book review: On The Origin of Species by Charles Darwin

Charles Darwin wrote this most famous book in 1859 so I had modest expectations given how much we have since learned about evolution and genetics.

I was pleasantly surprised to find that the book has stood the test of time very well.

Darwin had an excellent mind and writing skills. Highly recommended.

After completing this book I recommend you read Varki’s book where he builds on Darwin’s theory to explain the singular emergence of an intelligent species with an extended theory of mind, and some of our constructive and destructive behaviors.

book review: Our Renewable Future by Richard Heinberg and David Fridley

A new book titled Our Renewable Future by Richard Heinberg and David Fridley is available to read online for free here.

The book is an excellent primer on energy and does a nice job of summarizing the challenges we face as fossil energy depletes.

Heinberg’s style is to present an intelligent fact-based view of the challenges while simultaneously offering positive things we could choose to do to make the future less bad. He avoids predicting pain or collapse although having followed him for years I think this is likely a politically correct veneer. He also tends to ignore the effect of de-growth on our debt-based economy and the resulting small amount of wealth we will have available for investment.

I like the fact that the book uses a wide lens and discusses things often ignored like high temperature industrial processes that cannot run on renewable energy (concrete, metal, and silicon chip production, for example) and discusses the use of fossil energy as feedstocks (fertilizer needed to feed 7 billion, for example). I also like that it discusses honestly the need to reduce our population.

If you’d like a calm intelligent summary of our predicament with lots of space to draw your own conclusions this book a great place to start.

As an aside, I remember David Fridley from an excellent talk he gave in 2007 on the Myths of Biofuels. It’s still relevant and worth watching here.

book review: A Full Life: Reflections at Ninety by Jimmy Carter

Jimmy Carter has long been one of the few world leaders that I respect.

I just finished his latest book which provides a summary of his life and core beliefs.

Jimmy Carter really did have a full life. The breadth of his experience and accomplishments are remarkable and inspirational. He was a farmer, business man, nuclear submariner, wise president, peace envoy, humanitarian, and community leader.

Carter grew up in the depression where he learned the importance of hard work, self-sufficiency, frugality, honesty, and community. These values guided the remainder of his life, including his one term as US president.

I’ve listened many times to Carter’s 1979 speech in which he explains the reality of finite fossil energy and what citizens and government should do in response. It’s by far the best wisdom and policy I’ve ever heard from a leader.

The citizens rejected Carter’s tonic for Reagan’s morning in America. For me this is the saddest point in democratic history.

Carter advocated conservation, austerity, and living within the constraints of non-renewable resources. Instead we chose to use debt to mask reality and to climb a cliff that will be very difficult to safely climb down from.

I read the book primarily because I was hoping to hear his latest insights on energy, environment, and the economy now that 40 years have passed since his presidency. I was disappointed that he said nothing on the topic, nor did he elaborate on his energy position of the 70’s. Most other topics were covered in quite a bit of detail so I found this omission odd. He didn’t hesitate from saying “I told you so” on many other topics. It makes me wonder.

Perhaps Carter’s understanding of thermodynamics and the relationship between energy, environment, and wealth is less than I had hoped. Perhaps his understanding is limited to lessons learned from having to live within meager means during the depression. Perhaps he is afraid to speak about our current situation. I don’t know.

Setting my energy disappointment aside, and turning a blind eye to his religious beliefs, I very much enjoyed the book and recommend it.

Jimmy Carter was and is a great man who lived an inspirational life.

book review: The Vital Question: Energy, Evolution, and the Origins of Complex Life by Nick Lane

Nick Lane has long been one of my favorite science writers, setting aside Varki of course who will always have a special place in my heart.

Nick Lane’s last book Life Ascending: The Ten Great Inventions of Evolution” discussed the 10 most important inventions of evolution: the origin of life, DNA, photosynthesis, the complex cell, sex, movement, sight, hot blood, consciousness, and death. I read the book 4 times, was enthralled each time, and no doubt will read it again.

An earlier book by Nick Lane, “Oxygen: The Molecule that Made the World” discussed the amazing transformation of our planet by photosynthesis. After reading this book I look at grass with different eyes. And I love to tell the story of oxygen to any soul who will listen.

In his latest book “The Vital Question: Energy, Evolution, and the Origins of Complex Life” Lane has outdone himself.

The book is sweeping in scope, tackles the most cosmic question, as well as some important earthly questions, is beautifully written, and reads like a page turning mystery thriller.

There is so much here, where to begin?

Lane presents the latest science on the origin of life and makes a compelling case that prokaryotic (simple single cell) life is probably common throughout the universe because all that is required is rock, water, CO2 and energy, all of which are found within alkaline hydrothermal vents on geologically active planets, of which there are 40 billion in our galaxy alone, and probably a similar number in each of the other 100 billion galaxies.

Life emerges as a gradual and predictable transition from geochemistry to biochemistry. Life is not some spiritual mystery, but rather a predictable outcome of the fact that the universe abhors an energy gradient, and life is its best mechanism for degrading energy.

This theory elegantly explains why LUCA (the Last Universal Common Ancestor of all life) and all life that followed is chemiosmotic meaning that it powers itself with a strange highly unintuitive mechanism that pumps protons across a membrane.

The human body, for example, pumps a staggering 10 to the 21st power protons per second of life.

If life is nothing but an electron looking for a place to rest, death is nothing but that electron come to rest.

Lane then turns his attention to the origin of complex life: the eukaryotic cell. All of the multicellular life on earth that normally interests us such as plants, animals, fungi, and hot girls or guys, have a common eukaryote ancestor, and it appears this ancestor emerged only once on earth about 2 billion years after the emergence of simple life. Lane considers this the black hole of biology. A vital but rarely acknowledged singularity that requires explanation.

Lane presents a theory to explain the emergence of the eukaryote and shows that unlike simple life which is probable and predictable, complex life is improbable and unpredictable. It depended on a rare endosymbiosis (merging) of prokaryotes (simple cells) somewhat analogous to a freak accident. The resulting LECA (Last Eukaryotic Common Ancestor), having 2 genomes that needed to cooperate and evolve in harmony, was probably fragile, sickly, and vulnerable to extinction which forced it to evolve many unusual characteristics common to complex life such as the nucleus, sex, two sexes, programmed cell death, germline-soma distinction, and trade-offs between fitness and fertility, adaptability and disease, and ageing and death.

As the endosymbiont (cell within the cell) evolved into mitochondria (the energy powerhouses), eukaryotes were able to break through the energy per gene barrier that constrained the morphological complexity of bacteria and archaea for 2 billion years. Suddenly there was enough energy to power the evolution of complex structure, multi-cellular life, nail salons, and the iPhone.

How lucky that our minds, the most improbable biological machines in the universe, are now a conduit for this restless flow of energy, that we can think about why life is the way it is.

This theory will be particularly satisfying to students of human overshoot who understand that abundant non-renewable energy is the main reason for the size and complexity of today’s human civilization.

The universe, life, and complexity are all about energy.

I am a fan and student of Varki’s theory that human success is the result of a rare simultaneous mutation for denial of reality and an extended theory of mind.

Combining Nick Lane’s theory with Ajit Varki’s theory, and an understanding of our place on the overshoot curve, leads one to an amazing and almost mystical conclusion.

Intelligent life with an extended theory of mind is the result of a rare and unpredictable double mutation, layered on the emergence of complex cells, another rare and unpredictable accident. Intelligent life in the universe is therefore rare and will probably exist for only a short time before its intelligence fueled overshoot, and denial thereof, causes it to go extinct.

The fact that we are alive to witness and understand a very rare peak of intelligent life in the universe is cause for genuine awe.

We should savor it while it lasts.

Here is Nick Lane talking about some of the ideas in his book. I much preferred the book because the subject is too deep to be covered in a 30 minute talk but it’s a taste if you don’t have time for the full meal.

Here is an excerpt from the book’s epilogue.

All life on earth is chemiosmotic, depending on proton gradients across membranes to drive carbon and energy metabolism. We have explored the possible origins and consequences of this peculiar trait. We’ve seen that living requires a continuous driving force, an unceasing chemical reaction that produces reactive intermediates, including molecules like ATP, as by-products. Such molecules drive the energy-demanding reactions that make up cells. This flux of carbon and energy must have been even greater at the origins of life, before the evolution of biological catalysts, which constrained the flow of metabolism within narrow channels. Very few natural environments meet the requirements for life – a continuous, high flux of carbon and usable energy across mineral catalysts, constrained in a naturally microcompartmentalised system, capable of concentrating products and venting waste. While there may be other environments that meet these criteria, alkaline hydrothermal vents most certainly do, and such vents are likely to be common on wet rocky planets across the universe. The shopping list for life in these vents is just rock (olivine), water and CO2, three of the most ubiquitous substances in the universe. Suitable conditions for the origin of life might be present, right now, on some 40 billion planets in the Milky Way alone.

Alkaline hydrothermal vents come with both a problem and a solution: they are rich in H2, but this gas does not react readily with CO2. We have seen that natural proton gradients across thin semiconducting mineral barriers could theoretically drive the formation of organics, and ultimately the emergence of cells, within the pores of the vents. If so, life depended from the very beginning on proton gradients (and iron–sulphur minerals) to break down the kinetic barriers to the reaction of H2 and CO2. To grow on natural proton gradients, these early cells required leaky membranes, capable of retaining the molecules needed for life without cutting themselves off from the energising flux of protons. That, in turn, precluded their escape from the vents, except through the strait gates of a strict succession of events (requiring an antiporter), which enabled the coevolution of active ion pumps and modern phospholipid membranes. Only then could cells leave the vents, and colonise the oceans and rocks of the early earth. We saw that this strict succession of events could explain the paradoxical properties of LUCA, the last universal common ancestor of life, as well as the deep divergence of bacteria and archaea. Not least, these strict requirements can explain why all life on earth is chemiosmotic – why this strange trait is as universal as the genetic code itself.

This scenario – an environment that is common in cosmic terms, but with a strict set of constraints governing outcomes – makes it likely that life elsewhere in the universe will also be chemiosmotic, and so will face parallel opportunities and constraints. Chemiosmotic coupling gives life unlimited metabolic versatility, allowing cells to ‘eat’ and ‘breathe’ practically anything. Just as genes can be passed around by lateral gene transfer, because the genetic code is universal, so too the toolkit for metabolic adaptation to very diverse environments can be passed around, as all cells use a common operating system. I would be amazed if we did not find bacteria right across the universe, including our own solar system, all working in much the same way, powered by redox chemistry and proton gradients across membranes. It’s predictable from first principles.

But if that’s true, then complex life elsewhere in the universe will face exactly the same constraints as eukaryotes on earth – aliens should have mitochondria too. We’ve seen that all eukaryotes share a common ancestor which arose just once, through a rare endosymbiosis between prokaryotes. We know of two such endosymbioses between bacteria (Figure 25) – three, if we include Parakaryon myojinensis – so we know that it is possible for bacteria to get inside bacteria without phagocytosis. Presumably there must have been thousands, perhaps millions, of cases over 4 billion years of evolution. It’s a bottleneck, but not a stringent one. In each case, we would expect to see gene loss from the endosymbionts, and a tendency to greater size and genomic complexity in the host cell – exactly what we do see in Parakaryon myojinensis. But we’d also expect intimate conflict between the host and the endosymbiont – this is the second part of the bottleneck, a double whammy that makes the evolution of complex life genuinely difficult. We saw that the first eukaryotes most likely evolved quickly in small populations; the very fact that the common ancestor of eukaryotes shares so many traits, none of which are found in bacteria, implies a small, unstable, sexual population. If Parakaryon myojinensis is recapitulating eukaryotic evolution, as I suspect, its extremely low population density (just one specimen in 15 years of hunting) is predictable. Its most likely fate is extinction. Perhaps it will die because it has not successfully excluded all its ribosomes from its nuclear compartment, or because it has not yet ‘invented’ sex. Or perhaps, chance in a million, it will succeed, and seed a second coming of eukaryotes on earth.

I think we can reasonably conclude that complex life will be rare in the universe – there is no innate tendency in natural selection to give rise to humans or any other form of complex life. It is far more likely to get stuck at the bacterial level of complexity. I can’t put a statistical probability on that. The existence of Parakaryon myojinensis might be encouraging for some – multiple origins of complexity on earth means that complex life might be more common elsewhere in the universe. Maybe. What I would argue with more certainty is that, for energetic reasons, the evolution of complex life requires an endosymbiosis between two prokaryotes, and that is a rare random event, disturbingly close to a freak accident, made all the more difficult by the ensuing intimate conflict between cells. After that, we are back to standard natural selection. We’ve seen that many properties shared by eukaryotes, from the nucleus to sex, are predictable from first principles. We can go much further. The evolution of two sexes, the germline–soma distinction, programmed cell death, mosaic mitochondria, and the trade-offs between aerobic fitness and fertility, adaptability and disease, ageing and death, all these traits emerge, predictably, from the starting point that is a cell within a cell. Would it all happen over again? I think that much of it would. Incorporating energy into evolution is long overdue, and begins to lay a more predictive basis to natural selection.

Energy is far less forgiving than genes. Look around you. This wonderful world reflects the power of mutations and recombination, genetic change – the basis for natural selection. You share some of your genes with the tree through the window, but you and that tree parted company very early in eukaryotic evolution, 1.5 billion years ago, each following a different course permitted by different genes, the product of mutations, recombination, and natural selection. You run around, and I hope still climb trees occasionally; they bend gently in the breeze and convert the air into more trees, the magic trick to end them all. All of those differences are written in the genes, genes that derive from your common ancestor but have now mostly diverged beyond recognition. All those changes were permitted, selected, in the long course of evolution. Genes are almost infinitely permissive: anything that can happen will happen.

But that tree has mitochondria too, which work in much the same way as its chloroplasts, endlessly transferring electrons down its trillions upon trillions of respiratory chains, pumping protons across membranes as they always did. As you always did. These same shuttling electrons and protons have sustained you from the womb: you pump 1021 protons per second, every second, without pause. Your mitochondria were passed on from your mother, in her egg cell, her most precious gift, the gift of living that goes back unbroken, unceasing, generation on generation, to the first stirrings of life in hydrothermal vents, 4 billion years ago. Tamper with this reaction at your peril. Cyanide will stem the flow of electrons and protons, and bring your life to an abrupt end. Ageing will do the same, but slowly, gently. Death is the ceasing of electron and proton flux, the settling of membrane potential, the end of that unbroken flame. If life is nothing but an electron looking for a place to rest, death is nothing but that electron come to rest.

This energy flux is astonishing and unforgiving. Any change over seconds or minutes could bring the whole experiment to an end. Spores can pull it off, descending into metabolic dormancy from which they must feel lucky to emerge. But for the rest of us … we are sustained by the same processes that powered the first living cells. These processes have never changed in a fundamental way; how could they? Life is for the living. Living needs an unceasing flux of energy. It’s hardly surprising that energy flux puts major constraints on the path of evolution, defining what is possible. It’s not surprising that bacteria keep doing what bacteria do, unable to tinker in any serious way with the flame that keeps them growing, dividing, conquering. It’s not surprising that the one accident that did work out, that singular endosymbiosis between prokaryotes, did not tinker with the flame, but ignited it in many copies in each and every eukaryotic cell, finally giving rise to all complex life. It’s not surprising that keeping this flame alive is vital to our physiology and evolution, explaining many quirks of our past and our lives today. How lucky that our minds, the most improbable biological machines in the universe, are now a conduit for this restless flow of energy, that we can think about why life is the way it is. May the proton-motive force be with you!

By Ray Grigg: The Evolution of Denial

Ray Grigg writes an environmental column in my local newspaper and lives on an island near my home.

We’ve never met but he’s written the best review of Ajit Varki and Danny Brower’s book on denial that I have seen anywhere.

Consciousness can be costly. Philosophers and poets have long pondered this dilemma. But the idea has rarely entered the theories of evolutionary scientists until Dr. Danny Brower introduced it to Dr. Ajit Varki, an oncologist who is also an authority on cellular biology and an expert on anthropogeny (the origin of humans).Dr. Varki met Dr. Danny Brower for a brief but intense hour at a 2005 conference on the origins of human uniqueness. As a geneticist, Dr. Brower was fascinated with the evolution of human consciousness. But he was less curious about the human ability to be aware of their own minds and the minds of others as he was about the apparent inability of other animals to develop the same facility. Whales, elephants, apes, dolphins, and some birds such as magpies provide clear evidence of self-awareness. Even though they have existed in evolutionary history for much longer than humans, however, they have never developed the same degree of self-awareness, empathetic sensitivity, social sophistication and intellectual acumen as humans. Dr. Brower thought he had an answer.

His answer haunted Dr. Varki. So, when Dr. Brower died suddenly in 2007, leaving an incomplete manuscript, Denial: Self-Deception, False Beliefs, and the Origins of the Human Mind, Dr. Varki inherited the task of finishing it. The completed book explores the advantages, costs and implications of our human capacity to understand, empathize, organize and act, the attributes that define us as individuals, societies and civilizations.

Dr. Varki notes that some species of animals seem capable of recognizing themselves as individuals and of mourning the death of their fellows. Such animals may even recognize their own mortality, a traumatizing experience that could be psychologically crippling without the protection of an appropriate defence mechanism. And this mechanism, the theory proposes, is denial.

Humans may have succeeded where other species have failed because we have simultaneously developed the contradictory capacity for both self-awareness and denial. Thus we are capable of exercising all the intellectual, empathetic, social and cultural skills that are responsible for our amazing accomplishments but we are also capable of isolating ourselves from the inevitable death which shadows all our efforts. This capacity, the theory suggests, is the adroit device of evolution that allows us to function while avoiding the heavy psychological cost of knowing the inevitable consequence of being alive. The problem presented by self-awareness is solved simply by sidestepping the reality we do not want to confront.

As Dr. Varki outlines in his elaboration of Dr. Brower’s theory, this is a useful strategy for the individual. And it has advantages for society, too. So people undertake enterprises they would never begin if they actually confronted the reality of the challenges. Denial forms a partnership with optimism to remove the obstacles preventing us from attempting the unpredictable, difficult or impossible. Travelling to the moon, rowing across the Pacific, or working faithfully for 45 years to reach a retirement pension all require an erasing of very credible risks and obstacles. Such ordinary activities as having a baby, driving on a freeway, flying in an airplane or buying a lottery ticket all require acts of denial. Even falling in love is an act that doesn’t consider the possibility of heartbreak. So risk and failure are blindly overlooked for the prospect of benefit. Bravery could be one word to describe such behaviour — if we were fully aware. But a better word might be denial, a strategy which Dr. Varki refers to as “terror management”.

The shortcoming of denial, however, is that it tends to be indiscriminate — so we deny things we should confront. Denial is also a much better coping strategy for an individual than for a species. Indeed, the loss of a few individuals because of their refusal to confront reality is unlikely to endanger the viability of an entire society. But this constraint no longer applies in a globalized world. If denial is responsible for a nuclear holocaust, then this lurking Armageddon could obliterate much of civilization as we know it. What if denial results in the use of uncontrollable biological weapons, or the release of a virus which could initiate an unstoppable global pandemic? What if genetic tinkering inadvertently creates an organism which crashes the planet’s biological systems? The denial mechanism which once affected only local people in local places could potentially affect life on the entire planet.

This is the context in which Dr. Varki raises the subject of climate change. The mechanisms we use to avoid confronting this threat are extraordinary. It is a silence that pervades many conversation. It is a subject that elections commonly avoid. It is a science that politicians suppress — at least in Canada where those who raise it are deemed pessimists, heretics, cynics, enemies, radicals.

Of course, reality is remarkably insistent. So the trauma of extreme weather events force climate change into public awareness where it is too often heard but denied. The required remedial action is invariably postponed. The necessary government regulations become promises that never materialize. Excuses and rationalizations abound as the carbon dioxide levels rise and the planet’s weather becomes more unusual, threatening and destructive. Dr. Varki summarizes the stakes succinctly. “This is the one case,” he says of global warming, “where we cannot afford to get it wrong the first time.”

Dr. Varki concedes that his refinements to Dr. Brower’s theory need more scientific study and evaluation. But, he contends, the theory seems to fit the evidence. More sobering, however, is the way the theory seems to fit our history.

book review: The Alchemy of Air by Thomas Hager

The Alchemy of Air is one of the better books I’ve read.

As an engineer I’ve always been interested in the history of important science and there is nothing more important than the Haber-Bosch process which uses fossil energy to produce inexpensive fertilizer that enabled the green revolution and human overshoot.

Lest you doubt its significance, 50% of the nitrogen in our bodies was manufactured in a Haber-Bosch factory, and it is the primary reason our population grew from 1 billion to 7 billion over the last 100 years.

In addition, our liberal use of manufactured fertilizer has distorted the nitrogen cycle creating dead zones in the ocean, and contributed to pollution that is causing the decline of trees worldwide.

The Haber-Bosch process also produces the raw materials necessary for explosives and was a major contributor to the lethality of World Wars I and II.

Haber-Bosch technology was adapted to produce gasoline from coal which powered the Nazi war machine, and someday will probably power industrial civilization’s last gasp when real oil becomes too expensive to extract.

There’s a lot more in the book that I enjoyed.

The detailed history of fertilizer and the wars over its scarce non-renewable resources prior to Haber-Bosch was fascinating.

The behind the scenes look at the role of technology and big business in WWI and WWII was very interesting.

The story of how great minds were destroyed by a scapegoat seeking Hitler provides insight into what we’ll likely see in the future.

Lastly, I found the human side interesting in that men who accomplished much and earned great wealth were still unhappy and unsure of themselves.

I’ll be reading it a second time. Highly recommended.

Yuval Harari’s Sapiens

I thought I found some support for Varki’s denial theory in a new book by Yuval Harari titled Sapiens.

Harari makes the case that humans dominate the planet because we cooperate and we cooperate because we are uniquely able to construct and believe fictional stories.

This is no doubt part of the story but misses the bigger picture and lacks a satisfying explanation for why.

We dominate for many reasons. Cooperation yes, but also sophisticated symbolic language, ability to manage many relationships, forward planning, analytic skills, long term memory, learning ability, etc. All of these things fall under the umbrella of CPU power.

The important question to be answered is, why did only one small group of one species in Africa evolve this higher CPU power, despite many similar species being exposed to the same selection pressures?

Varki provides a plausible answer. Harari does not.

And of course, why with this exceptional CPU power do we believe in wacky economic theories and even wackier religions but not climate change or peak oil or almost anything that matters?

Again, Varki provides an answer. Harari does not.

Here is an EconTalk interview with Harari:

Yuval Harari on Sapiens

Here is Harari’s TED talk titled Bananas in Heaven.

book review: Storms of My Grandchildren by James Hansen

This is a review of James Hansen’s 2009 book “Storms of My Grandchildren”. James Hansen is the most respected climate scientist in the world. He is naturally shy and avoids publicity but decided to write this, his only book, after the birth of a grandchild. He wanted his grandchild to know later in life that his grandfather had done everything he could to warn the world. I’m of the opinion that Storms of My Grandchildren is the definitive book on climate change.

The density of information in the book is very high so it won’t be possible for me to summarize all of it. Instead I will try to convey the big takeaways for me. Hansen did a remarkable job of summarizing all of the important science. This science is much more complex and nuanced than I had previously thought. I was surprised how deep our understanding is, and the stability of the foundation upon which it rests. I was under the mistaken impression that most predictions had been drawn from computer models, the accuracy of which is of course dependent on model assumptions. It turns out that most of the important predictions are drawn from studying climate change throughout the geologic history of our planet, and they know a surprising amount about past climate.

Before I discuss Hansen’s conclusions, I need to digress for a moment. Experts in the fields of energy, economy, and climate tend to have narrow fields of view. Economists generally know very little about or deny the physical realities of energy and climate. Energy experts frequently dismiss climate change or are ignorant of the science. Climate scientists frequently do not understand or include the implications of peak energy and peak debt in their forecasts. These blind spots are remarkable given the intimate inter-dependencies of energy, economy, and climate.

James Hansen is no exception. From his book I conclude that he does not understand the implications and timing of peak oil, and seems to be unaware of our monetary system mathematics that guarantee collapse in the absence of growth. Therefore it is very important to place Hansen’s climate predictions in the context of his energy and economy assumptions.

Hansen assumes the economy (and hence energy consumption) will continue at roughly its current level.  He makes a very compelling case that if we continue to burn coal, oil, and natural gas at the current rate, then global warming will make the lives of our grandchildren miserable at best, and unlivable at worst.  The most important impacts being significant sea level rise, agriculture disruption, storm damage, and species extinction.

He further asserts, with no uncertainty, that if we burn all of the remaining coal plus non-conventional oil (tar sands and oil shale) then the planet will experience runaway warming and will end up like Venus with all life extinguished.

Hansen concludes (with supporting analysis) that there is only one possible solution to maintain a planet that is hospitable (if somewhat damaged) for our grandchildren:

1) We must reduce CO2 from today’s 392 ppm to below 350 ppm, and very soon. It was refreshing to hear him acknowledge how difficult this will be. For example, every single country that signed the Kyoto protocol, which promised CO2 reductions, actually saw CO2 increases, and CO2 is still increasing today. Furthermore, even countries that signed with honest intentions and worked hard on renewable energy and conservation, like Japan, still saw CO2 go up. In case you are puzzled by this, it is exactly what one would expect given that GDP is proportional to energy consumption, and 90+% of our energy comes from burning fossil fuels.

2) To achieve 350 ppm we must stop all use of coal, plus stop non-conventional oil (tar sands & oil shale), plus implement a carbon tax, plus stop deforestation, plus control population growth. Again, it was refreshing to hear him acknowledge that we cannot stop using our remaining conventional oil because there is no alternative and because we will need it for the following step.

3) To maintain civilization as we know it, and to have any hope of public support, we must replace most of the electricity that was previously generated by coal. Again I was impressed that Hansen understands that the low power density and intermittency of solar and wind eliminates them as candidates for coal replacement. Hansen says our only choice is nuclear. But current nuclear produces too much waste and consumes too much depleting non-renewable uranium. Therefore we need a crash program to develop 4th generation nuclear and a little luck. If successful, 4th generation nuclear will burn waste from today’s reactors and will produce very little new waste.

I have studied energy in sufficient depth to know that Hansen is correct about the need to replace coal with nuclear, assuming  lifestyles as usual. More specifically, I agree with Hansen that when you hear people promote clean coal (which means carbon capture and storage) you can rest assured that this is green-wash that will never happen for a variety of solid technical and economic reasons.

It’s worth reflecting on the precariousness of our grandchildren’s situation, when the only possible solution that maintains current lifestyles and a livable planet requires a new nuclear technology that is still in the R&D phase and may not work.

But now we need to circle back and revisit his initial assumption that the economy (and hence energy consumption) will continue at roughly its current level. As you know from my analysis of energy and the economy, I am certain that we are facing a global collapse. What does this mean for Hansen’s climate prediction and prescription for avoiding a disaster for our grandchildren?

When collapse occurs we can conservatively expect half of the wealth and economic activity on the planet to be wiped out. And it’s entirely possible that the decline will be much deeper than 50% given the huge levels of debt and derivatives that need to be unwound. This means that there is no chance of us being able to afford the nuclear replacement of coal given the many trillions required for the switch. Which means we will continue to burn coal but at a reduced rate because of reduced economic activity. Will this reduced energy consumption be sufficient to save our grandchildren?

But it gets more complicated. At the end of his book Hansen summarized the key uncertainties in our understanding of climate science. One of the big uncertainties is the effect of aerosols on the earth’s energy balance. Aerosols are the particulates (soot) that are emitted from the combustion of coal and diesel and other industrial processes. Aerosols tend to mask the effect of CO2 by blocking sunlight. But unlike CO2 which remains in the atmosphere for centuries, aerosols fall out of the sky after a week or so. So when economic collapse occurs, we can expect energy production and industrial activity to dramatically drop and thus aerosol production to dramatically drop. Which means that in a very short period of time we will experience increased effect of our CO2, which means we may experience a global warming “surge”.

Climate scientists acknowledge the presence of a tipping point beyond which the climate will warm no matter what we do. Many scientists are very scared that we are close to this tipping point. Hence Hansen’s call to arms for us to get back below 350 ppm.  Will the warming surge caused by economic collapse push us past the climate’s tipping point?

So now let me try to sum this all up.

If you do not believe Hansen’s predictions and prescriptions, then you really should read his book. It is very persuasive and I think it will give you confidence that he knows what he is talking about. In fact you should read it regardless. We all need to understand this stuff given the stakes.

If you do not believe that the economy will collapse, and you believe Hansen’s science, then you know exactly what needs to be done. You should push the Canadian and Alberta governments to shut down the tar sands immediately. You should push for replacing all of our coal-fired power plants with nuclear plants. You should support a carbon tax. You should support sending aid to developing countries to discourage deforestation. And you should support government policies to control population growth.

If, on the other hand, you believe my prediction of economic collapse, then our actions are less clear. We need to ask our scientists to answer the questions: 1) How much economic activity reduction is required to get us back to below 350 ppm? 2) What are the implications of a sudden drop in aerosols? With answers to these questions we can derive any further actions required to protect our grandchildren. Hopefully nothing more will need to be done than to survive a permanent economic depression.