Monday, April 30, 2012

Methane and the disturbed Carbon Cycle

A look at recent studies in climate science

Guest Post by Philip Harris
(a longer version of this post is available here)

Philip Harris is a retired plant scientist based near the Scottish border in the UK. He has worked for government agencies in such areas as food safety and plant quarantine and disease diagnostics, and on risk identification and risk assessment. From 1997 to 2006 he worked for the EU on 'capability-building'  science projects in ex-communist countries of Europe.
The Kilda Basin, located between Scotland and Norway. This basin may have suddenly released such a large amount of methane in the atmosphere that it generated the "Paleocene-Eocene thermal Maximum" (PETM), an episode of rapid global warming that took place about 55 million years ago. Could this episode be a model of what may happen in the near future with the rapid release of methane observed today? This point is discussed by Philip Harris in this post. (image above from Nisbet et al. 2009 - ref (7))


Preface by Ugo Bardi

A few months ago, I published a post on "Cassandra's Legacy" titled "Methane Hydrates: the next communication bomb" where I argued that the possibility of a catastrophic release of hydrates (the so-called "clathrate gun hypothesis" is going to have a massive impact on the debate on climate change. In this and in other posts, I have been arguing that we are facing a task that we cannot leave to climate scientists alone. All of us must tackle the issue; understand it, and give our contribution to alert everybody of the risks ahead. It is only in this way that the problem can gain the attention of the public and policy makers together. These posts of mine led to a response by Philip Harris, retired plant scientist, who agreed that we need to work on this subject and who offered to produce a paper where he summarizes his personal research on the subject. In particular, Phil has examined the "Kilda Basin hypothesis."  This term refers to a region in the Atlantic Ocean, approximately between Scotland and Norway. The idea is that the basin may have suddenly released large amounts of greenhouse gases and forcing the disastrous episode of global warming known as "Paleocene-Eocene Thermal Maximum" (PETM). The story is described by Nisbet et al. in a 2009 paper in "Nature Geoscience" (7). What is happening now with the human-caused release of greenhouse gases may be similar to the conditions that led to the PETM event.
What follow is a short version of Phil Harris' work, a complete version can be found on the site of ASPO-Italy.

Introduction: a personal quest

“Ugo … 
At least I should try. If we understand sufficiently the science story, we should teach and encourage others to enquire.
The importance of the non-condensing gases becomes clearer.
Through our own intellectual struggle we occasionally find a dawning reality.
The mental act of adding modern CO2 and CH4 numbers on to that figure of Hansen & Sato's was such a moment for me.
It also prepared me for The Kilda Basin Conjecture - the idea that the warming event called "PETM" was generated by a sudden release of greenhouse gases from the Kilda Basin, located in the North Atlantic.
We are becoming already an exhaling ‘Kilda Basin’?
This stuff got a 'human reaction' from me, which might be communicable.”


The methane problem

Recently Ugo Bardi raised the matter of methane and the fact that compared with geological history, the present level in the atmosphere of this potent ‘greenhouse-gas’ is exceptionally high. We see methane bubbling from the arctic margins. We know the present level is around 1800 parts per billion (1.8ppm); more than 2.5-fold the pre-industrial level. We know this rise has been sudden and that most of it occurred in the 20thC up to about year 1990, and that interestingly for a rapidly oxidised molecule, this high level has been sustained, and lately has begun to increase again. After a brief discussion with Ugo, I decided to attempt an update of my own knowledge. I needed also to integrate knowledge of methane with understanding the role of the chief non-condensing ‘greenhouse-gas’, carbon dioxide.

What I have experienced in the last few weeks has not been exactly a ‘Damascene’ moment, but as we all know, if we struggle hard enough intellectually, then a new awareness of reality can dawn. Twenty and more years ago I had collected scientific papers that addressed the importance of atmospheric methane. This gas was already well understood to be part of the more general human-induced inflation of radiative forcing in the climate. We have dramatically increased the non-condensing ‘greenhouse’ gases in the earth’s atmosphere. It is a matter of fact that we experience extra radiative forcing (net trapped sunlight) because of these ‘trace’ gases released by industrialisation and in the case of methane also arising from the recent large extension of agriculture. We have for decades been able to watch the ongoing rise of carbon dioxide (CO2) measured continuously by NOAA Observatory in Hawaii. Methane (CH4), the second most important of the non-condensing gases was known to have increased even more dramatically from pre-industrial levels. All this we knew decades ago. And, already twenty years ago the ice and sediment records were beginning to tell their stories of past climates.

Where has the relevant science gone over the intervening 20 years? Can I interest you, the reader, in my recent journey of discovery, and particularly in what for me were the illuminating and I hope insightful moments?

I wrote a longer article in order to convince myself that I had sufficiently grasped the later scientific evidence and scientific arguments, and I used many quotes from and references to scientific papers: this longer article is available at the ASPO website if you want to engage more with the details. I would value additions, comments and corrections.

Firstly I familiarised myself again with the carbon cycle (‘sources and sinks’) and then with the way it has changed over geological time, so that I could better place in this context the vast “meta-stable” reserves of solid methane gas hydrates, otherwise known as ‘clathrates’. These are sequestered but potentially gaseous carbon deposits, which have been part of the earth’s carbon cycle for hundreds of millions years; maintained possibly continuously, if dynamically, over this unimaginably long history. More recently, clathrates have been part of a relatively stable, though oscillating, carbon cycle and climate(1). These oscillating cycles have been ‘normal’ for a million or more years. As the climate oscillates, so does the carbon cycle along with the consequent hydrological cycle. The earth during this period has oscillated from glacial era to part-glacial era and correspondingly the sea level has gone up and down by some 120 to 130m. Our kind has become used to the latest extended warm period since the sea level last rose by about 120m about 10,000 years ago.

We can ask, though, how the great stores of methane clathrates have interacted with climate changes not only in the last million years, but also much further back. What do we know from the records of longer geological time? Calculations have revealed that even a small fraction of the probable reserves if they were suddenly released into the atmosphere could overwhelm the photo-oxidation (OH’) capacity of the atmosphere and thereby persist for long enough to cause a great pulse of warmth from trapped sunlight. Indeed it was a long time ago, about 55 million years ago, but something like this actually seems to have happened. The result then was to initiate a disordered carbon cycle that lasted 100,000 years and a ‘thermal maximum’ climate we would not recognise – the PETM (2).

1st personal insight:
comparability of the present day ‘trace’ gases with the remote geological past

During the PETM both CO2 and CH4 were maintained over millennia at very high concentrations; methane at perhaps 5 to 10-fold those of the recent pre-industrial concentrations. Numbers matter. To recapitulate; CH4 levels in the last few decades are 2.5-fold higher than pre-industrial concentrations. I will return to the PETM but let me introduce another ‘moment’ that was for me one of increased clarity.

2nd personal insight: the importance of the non-condensing ‘trace’ greenhouse gases becomes clearer.

Snowball Earth and the non-condensing gases

There was, a very long time ago, a Snowball Earth; a period that ended around 635Ma. Gas hydrate releases are mentioned as one of putative positive feedback mechanisms that brought this phenomenon to an end.

(3) Hypotheses accounting for the abruptness of de-glaciation include ice albedo feedback, deep-ocean out-gassing during post-glacial oceanic overturn or methane hydrate destabilization.

Scientific discussion continues about this interesting period, but for our purposes it is worth noting the reasons why we do not have a snowball earth.

(4)  Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth's atmosphere. This is because CO2, like ozone, N2O, CH4, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapour can and does. Non-condensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapour and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO2 and the other non-condensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state (emphasis added).

Methane is only a transient ‘trace’ gas, but we know that in recent decades it supplies about 20% of the extra net radiative forcing that results from ‘our’ extra greenhouse gases in the atmosphere; a significant addition to the total greenhouse effect.

3rd personal insight: the enormity of the last few decades

Glacial and Inter-Glacial Periods over the last 800,000 years

Before our present Holocene interglacial there was the previous warmer Eemian (+1°C, 125,000 years ago), and before that the also warmer Holsteinian (400,000 year ago). Greenhouse gases in the atmosphere rose then to levels similar to recent pre-industrial Holocene levels. 

Figure  800,000 years of CO2 and CH4 concentrations correspond with timing of glacial/interglacial temperature fluctuations; from Hansen & Sato, 2011

Personally, I only get the enormity of what has happened in the last few decades if I superimpose present CO2 and CH4 concentrations (respectively 392ppm and approximately 1800ppb (5)) on the end of the above figure (Hansen & Sato,2011 (6)). Methane immediately after the end of the Younger Dryas event was at ~700ppb; dropped to ~600ppb by 5000 years ago; climbed to >700 again by the year 1750.)

I encourage you to re-enact my mental process and superimpose your own visualisation.

4th personal insight: comparisons over 5 million years are valid enough

A mere 5 million years ago in the Pliocene the ocean was about 25m higher than today, but temperatures were not greatly higher than those in the inter-glacial Eemian 125,000 years ago, or those just now. However, CO2 levels back then in the Pliocene were higher than in the more recent one million year glacial period; i.e. higher than pre-industrial levels in our Holocene (280ppm), but probably comparable with those of the last 10 years at 380ppm. (See discussion in Hansen & Sato, 2011 ref. 6). Quote: 
And regardless of the precise temperatures in the Pliocene, the extreme polar warmth and diminished ice sheets are consistent with the picture we painted above. Earth today, with global temperature having returned to at least the Holocene maximum, is poised to experience strong amplifying polar feedbacks in response to even modest additional global mean warming.

This is our world as it is emerging. ‘Our’ CO2, though, has the potential to go much higher than Pliocene levels, and is coupled at the same time with a sustained exceptional methane level.

I have collected a number of up-to-date studies that look at abrupt (millennial scale) warm and cold climate events that occurred both during and at the termination of the last glacial maximum. These studies consider the raised level of methane (see again the figure above), that accompanied both the earlier warmer excursions and, finally, the glacial termination. The studies include an assessment of the stability of marine clathrates and whether sudden release of methane might have initiated the warm periods. Details are in my longer article located here.

Despite conjectures about the ‘Clathrate Gun’ (a sudden instability of very large clathrate deposits) having initiated positive feed-back changes and thus acted as a prompt cause of rapid climate warming events, marine hydrates actually appear to have been generally stable during the glacial and inter-glacial periods of the Pleistocene. Nevertheless, clathrates over this time have been to a degree dynamic, especially in the Arctic. They either form or are released in response to changing pressure/temperature combinations as the temperatures of both ground and ocean adjust to the prevailing cooling or warming trend and as the sea level falls or rises;

 … I quote from my longer article:

There is much of interest to be discussed, but the take-home point just now might be that although past thermal shocks must have gradually de-stabilised some CH4 gas hydrates, thus both increasing chronic methane release and adding to warming events during de-glaciations, these shocks did not cause sustained runaway temperatures during the subsequent inter-glacial periods. Further methane-induced positive feedback did not happen. Vast reserves of CH4 and other near-surface carbon still remained. For example; the previous Eemian inter-glacial 125,000 years ago achieved a greater global warmth (about +1°C with reference to year 2000, according to ocean cores, see Hansen & Sato above), high enough to entail a 5m higher sea level than at present, but did not provoke a self-stoking methane/CO2 release sufficient to prevent later re-glaciation. In the last very few decades, however, humanity is administering a powerful thermal shock to a still warm inter-glacial by inducing concentrations of non-condensing greenhouse gases that are higher by a margin not seen in the past 2 – 5 million or more years.

For those readers who are interested in Arctic methane and the basis for future studies, there is also in my longer article an introductory discussion of a very recent publication: “Gas Hydrate Formation and Dissipation Histories in the Northern Margin of Canada”, 2012. I have even more recently read this paper “On carbon transport and fate in the East Siberian Arctic land–shelf–atmosphere system”, 2012, which makes a strong case for future monitoring of these processes. As a ‘lay person’ I heartily endorse the authors’ case. Earlier papers by Nisbet, 2002, and Archer, 2007, are also worth reading and links are in my longer article.

5th personal insight:  atmospheric methane levels, and their impacts, depend on the rate of release not on reserves

In my longer article I comment in more detail on the calculations and thesis accompanying the ‘Kilda conjecture’ published in the journal Nature Geoscience; Nisbet, 2009 (7). Recent calculations have assessed the quantities and the rate of release that would be needed for a sustained methane-induced thermal shock to the climate, large enough to lead to a runaway effect. The present dissipation of clathrates (or other near surface organic sources of methane) to the air, is more likely to remain chronic and will probably contribute to sustaining the high man-made level of atmospheric methane, rather than, on its own, initiate runaway ‘positive feedback’. (It can be assumed that in the absence of very high sustained ‘natural’ levels, future atmospheric CH4 levels would rapidly reduce if methane release from fossil fuels was to stop.)

(7) The period between gas release events (repeat time) needs to be comparable to, or shorter than, the atmospheric residence time of the warming gas, otherwise the warming effect of one release event will fade before the next event occurs. [Emphasis added.]

The snag, though, it seems is the continuing very large man-made releases of both CH4 and CO2, particularly from remaining fossil fuels, and the raised CO2 concentrations that will continue long after most fossil fuels have been burned.

6th personal insight: requirements for a disrupted carbon cycle and sustained climate disorder can be described; for example, the Kilda conjecture

A massive climate impact, such as the start of a disordered carbon cycle of the size-order of the Paleocene/Eocene Thermal Maximum, PETM, would require a very large and sustained release of greenhouse gases.

(7) a recurrent release of greenhouse gases is therefore required to explain the much longer-term warming in the PETM. …

Even a large release from a single deep ocean clathrate deposit, perhaps if it occurred because of volcanic action unrelated to climate change, would not be enough to firstly interrupt and then promote self-sustaining disorder of the carbon cycle. I quote from my own longer article:

“In particular, single event methane releases have been examined [by Nisbet et al. (7)] as putative trigger events for a cascade leading to sustained high levels of atmospheric non-condensing gases. Single releases from sources such as ocean floor hydrates were/are not, individually, sufficiently large, nor did they recur frequently enough, to act as trigger events for subsequent self-sustaining high atmospheric concentrations, and these sources are rejected as explanations for the ‘PETM trigger’. The authors, though, identify one possible singular source of methane, the geologically brief Kilda Basin 55Ma. This basin apparently has no large modern parallel although some modern Rift Valley conditions provide qualitative parallels. The ancient Kilda Basin could have provided a single source large enough to suddenly overwhelm the atmospheric OH’ oxidising sink and thus prolong for many decades the atmospheric residence time of a massive methane release. Hence, the release could have been big enough to promote a subsequent very prolonged period of both high CO2 and CH4 concentrations. (It is possible that the Kilda Basin might have produced recurrent exhalations). Plausibly the trajectory to the inevitable PETM was begun in this way. The authors speculate:

(7) Unlike other suggested triggers, bursts of methane and carbon dioxide from Kilda could have been large enough, and could have been repeated frequently enough, to initiate the persistent global warming throughout the PETM. Could the comparable injection of modern anthropogenic emissions induce the same response from the planet? [Emphasis added.]

Remaining queries:

Thus, for now, my remaining query will be: Are ‘we’ the modern ‘Kilda Basin’?
Could ‘we’ be an initiating trigger like Kilda? There are already signs of a disrupted carbon cycle as we lower the pH in the ocean. Modern rising CO2 levels are rising more rapidly and changing the ocean more quickly than the slow changes recorded for the Pliocene a mere 5 million years ago when CO2 was last near 390ppm in the atmosphere. [See refs 8 and 9]

The configuration of the continents, mountain ranges and ocean connections are different from those 55 million years ago. The PETM took (several) thousands of years to reach a maximum. We can hope our descendants will be spared.

Personally I do not wish to even think about a future PETM equivalent, even if it is not imminent for a thousand years. The current human-induced mass extinction of biota and the emergence of a ‘New Climate’ are bad enough to contemplate, even with scientific caveats about uncertainty. There was a symposium in London at the Royal Society of Chemistry, Burlington House, November 2-3, 2010, and abstracts are available on-line (10). Presentations reviewed past Carbon Isotope Excursions, CIE’s, particularly the Palaeocene Eocene thermal maximum (PETM, 55Ma), when discussion centred on these past ‘greenhouse worlds’ and mass extinction events as analogues for future events and ecologies. I refer you to the set of symposium abstracts4 and leave you with the safety instructions for Burlington House displayed prominently at the end of the programme ’flyer’

If you hear the Alarm

Alarm Bells are situated throughout the building and will ring continuously for an evacuation. 

Do not stop to collect your personal belongings. 

 Notes and references

1. In remote geological times, carbon became sequestered in very large persistent sinks of carbonaceous rock and in petroleum and gas deposits. Weathering, tectonic movement and volcanic activity release carbon from rocks, and seepage occurs from trapped “fossil fuels” and buried organic material, but since the last 10s of millions of years, the earlier sequestration has had the net ongoing effect of a reduced carbon gas level maintained in the atmosphere. Thus, more recent geological ages have experienced much lower levels of free CO2 and CH4 than those remote epochs when the largest ancient carbon stores were laid down.
2. PETM: Palaeocene/Eocene Thermal Maximum. Configurations of continents mountain ranges and oceans have changed since then and the world now could have a different reaction to ‘trigger events’.
3. Snowball Earth termination by destabilization of equatorial permafrost methane clathrate; Kennedy M, Mrofka D, von der Borch C. Nature, 2008 May 29; 453(7195):642-5.
4.  Atmospheric CO2: principal control knob governing Earth's temperature; Lacis A.A. et al. Science. 2010 Oct 15;330 (6002):356-9.
5. Global atmospheric methane: budget, changes and dangers; Dlugokencky EJ, et al. Philos Transact A Math Phys Eng Sci. 2011 May 28; 369(1943):2058-72. 
6. Paleoclimate Implications for Human-Made Climate Change, Hansen & Sato, 2011, submitted for publication. FULL PAPER
7. Kick-starting ancient warming; E. G. Nisbet et al.; 2009, Nature Geoscience 2, 156 - 159 (2009)
8. I refer you to recent FAQs and programmes of research on ocean acidification; here.
9. The Geological Record of Ocean Acidification, Bärbel Hönisch et al, Science 2 March 2012: 335 no. 6072 pp. 1058-1063 ABSTRACT
10. Past CIEs and future ecologies; Burlington House, London, 2-3 November 2010 ABSTRACTS HERE


Thursday, April 26, 2012

Wonderful World

Take two minutes of relax to look at this clip: too beautiful to miss (h/t Tenney Naumer).

Monday, April 23, 2012

The story of Rabbit Island

This post had started as a review of the book "Too Smart for Our Own Good" by Craig Dilworth. After having worked on it for a while, however, I found that I could add nothing to the excellent review already written by George Mobus. So, I thought that I could rather express my feelings in terms of a little story. If you have studied population dynamics, you'll recognize that what I wrote is a fictionalized version of the Lotka-Volterra model of foxes and rabbits interaction. I think it is the bottom line of Dilworth's thesis: humans are smart at inventing technological toys just as foxes are smart at catching rabbits. The results, however, are not necessarily good. It doesn't matter if you are a fox or a human being: you are too smart for your own good. (Image above from Jokeroo)

The Story of Rabbit Island
by Ugo Bardi

It is said that foxes came to the Island long, long ago. Some say that the first fox couple arrived on a raft from a place beyond the horizon. Others say, instead, that foxes were created here by the Fox-God, and others still that they had always been here, from the day when the Gods raised the Island out of the waters of the infinite Ocean.

Wherever they came from, the first fox couple found the Island rich in grass, trees, water, and many, many rabbits. And the foxes were smart and strong and they grew by chasing rabbits and killing them in great numbers. Many young foxes were born and that was -  some foxes said -  the way things had to be.

In time, foxes grew even more in numbers and some foxes started saying that rabbits had become difficult to find. A story is told of an old fox, that many saw as wiser than most, who gathered the whole fox folk and spoke to them. "Fellow foxes," the old fox said, "we have been growing so much in numbers that soon there won't be enough rabbits to feed our youngsters; and they will starve. We shouldn't kill so many rabbits as we have been doing so far, and we shouldn't have such large litters, either."

But some foxes said that there was no such a thing as too much killing of rabbits. They said that there were still plenty of rabbits around; it was just a question of looking harder. If some young foxes were starving, they said, it was because they had become lazy. They had to be taught how to run faster and to be smarter. In this way, foxes would still be able to catch as many rabbits as they needed. And they laughed at the old fox and they returned to chasing rabbits.

And then, the Great Die-Off came. I have been telling this story many times and it still scares me, even though I am the oldest rabbit of the Island. But I have to tell to you this story, young rabbits. I have heard it from my father, who heard it from his father, who heard it from the father of his father, and so on in a chain that arrives to one of the few rabbits who survived the Great Die-Off. And, believe me, young rabbits, it was a terrible time, for the Island was full of foxes. Rabbits died in large numbers and there was no way for them to escape. It is said that just a few of them could hide in the darkest places of the forest; in thornbushes and in mazes of tree roots, praying the Rabbit-God that they could be spared from the fury of the foxes.

And the Rabbit-God must have heard their prayers because they were not found by the foxes. After some time, they dared to come out of their hideouts and they found that there was no fox to be seen alive anywhere on the island; only their bones were left; strewn all over the plains. Once, there were many, many more of these bones, but you may have had a chance, young rabbits, to see some of the few that remain.

So, this story has a happy ending. After the Great Die Off was over, we rabbits had the Island all for ourselves. And we have had good grass to eat and good times to grow and multiply, which some say is what the Rabbit God told us to do. Yet, sometimes I think that this story may not have such a happy ending after all.

You know that there are now many, many rabbits living in the island; so many that fields seem at times to be white and brown rather than green. And that cannot be good. Some of the wise rabbits have been telling us that we shouldn't let our numbers grow so much, because grass can't regrow fast enough to feed so many of us. But others have said that grass is not the problem. Young rabbits have become lazy, they say, and they only complain so much because they can't always find grass at paw length. That's not the way a good rabbit should be: they must learn to find their food, even at the cost of walking far away, where there is still plenty of grass.

It may be that there is still enough grass for all of us, somewhere, although I doubt it. But what makes me afraid the most is what I have been hearing lately. You may have heard the same rumors: that some rabbits have disappeared and nothing was heard of them any more - not even their bones could be found. And you may have heard of some who have been telling of grey shapes they saw hiding in the forest. And, at nightfall, some have been telling of bright, yellow eyes looking at them from the darkness. Could it be, God forbid, that the foxes are back?

If that is true, nobody can say if some foxes had survived the Great Die-Off, or if some of them came again on a raft from beyond the horizon. The only thing I can tell is that perhaps we should not have grown in numbers so much, because rabbits make good food for foxes and some old rabbit folks had alerted us about that; long ago, but nobody listened to them. And now it is too late. I am an old rabbit now, so I won't see what the future has in store; but you will, young rabbits. So, it is time for you to go to sleep. Sleep well and don't look at the forest. 

Tuesday, April 17, 2012

Getting our land back

Lorenza Zambon, actress and gardener, tells the story of a couple who decided to demolish some property of theirs and return the area to fertile soil. A few square meters gained, about one trillion still to recover.

It is not easy to determine the area of the world covered by human-made artifacts, that is by roads, houses, parkings, buildings, commercial centers and all the rest. But much work has been performed in recent times and the estimates are starting to converge on reasonable values. The results for the fraction of area covered with permanent structures range from about 0.5% (Schneider et al., 2009) to about 3% (Global Rural-Urban Mapping Project, 2004). Translated into areas, these values correspond to a minimum of 700,000 square km and to a maximum of about three million square km. To visualize these areas, think that the first one compares to France (550,000 square km) and the second to India (3.2 million square km).

No matter which result we should consider as the most reliable, the data clearly show that building takes place mostly in flat and fertile areas. There, the fractions covered by human-made structures are much larger than the world average. For instance, recent data for Europe indicate that, in January 2012, the most urbanized European states were Holland and Belgium with, respectively, 13.2% and 9.8% of the surface. As you see below (From Schneider et al.), urbanization in Europe is, indeed, concentrated in the fertile plains. Apparently, we are engaged in the task of destroying the land that supports our physical existence.

We have no data telling us how fast this paving of land has been going on up to now but, if it is proportional to the production of cement, growth has been spectacular (data from USGS).

It is impressive that the curve shows no sign of abating whatsoever. Maybe there will be a peak in the coming years, but cement is a form of "persistent pollution." Reducing its production - or even stopping it - won't automatically return built environment to fertile soil. But we can't eat concrete. Will we ever get our land back? 

Restoring to fertility land covered with concrete is an enormous task, but not an impossible one. So, Lorenza Zambon, actress and gardener, tells the story of a couple in Turin, Italy, who decided to give to their children a patch of fertile land as a gift. They obtained it by demolishing a few concrete garages they had inherited.

It was a lot of work; concrete had to be cut and broken to pieces and the rubble carried away. Then, restoring the fertility of the soil took truckloads of dirt, charcoal, and more. Zambon doesn't tell us how long the task took nor how much it cost, but surely it was slow, messy and expensive. It was also a subversive idea: in the generally accepted view, paving the land means "developing" it, and that means making money. So, destroying property to restore the fertile soil is something that nobody in his/her right mind would - normally - do.

But someone did it. The end result was a patch fertile soil where grass and flowers grow. Just a few tens of square meters, not much in comparison to the trillion remaining to be recovered. But it is a first step!

This post was inspired by a talk given by Lorenza Zambon in Florence on March 24, 2012. If you want to hear Lorenza speaking on these matters, you can find one of her presentations here, unfortunately it seems that she does that only in Italian.

Sunday, April 15, 2012

The climate conundrum

Jo Abbess summarizes very nicely the climate communication conundrum on her blog. Here is an excerpt, to which I have added an extra paragraph (image from Tumeke)

By Jo Abbess

The Evangelist : “Climate change is so serious, we need to tell everybody about it. Everybody needs to wake up about it.” The Audience “We have heard this all before. Do pipe down.”

The Social Engineer : “Everybody should be playing their part in acting on climate change.” The Audience : “This story is too heavy – you’re trying to make us feel guilty. You’re damaging your message by accusing people of being responsible for causing climate change.”

The Social Psychologist : “By making such a big deal out of climate change, by using Apocalyptic language, audiences feel there is no hope.” The Audience : “Climate change is clearly not a big deal, otherwise the newspapers and TV would be full of it all the time.”

The Post-Economist : “Climate change is caused by consumption. We need to reduce our consumption.” The Audience : “We don’t want to be told to live in cold caves, eating raw vegetables by candlelight, thanks.”

The Defeatist : “It’s already too late. There’s nothing we can do about it. All I can do is sit back and watch it happen.” The Audience : “Isn’t that being a little too negative ? If you think there’s nothing that can be done, what hope have we got ?”

The Scientist (extra paragraph by Ugo Bardi): "We have clear proof that climate change is occurring and that it will cause immense damage if we don't do something to stop it."  The Audience: "We like you scientists when you bring us solutions. We hate you when you bring us problems."

Read the rest of Jo Abbess's post here.

Saturday, April 14, 2012

Interview with professor Will Verstraete on "The Limits to Growth"

Lou Del Bello, who keeps the blog of ASPO-Italy, interviews professor Will Verstraete of Gent University, Belgium. Recorded at the Environmental Microbiology and Biotechnology meeting held in Bologna, Italy, on April 10-12 2012 (subtitles also in Italian - courtesy of Massimiliano Rupalti)

Tuesday, April 10, 2012

The Return of The Limits to Growth

40 years after, "The Limits to Growth" is back in the news. Sooner or later, someone had to notice that the economic crisis that we are seeing all around us is something that eerily reminds the "base case" scenario of the old Limits study of 1972. Someone did, eventually. Here is a comment of mine on the event.

From "Financialsense"

Public Awakens to Limits of Growth

Recently, the web has been abuzz over an MIT study predicting 'global economic collapse' by 2030. Ugo Bardi, who recently published the book The Limits to Growth Revisited, shares his views on this study and its implications.
limits to growthThis year, we have reached the 40th anniversary of the controversial study, "The Limits to Growth," originally conducted in 1972. It was sponsored by the think-tank called the "Club of Rome" and performed by a group of researchers at MIT, led by Dennis Meadows, using the most powerful computers of the time. Using data going back hundreds of years they created a long term model of major global trends taking into account resource depletion, birth and death rates, population growth, pollution, and food per capita (see image).

It was a bold attempt using innovative methods that showed the economic growth experienced up to that time would be impossible to maintain beyond the first few decades of the 20th century. It was not a prophecy of doom, but a warning that included ways and methods to avoid the decline indicated by the calculations. But it was not understood. After a moment of intense interest that lasted a few years and led the study to become well known with the general public, there came a strong negative reaction. In the 1980s and 1990s, the study was attacked, demonized, and ridiculed in all possible ways. With the apparent end of the oil crisis, in the late 1980s, the ensuing general wave of optimism consigned the Limits study to the dustbin of "wrong" scientific ideas; together with the dinosaurs of Venus and the evolution of the giraffes' necks according to Lamarck. Urban legends on the "mistakes" of the Limits study are still common today, despite being just that: legends.

But, with the turn of the century, the general attitude seems to be changing. In 2004, some of the authors of the original "Limits" published "Limits to Growth; The 30-Year Update", confirming the result of the earlier, 1972 study. In 2011, Ugo Bardi published "
The Limits to Growth Revisited" (Springer ed.) which reviewed the whole story of the study, from its inception, the demonization and the new trend of reappraisal. In 2008, the Australian physicist Graham Turner1 had compared real world data to the "base case" scenario of the orginal 1972 study, finding a good agreement; an impressive result taking into account that the scenario spanned more than three decades! These are just examples of a return of interest in the old Limits which is now perceived as more and more relevant to us, especially in view of the ongoing economic crisis.

Today, with the 40th anniversary of the first book, the return of interest in the Limits seems to be literally exploding. On March 16, 2012, the Smithsonian magazine published a comment, citing Turner's work.
2 The Smithsonian piece has been taken up on April 4 by Eric Pfeiffer on Yahoo news3, which seems to be the first appearance of the study in mainstream news in the 21st century (by April 5, it had more than 13,000 comments!). Unfortunately, Pfeiffer's piece is full of imprecisions and mistakes. Among these, Pfeiffer states that "This post has been edited to reflect that MIT has not updated its research from the original 1972 study," which is not true: the study was updated two times, in 1992 and in 2004. Then Pfeiffer  says that "the study said 'unlimited economic growth' is still possible if world governments enact policies and invest in green technologies that help limit the expansion of our ecological footprint," while the study said exactly the opposite: that unlimited economic growth is impossible, but that green technologies and other forms of policy could at most avoid the collapse.

Pfeiffer's text shows how difficult it is, still today, to understand the Limits study. Nevertheless, it is an important milestone of the public's realization that certain trends taking place are unsustainable. The renewed diffusion of the study might lead to reconsider the ideas proposed as ways to avoid collapse in the 1972 study (and reiterated in the later editions). We lost 40 years that could have been used to prepare for what we are seeing happening today in the world's economy but, perhaps, it is not too late to do something to reduce the impact of the crisis. The future can never be exactly predicted, but we can be prepared for it and the old Limits study, and its later versions, can greatly help us at that. 

1 Graham Turner (2008). "A Comparison of `The Limits to Growth` with Thirty Years of Reality". Commonwealth Scientific and Industrial Research Organisation (CSIRO).

Thursday, April 5, 2012

Peak eggs: Hubbert and the Easter Bunny

Here is a little Easter post where I try to model the Easter Egg hunt as if it were the production of a mineral resource. A simple model based on system dynamics turns out to be equivalent to the Hubbert model of oil production. We can have "peak eggs" and the curve may also take the asymmetric shape of the "Seneca Peak." So, even this simple model confirms what the Roman Philosopher told us long ago: that ruin is much faster than fortune. (Image from uptownupdate)

For those of you who may not be familiar with the Easter Bunny tradition, let me say that, in the US, bunnies lay eggs and not just that: for Easter, they lay brightly colored eggs. Tradition is that the Easter Bunny spreads a number of these eggs in the garden and then it is up to children to find them. It is a game that children usually love and that can last quite some time if the garden is big and the bunny has been a little mean in hiding the eggs in difficult places.

A curious facet of the Easter Egg hunt is that it looks a little like mineral prospecting. With minerals, just as for eggs, you need to search for hidden treasures and, once you have discovered the easy minerals (or eggs), finding the well hidden ones may take a lot of work. So much that some eggs usually remain undiscovered; just as some minerals will never be extracted.

Now, if searching for minerals is similar to searching for Easter Eggs, perhaps we could learn something very general if we try a little exercise in model building. We can use system dynamics to make a model that turns out to be able to describe both the Easter Eggs search and the common "Hubbert" behavior of mineral production. The exercise can also tell us something on how system dynamics can be used to make "mind sized" models (to use an expression coined by Seymour Papert). So, let's try.

System dynamics models are based on "stocks"; that is amounts of the things you are interested in (in this case, eggs). Stocks will not stay fixed (otherwise it would be a very uninteresting model) but will change with time. We say that stocks (eggs) "flow" from one to another. In this case, eggs start all in the stock that we call "hidden eggs" and flow into the stock that we call "found eggs". Then, we also need to consider another stock: the number of children engaged in the search.

To make a model, we need to make some assumptions. We could say that the number of eggs found per unit time is proportional to the number of children, which we might take as constant. Then, we could also say that it becomes more difficult to find eggs as there are less of them left. That's about all we need for a very basic version of the model.

Those are all conditions that we could write in the form of equations, but here we can use a well known method in system dynamics which builds the equations starting from a graphical version of the model. Traditionally, stocks are shown as boxes and flows as double edged arrows. Single edged arrows relate stocks and flows to each other. In this case, I used a program called "Vensim" by Ventana systems (free for personal and academic use). So, here is the simplest possible version of the Easter Egg Hunt model:

As you see, there are three "boxes," all labeled with what they contain. The two-sided arrow shows how the same kind of stock (eggs) flows from one box to the other. The little butterfly-like thing is the "valve" that regulates the flow. Production depends on three parameters: 1) the ability of the children to find eggs, 2) the number of children (here taken as constant) and 3) the number of remaining hidden eggs.

The model produces an output that depends on the values of the parameters. Below, there are the results for the production flow for a run that has 50 starting eggs, 10 children and an ability parameter of 0.006. Note that the number of eggs is assumed to be a continuous function. There are other methods of modeling that assume discrete numbers, but this is the way that system dynamics works.

Here, production goes down to nearly zero, as the children deplete their egg reservoir. In this version of the model, we have robot-children who continue searching forever and, eventually, they'll always find all the eggs. In practice, at some moment real children will stop searching when they become tired. But this model may still be an approximate description of an actual egg hunt when there is a fixed number of children - as it is often the case when the number of children is small.

But can we make a more general model? Suppose that there are many children and that not all of them get tired at the same time. We may assume that they drop out of the hunt simply at random. Then, can we assume that the game becomes so interesting that more children will be drawn in as more eggs are found? That, too can be simulated. A simple way of doing it is to assume that the number of children joining the search is proportional to the number of eggs found (egg production). Here is a model with these assumptions. (note the little clouds: they mean that we don't care about the size of the stocks where the children go or come from)

This model is a little more complex but not so much. Note that there are two new constants "k1" and "k2" used to "tune" the sensitivity of the children stock to the rest of the model. The results for egg production are the following:

Now egg production shows a very nice, bell shaped peak. This shape is a robust feature of the model. You can play with the constants as you like, but what you get, normally, is this kind of symmetric peak. As you probably know, this is the basic characteristic of the Hubbert model of oil production, where the peak is normally called "Hubbert  peak". Actually, this simple egg hunt model is equivalent to the one that I used, together with my coworker Alessandro Lavacchi, to describe real historical cases of the production of non renewable resources. (see this article published in "Energies" and here for a summary)

We can play a little more with the model. How about supposing that the children can learn how to find eggs faster, as the search goes on? That can be simulated by assuming that the "ability" parameter increases with time. We could say that it ramps up of a notch for every egg found. The results? Well, here is an example:

We still have a peak, but now it has become asymmetric. It is not any more the Hubbert peak but something that I have termed the "Seneca peak" from the words of the Roman philosopher Seneca who noted that ruin is usually much faster than fortune. In this example, ruin comes so fast precisely because people try to do their best to avoid it! It is a classic case of "pulling the levers in the wrong direction", as Donella Meadows told us some time ago. It is counter-intuitive but, when exploiting a non renewable resource, becoming more efficient is not a good idea.

There are many ways to skin a rabbit, so to say. So, this model can be modified in many ways, but let's stop here. I think this is a good illustration of how to play with "mind sized" models based on system dynamics and how even very simple models may give us some hint of how the real world works. This said, happy Easter, everyone!

(BTW, the model shown here is rather abstract and not thought to describe an actual Easter Egg hunt. But, who knows? It would be nice to compare the results of the model with some real world data. My children are grown-ups by now, but maybe someone would be able to collect actual data this Easter!)

Sunday, April 1, 2012

Breakthrough in free energy: the B-Cat

Today, in a press release, prof. Ugo Bardi has disclosed the development of a new Free Energy device that he stated will solve all the energy problems of the world. The device, termed "B-Cat" (schematically shown above*) generates at no cost continuous and never ending oscillations that can be tapped to produce energy.
Prof Bardi did not disclose the details of the mechanism that makes the B-Cat work, hinting, however, that it is proof of a "new physics" that goes beyond the dusty, so called "laws of thermodynamics."  Such old concepts must now be abandoned in the face of this new evidence; in spite of the stiff opposition by the fossil fuels lobby, the renewables lobby, the Gnomes of Zurich and the Old Man of the Mountain. 

Professor Bardi said that the term "B-Cat" refers to a special nuclear catalyst located inside the hat-like object on top of the oscillating bar (and, no, not to the word "bird"). This catalyst creates a cold fusion reaction between hydrogen generated by the liquid located at the basis of the bar (whose composition has not been disclosed) and green kryptonite located inside the hat-like object. The rim of the hat is in lead and it completely screens the gamma rays emitted by the device, making it completely safe for home applications, such as salami slicing or self powered swinging chairs.

Bardi reports that NASA, Siemens, General Motors and the National Rifle Association have all expressed interest in performing research and development on the B-Cat. Patent applications have been filed with the Transylvania patent office and certifications of safe use and radiation shielding are being obtained by Elfin Laboratories inc. Bardi has also specified that a robotized factory that can produce one million B-Cats per year is being assembled in an undisclosed location above the Arctic Circle. 

The present B-Cat has a power of 1 kW. Further research on improving the device is in progress in collaboration with the university of Duckburg and a 1 MW B-Cat has been developed. The prototype is shown in this movie

* the drawing of the "drinking bird" is from the site of the California State University in Fresno, which is completely, definitely and absolutely not involved with anything mentioned in this 1st of April post. If you are missing the point of this story (but, in this case, you must have just returned from a desert island where you have been marooned for more than one year), you can read this post by Steven Krivit about Andrea Rossi's E-Cat or one of my previous posts on this subject, here, and here.


Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)