of the 10,000 years since the end of the most recent ice age.

The plants-and-food branch of the carbon cycle, though, is not quite perfect. Like the little bit left in the corner of the sardine can that you can’t get out, not all the organic matter made through photosynthesis gets used by creatures that respire. Some ends up buried in sediments instead.

The amount of carbon which leaks out of the biosphere this way is tiny compared with the flow returned to the atmosphere. But the leak has gone unstopped for a very long time, and that has allowed the Earth’s crust to build up a significant store of organic matter. Now human industry’s use of the most concentrated and readily available deposits of these fossil fuels has returned to the carbon cycle in a couple of centuries a fair fraction of what was stashed away over hundreds of millions of years. It is the addition of this new source with no new sink that has knocked the cycle out of whack.

The world’s seas and plants have tried their best to keep things in equilibrium, responding to rising levels of carbon dioxide by stashing more away in the biosphere and oceans. They suck up roughly half of all the extra carbon dioxide that industry puts into the atmosphere. But that is as much as they can do. And so the amount in the atmosphere grows.

This intensification of the carbon cycle has side-effects. Plants fed with extra carbon dioxide tend to grow more, if circumstances allow. Current estimates suggest the global rate of photosynthesis is 3-7% higher than it was 30 years ago; satellite images show the Earth is getting greener. Such “carbon-dioxide fertilisation” has improved the yields of some crops, and the growth of some forests and other ecosystems. This is not enough to compensate for the damage climate change does to agriculture by higher temperatures and altered rainfall. But, on balance, it is hard to see it as much of a problem.

The same cannot be said of the increased flow into the ocean sink. More dissolved carbon dioxide makes seawater more acidic. How bad this acidification will prove is open to debate. But the process will probably be very damaging to some ecosystems, including reefs already stressed by rising temperatures. Even if fossil-fuel use were not warming the climate, this acidification would in itself count as a frightening global change.

The growth of the two carbon sinks is also, left to itself, unsustainable. Warm water absorbs less carbon dioxide than cold water. So as the oceans warm their ability to offset emissions weakens. As to the land sink, higher temperatures speed up microbial respiration, especially in soils, more reliably than higher carbon-dioxide levels speed up photosynthesis.

The Paris agreement of 2015 calls for increases to the atmosphere’s carbon-dioxide level caused by fossil fuels to end by the second half of this century. Even if that deadline is not met, some mixture of policy, catastrophe and/or resource depletion will eventually bring the rise to an end. The flows of carbon between the atmosphere, oceans and biosphere will then come back into balance.

But the equilibrium thus restored will not be the pre-industrial one. The carbon-dioxide level will settle down not far short of whatever the 21st century’s peak level turns out to be. Which means that temperatures will stay high, too—with all that entails for crops, ice caps and the like.

This plateau will eventually subside. The erosion of the Earth’s crust exposes silicate minerals that react with carbon dioxide, eventually producing solid carbonate minerals from which the carbon cannot readily escape. But this “chemical weathering” works on a much longer timescale than the sinks. Geochemists think it would take 1,000 years for a post-fossil-fuel carbon-dioxide level of around 550 parts per million to be brought back below today’s 415ppm towards a mid-20th century level of 315ppm.

Going backwards
What, though, if the Anthropocene transitioned from a past dominated by anthropogenic carbon sources to a future characterised by anthropogenic sinks? There are two reasons why this might be appealing. One is that some fossil-fuel emissions may be very hard to eliminate from the economy. If they could be counterbalanced by “negative emissions” that take carbon dioxide out of the atmosphere at a similar rate, the Paris goal of stopping any further increase to the carbon-dioxide level would be far easier to meet.

The second attraction of the idea stems from the other Paris goal, that of keeping the global temperature increase, compared to pre-industrial times, well below 2°C. Doing this simply by reducing emissions would require much steeper cuts than any seen to date, and they would have to continue for decades. If the world developed negative-emission technologies, more gentle emissions cuts in the near future could be made up for by negative emissions later on, which would bring the carbon-dioxide level back down from its excessive peak.

Some forms of negative emission look fairly benign: farming in ways that make the soil richer in organic carbon; restoring degraded forests and planting new ones. More ambitious is the idea of harnessing photosynthesis to industry; growing plantation crops, burning them to generate electricity and sequestering the carbon dioxide given off underground, rather than letting it out into the atmosphere, an approach called bioenergy with carbon capture and storage, or beccs.

Then there is the idea of stripping carbon dioxide out of the atmosphere with renewably powered open-air chemical engineering: “direct air capture”, or dac. And there is also the possibility of helping along the chemical weathering process by grinding up silicate rocks into fine dusts, thus speeding up the reactions that store carbon dioxide away in stable minerals.

There are two big problems with these ideas. One is the scale at which they need to operate to make a difference. Imagine that in 2060 the world had, through a vast effort, renounced 90% of its fossil-fuel use. To offset the remaining recalcitrant 10% would still require a sink capable of soaking up about 1bn tonnes of carbon a year. The industrial systems for taking carbon dioxide from the air currently on the drawing board operate at barely a thousandth of that scale. Creating such a flow through photosynthesis would require a plantation about the size of Mexico.

This leads to the second problem. Imaginary backstops are dangerous. If countries build negative emissions into their thinking, they will cut emissions more slowly on the basis that any overshoot can be mopped up later. But they will not necessarily undertake the huge efforts required to make those negative emissions a reality. The Anthropocene fact that humans are now integral to the processes of the planet does not mean that they can change those processes