Category: Book reviews

Under a Green Sky

Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us about Our Future

How’s this for a writer’s motivation? “I am as scared as hell, and I am not going to be silent anymore!…Thus this book, words tumbling out powered by rage and sorrow but mostly fear, not for us but for our children – and theirs.” The book is Under a Green Sky: Global Warming, the Mass Extinctions of the Past and What They Can Tell Us About our Future, first published  in 2007 with a paperback version in 2008.  The scared as hell author is Peter D. Ward, a paleontologist and and professor of Biology and of Earth and Space Sciences at the University of Washington, Seattle.

The book certainly shows why the author has reason to be scared, but he lets us know gently, with a mixture of patient explanation and lively narrative.  He has worked at many interesting sites and he knows how to bring his visits back to life for the reader, whether gently chipping at cliffs on a heavily populated French beach or spending a week of 18-hour days in unceasing rain with a small group of colleagues on a remote Queen Charlotte Islands beach and running out of food the day before weather permitted the helicopter to return.

Mass extinctions in the past are his focus.  His work helped to confirm the 1980 hypotheses of the Alvarez team that the extinction which saw the end of the dinosaurs some 65 million years ago was catastrophic and caused by an asteroid striking the earth.

There have been other sometimes greater extinction events in the past, especially the “Great Dying” at the end of the Permian period some 250 million years ago.  Were they too the result of asteroid impact?  If it could happen once, why not other times as well? Ward explains the investigations that lead to the conclusion that only the one extinction  was the result of impact.  The rest were different.

He takes the reader carefully through the discoveries which point to the proposal that they were greenhouse extinctions, the result of complex processes which began with releases of carbon dioxide and methane (sophisticated estimates of past carbon dioxide levels show sharp increases at the time of each extinction), caused initially by volcanic activity on a large scale. This meant a warmer world which affected the ocean circulation systems and disrupted the conveyor currents. The oceans were a key factor. Bottom waters started to have warm, low-oxygen water dumped into them, ocean winds and surface currents came to a near standstill so that there was less mixing of oxygenated surface water with the deeper waters and, gradually, ever-shallower water changed from oxygenated to anoxic.  When it moved high enough for light to penetrate, green sulphur bacteria expanded in numbers and filled the low-oxygen shallows.  Accompanying them were other bacteria which produced toxic amounts of hydrogen sulphide which rose into the atmosphere.  There it broke down the ozone layer and the subsequent increase in ultraviolet radiation killed much of the green plant phytoplankton.  As the hydrogen sulphide moved up into the sky it also killed some plant and animal life and its combination with high heat increased its toxicity.

This summary conclusion is supported by a wealth of careful detail.  Like most climate history it is based on a great variety of evidence from people working in many fields of study.  Much of the work and hypothesising is quite recent, and will no doubt be put to much examination  before it can be regarded as established.  In the meantime it’s a fascinating read, fully accessible to the non-scientist. (It helps to have a chart of the geological periods alongside though if, like me, you’re a bit hazy about them.)

But the book doesn’t finish there.  Ward is all too aware that we also are living in a time of rapidly rising carbon dioxide levels – not from volcanic sources this time but from burning fossil fuels.  The question he addresses is whether the rate of increase today is on a par with the rate during those times when greenhouse extinctions occurred. He concludes that the present rise seems to eclipse any other rate of increase in the past. Oceanic acidification is an indication of this, since the natural buffering systems need time to strip the carbon dioxide out of the water. We are “hurtling towards carbon dioxide levels not seen since the Eocene epoch of 60 million years ago, which, important enough, occurred right after a greenhouse extinction.”

Would it matter if human civilisation was transported to the Eocene world?  New Caledonia everyone?  Any apparent attractions are rapidly punctured.  He instances the harshness of tropical life, the catastrophe of sea level rise, high mortality rates, widespread infectious diseases, famine and war.

If we can sharply curtail emissions in the 21st century we have a chance of getting carbon dioxide levels down to 400 ppm, even if we overshoot it briefly, and hence have some chance of limiting temperature rise to 2 degrees.  If not we are heading for an ice-free world, a change in the thermohaline conveyor belt currents and a new greenhouse extinction. “The past tells us that this is so.”

Towards the end of the book he records a memorable interview with David Battisti of the University of Washington, a notable climate scientist, one of whose lectures stimulated Ward to write this book. He asks Battisti to describe verbally the world we are headed for on our current trajectory. It’s a very different world and it’s not nice, though Battisti still hopes that under the pressures of climate change we will put into place a political structure able to implement the global regulations and incentives that might rescue us.

Ward concludes with three possible scenarios based on what he has written in his book and the “massive scientific literature” dealing with global warming and climate change.  The first is the only one I can bear to contemplate.  It’s bad enough, but the sea level will have risen by ‘only’ a metre, the conveyor belt current system will not have stopped, the ocean will stay mixed.

The political solution is out of the hands of the scientists.  But the policy makers can’t say they aren’t being warned. “This book is my scream”, Ward writes. It’s a very civilised scream, like that of many other scientists, but we must hope like hell enough politicians have ears to hear it.

The other Hot Topic

The Hot Topic: How to Tackle Global Warming and Still Keep the Lights on

A book of modest size but surprisingly wide scope, The Hot Topic: How to Tackle Global Warming and Still Keep the Lights on was co-authored last year by Sir David King, former chief scientific adviser to the UK government, and science writer and broadcaster Gabrielle Walker. It has now been published in a revised and updated paperback version. Straighforward clarity marks the writing, and combined with careful organisation of the material results in some readily understandable explanations of complex matters.  Both authors are trained scientists.

The book’s structure is simple. In three parts, it first explains the problem, then discusses the technological solutions and finally canvasses the political solutions.  The intention is to show that although global warming is probably the most serious problem that the human race has, collectively, ever faced, it is not unsolvable.

The problem.  The world is warming, more so and unequivocally in recent decades.  Carbon dioxide and its sister greenhouse gases are responsible, emitted by human activity. Already some of the effects of this heating are being felt in the natural world and in human suffering.  But there is more inescapably in the pipeline, currently delayed by the built-in lag of the ocean which takes a long time to warm up. Moreover there are climate wild cards which could dramatically escalate the scale of the problem, including the shut-down of parts of the oceans’ circulation, massive abrupt sea level rise following ice sheet slide into the ocean, melting permafrost triggering the release of massive amounts of carbon, or some as yet unsuspected danger hidden in the process. But our generation has the chance, the last chance, to avoid the worst of such scenarios.

The technological solutions. We may be able to keep the temperature rise to 2 degrees centigrade if we stay below 450 parts per million CO2 equivalent, lower than earlier estimates which were too optimistic. A rise of 2 degrees will be bad enough in its effects, but we should be spurred to action, not dismayed. The wedges strategy advanced by Socolow and Pacala is the best way to proceed. Efficiency savings are the low hanging fruit and can be achieved quickly.  In transport the right kind of biofuels can play a very useful part, public transport of various kinds can make a big difference to fuel use and hydrogen still remains a possibilty as a fuel.The usual technologies for clean power generation are discussed with some caution, including carbon capture and storage; the book remarks that enough sunlight falls on the earth to meet our energy needs 10,000 times over and in principle wind could generate five times the global electricity needs.  We have the technical wherewithal and ingenuity to achive the greenhouse reductions needed, and the time to start is now.

The political solutions are more difficult. Economics first. The economic debates over discount rates rather miss the point that the science says that action cannot be put off to some future date as some economists have argued – we have to act now.  In any case the costs are not beyond our ability to pay.  Fully global cap and trade schemes, if we learn from early mistakes, can work, though they will need additional regulatory action and government investment to keep us in the right direction. A “Green New Deal” could invigorate the global economy.

On to politics. Post-Kyoto agreement will need a global target, followed by the fiendishly difficult task of dividing the global reductions among the nations of the world. The book spends some time on how this might be done, surveying various possible approaches already on negotiating tables and concluding, perhaps surprisingly, that the choice of approach makes relatively little difference to the requirements for most countries. Carrot and stick financial mechanisms will be required to encourage nations to meet their targets and provide sanctions if they don’t.  The agreement finally will need a mechanism to transfer both technology and funds from the richest countries to the developing world.

There follows an interesting discussion of what will be needed from the five most rapidly developing nations – China, Brazil, South Africa, Mexico and India – and then from the major industrialised countries, noting in the case of the US the new hope that President Obama has brought to the possibility of effective action.

The book concludes with a reminder of actions we can take as individuals to contribute in small ways towards the result.  I appreciated the final paragraph urging us not to despair. “The climate problem is certainly a hard one, but it’s not intractable.” This statement is backed up by a map of the world showing six small squares distributed through the various land masses which would together provide enough energy to power the entire world’s requirements once we learned to capture sunlight efficiently.

The authors describe their aim as being “to tell you everything you wanted to know about global warming but were too depressed to ask.”  Readers who know that depressed feeling may be reassured by the book, though there is nothing facile about its optimism. Indeed there is an element of doggedness in the iteration that now is the time to act, not to despair. A doggedness, I hasten to add, that I am happy to share. The political solution is the sticking point.  I found the book particularly useful in its explanations of the issues in international negotiations and how they might be tackled successfully. The authors may not be politicians, but they draw on experience of the political world  and display a good understanding of how things work there. The interested reader will find complicated matters explained with admirable lucidity.

Censoring Science

Censoring Science: Inside the Political Attack on Dr. James Hansen and the Truth of Global Warming

It’s Official: Griffin is Gone. That’s the heading on Mark Bowen’s blog on 27 January.  He forbore to add the exclamation mark that tempted him. You would understand this as a noteworthy piece of news if you’d read Bowen’s book Censoring Science: Inside the Political Attack on Dr. James Hansen and the Truth of Global Warming published in January as a Penguin paperback. (The hardback edition appeared in 2008.)  In his book Bowen is clearly suspicious of the role that Michael Griffin, appointed Administrator of NASA in 2005, played in the attempt to censor James Hansen which the book details. Incidentally, Bowen has recently set out very clearly in this long entry on his website the case against Griffin in a more connected way than he was able to establish when writing the book.

To turn to the book. The author, a writer, has a doctorate in physics and wrote a much-praised climate change book Thin Ice in 2005. Bowen’s mountain-climbing expertise enabled him to join climatologist Lonnie Thompson in some of his heroic expeditions to high and remote ice caps to gather ice core records. The association with Thompson opened his mind to the clear and present danger of global warming.   In Censoring Science he moves to the work of another distinguished climatologist, though this time one he hasn’t had to follow into forbidding terrain.  James Hansen directs the research at NASA’s Goddard Institute for Space Studies (GISS), much of which is centred on factors affecting climate change. Twenty years ago he delivered a now famous congressional testimony showing early models predicting increased global warming, and he has remained at the forefront of scientific understanding of the effects of increased levels of CO2 in the atmosphere.

Irony attends the scientific realisation of the dangers of anthropogenic global warming:  many of the finest scientists engaged in it are American, yet America (and for a time its faithful shadow Australia) is the one developed country which long refused to treat the question as of moment for the future of humanity.  The irony is no accident.  Bowen’s book describes some of the workings of an administration which not only denied or ignored the science but also tried to prevent the public being made aware of it. Much of his investigation centres around events in late 2005 when Hansen gave a lecture to an American Geophysical Union meeting in which he set out the possibilily of tipping points ahead if fossil fuel CO2 emissions continued at their current rate.  He spoke of the vast scale of losses due to world wide rising seas under such a scenario, and called for prompt action to keep further global warming under one degree centigrade.  He added a comment that it seemed to him that special interests had been a roadblock wielding undue influence over policymakers. Two days later the GISS global temperature results for 2005 were posted, showing it to be one of the warmest years on record.  It’s beyond the scope of a short book review to detail the consternation amongst political appointees to the staff at NASA, and the steps that were taken to try to ensure that Hansen was put on a short leash.  To follow it closely would also require a better knowledge of the workings of NASA administration and agencies than I have.  But the thrust of Bowen’s careful narrative is clear There was an attempt, not only then but at other times, to muzzle Hansen and other scientists and to tamper with the conclusions to which their scientific work pointed.  The White House itself appears to have have been a driving influence in the background.   It is part of the widespread suppression of science under the Bush administration, much of it centred on climate change, but extending into other fields as well.

It’s a disturbing story. NASA’s mission statement was quietly altered in February 2006 to drop the phrase “to understand and protect our home planet”, ostensibly to square it with Bush’s focus on pursuing human spaceflight to the Moon and Mars.  This went hand in hand with cuts to funding of earth science projects such as those which depend on satellite measurements to provide critical information about Earth processes.  Funding cuts are an obvious way of stifling scientific discoveries.

Hansen did not submissively accept restrictions on his ability to communicate with the general public. He is not a person to shrink from what he sees as a duty, albeit expressed in modest terms. “I don’t want, in the future, my grandchildren to say, ‘Opa understood what was going to happen but he didn’t make it clear.’ And so I’m trying to make it clear.”

Thankfully Hansen’s combativeness meant that the authorities failed.  He remained in his position and continued to work as the scrupulous scientist he is, sharing his science and his concerns with a wider public when he feels he needs to.

Much of the book is devoted to Hansen himself, his work, the progress of his thinking over time, his background and character.  Bowen builds a picture of a relaxed but dedicated man who spends long hours in the science which has absorbed him for years. These parts of the book provide a narrative of Hansen’s growing understanding of the complexities of global warming and awareness of its latent dangers.  Bowen himself is well equipped to understand the science and his explanations are clear and helpful.

The book’s story ends in 2007.  Since then Hansen has if anything become more involved, in his capacity as a private citizen, in seeking to prod governments into activity.  He has also continued to do solid scientific work, which has included recently his and nine others’ paper Target Atmospheric CO2: Where Should Humanity Aim? which suggests that we need a reduction from the present level of 387 parts per million of CO2 in the atmosphere to 350 ppm or less if humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted.

Is it naivety which guides Hansen in his expectations of how the public will react to the scientific picture if only they understand it?  Bowen quotes approvingly journalist Bill Blakemore who thinks it’s something closer to what Yeats calls ‘radical innocence’, a kind of transparent integrity. Whatever it is, long may it continue.

Getting on with the job

Carbon Neutral by 2020: How New Zealanders Can Respond to Climate Change

Carbon Neutral by 2020: How New Zealanders Can Respond to Climate Change is in many ways a cheering book though its title, which was right on the mark when the book was published in 2007, has an aura of faded hope to it now. That fading is largely due to the many New Zealand business and farming leaders who continue to oppose any government move which might be effective in addressing climate change, and a new government which still doesn’t seem to know whether it’s going to take the issue seriously or not.  But the depressing backtracks of government and success of negative lobbying don’t obscure the fact that this book is a sensible publication which accepts the reality and looks at how we can get on with responding to it positively.

The editors are Niki Harrė and Quentin D. Atkinson, both psychologists.  They recognise that climate change is a tough call for the human psyche.  It can seem too big an issue for individuals to affect.  But they want us to own the problem and to find a sense of purpose and belonging in doing so.

They have gathered contributions from a wide range of experts covering many aspects of New Zealand life. The sustainable school programme has large potential for change in community attitudes now and in the future adult population. Housing and home renovation are key elements in reducing energy consumption. The shopping mall of the future offers many opportunities for carbon emission reduction. Computing can contribute on many fronts. The book follows the vision of a carbon neutral New Zealand by 2020 into these and several other segments of our national life – transport, organics, design, ethics, ethical investment, sustainable business, law and political action

What that vision might mean for each segment is pursued in detail, along with the strategies we would need to follow to get us there. In the section on sustainable design, for example, the vision is for a use of resources that does not jeopardise the needs of others on the planet or those of future generations. The strategies include new ways of designing which move us away from the landfill destination to objects designed so that every component can be separated and used again indefinitely.  Interestingly, the writer stresses that design can’t be considered in isolation from our governing and finance systems which militate against such a responsible approach to resources.

This theme of appropriate political and economic settings is never far away.  A central aim of the book is to let individual readers see what they can do in the organisation of their own lives and communities and businesses to contribute towards carbon neutrality. But the various writers are also often fully aware of the wider societal changes that are needed and how we might influence their direction. The chapter on transport, for example, includes steps individuals can take in reducing car use but is largely concerned with the government policy measures needed to change the transport systems so that we have much less need to rely on cars.

It is heartening to read authors in such a wide variety of sectors who are concerned about climate change and have a vision of how it can be addressed in their area of expertise. We need a sense of common concern and common effort in an overwhelmingly important issue. Books such as this reveal a more widespread readiness to confront the crisis than we might credit and encourage us to share in it.

But it remains seriously disappointing that our politicians haven’t come together as they should to communicate solidarity in tackling the questions.  It is hard to see the sort of goals presented in the book achieving realisation without strong governmental support.  So long as government remains tepid there is little chance of the general populace realising that we face a crisis which must be addressed, and little chance of the redirection of the economy which is central to change.  The final chapter of the book is on political activism, which seems to me to continue to be essential for success on the scale required.

This is not the sort of book one should expect to read in one swoop. It has many authors and each section needs separate attention. It could be considered a handbook for readers who want to find ways of engaging with the challenge confronting global society.  The editors have brought together an impressively varied selection of useful material. Publisher Craig Potton have played their part too, not only bringing to the public a book which engages with important issues but also treating it as an opportunity to practise emissions minimisation themselves, as explained in their publisher’s note.

The Long Thaw

The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth's Climate

The legacy of our release of fossil fuel CO2 to the atmosphere will be long-lasting. It will affect the Earth’s climate for millenia. We are becoming players in geologic time. That is the conclusion that climatologist David Archer shares with a general audience in his newly published book The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth’s Climate.

The author is a professor in the Department of The Geophysical Sciences at the University of Chicago and a contributing editor at Real Climate. His book is relaxed in style, almost conversational sometimes, repetitive on occasion, but nevertheless closely focused and packed with instructive detail. It was a pleasure for a non-scientist like me to read. He seems to understand how to illuminate processes for the general reader. For example, his chapter on the distribution of carbon in the atmosphere, the land and the ocean, and his explanation of the interactions between them in the carbon cycle, provided angles and information that pulled together satisfyingly the bits and pieces of my hesitant understanding.   Similarly what he writes about the acidifying of the ocean by CO2 and the part calcium carbonate plays in slowly neutralising its effect is a model of lucidity.

The book’s structure is simple.  There are three sections.  The first describes the situation we are in right now – meaning the 20th and 21st centuries.  The second section is about the past, investigated as a forecast for the future.  The final section looks into the deep future.

Archer produces no surprises about our current situation.  The basic physics of the greenhouse effect – that gases in the atmosphere that absorb infrared radiation could eventually warm up the surface of the earth – was described in 1827 by the French mathematician Fourier. Then in 1896 Swedish chemist Arrhenius estimated the amount of warming that the Earth would undergo on average from a doubling of the atmospheric CO2 concentration – what we now call the climate sensitivity. Such work sets the scene for the climate science which has exploded in the past few decades as global warming grew from a prediction into an observation.    He describes many aspects of our current understanding of global warming, with several particularly helpful sequences, such as that on the relative strengths of four external agents of climate change called climate forcings – greenhouse gases, sulfur from burning coal, volcanic eruptions, changes in intensity of the sun. The warming that is occurring cannot be explained by natural forcings.  Looking ahead in the present century he is very aware that sea level rise by 2100 may well be higher than predicted by the IPCC, as it begins to appear that the ice models used to forecast may be too sluggish to predict the behaviour of real ice.

In the second section he moves steadily back in time, starting with the last 100,000 years where the abruptness of some of the changes detected leads him to reflect that the IPCC forecast of a smooth rise in temperature from 0.5 degrees excess warmth today  to about 3.0 degrees excess warmth in 2100 represents a best-case scenario in that it contains no unfortunate surprises. He then treats the longer-term glacial climate cycles through the last 650,000 years, paying attention to orbital forcing and to the ups and downs of atmospheric CO2 through the cycles.  He envisages the ice sheets and CO2“entwined in a feedback loop of cause and effect, like two figure skaters twirling and throwing each other around on the rink.” His final step back is to the hothouse world of 50 million years ago and beyond that to transitions between hothouse and ice age climates over 500 million years. He selects the Paleocene Eocene Thermal Maximum event (recently discussed on Hot Topic) as an analogue for the global warming future.

The third section looks at that future.  In discussing the land’s and ocean’s ability to take up carbon being released from fossil fuels he considers it likely that there are limits to that process which will mean that a significant fraction of fossil fuel CO2 will remain in the atmosphere for millenia into the future.  There are calming effects from the carbon cycle, but there can also be opposite effects as seems likely to have been the case at times in the past.  Hopefully large scale methane hydrate release won’t be a large part of such feedbacks, but if the ocean gets warm enough it is possible and could double the long-term climate impact of global warming.

For now the carbon cycle is responding to the CO2 increase by inhaling the gas into the ocean and high-latitude land surface, damping down the warming effect. But on the timescale of centuries and longer the lesson from the past is that this situation could reverse itself, and the warming planet could cause the natural carbon cycle to exhale CO2, amplifying the human-induced climate changes.

The clearest long-term impact of fossil-fuel CO2 release is on sea level rise.  The book has a restrained chapter on this, but there is no escaping what will happen if the ice sheets melt. “We have the capacity to ultimately sacrifice the land under our feet.“

Have we averted an ice age?  Archer discusses this possibility, but finds the evidence uncertain.  He would in any case not put such a possibility forward as an argument in favour of CO2 emissions. All it means is that natural cooling driven by orbital variation is unlikely to save us from global warming – at this stage the much greater danger. Incidentally he mentions Ruddiman’s book Plows, Plagues, and Petroleum briefly and appreciatively in this section, but gives reasons for doubting its conclusions. (The book was reviewed on Hot Topic recently.)

In his epilogue on economics and ethics, where he ponders whether we are likely to turn away from the path we are currently on, he offers a comparison with slavery, another ethical issue: “Ultimately it didn’t matter whether it was economically beneficial or costly to give up. It was simply wrong.”

James Hansen describes the book as the best about carbon dioxide and climate change that he has read.  “David Archer knows what he is talking about.” To which I would add that he also knows how to explain it clearly to anyone prepared to give him reasonable attention.