Tag: Book reviews

Preparing for Climate Change

Preparing for Climate Change (Boston Review Books)

The global climate is changing. The impacts on human society are likely to be very serious. We would be foolish indeed not to plan ahead for coping strategies. Michael Mastrandrea and the late Stephen Schneider have produced a small book setting out what we can best do to be ready for what is in store.  Preparing for Climate Change is one of the Boston Review Books, a series of “accessible, short books that take ideas seriously”.

It’s a thoughtful, well-organised piece of writing which leads the reader by steps through what is needed to prepare for what climate change will  bring. The first step is to understand that global warming is for real. It’s under way and it is largely due to anthropogenic forces. However predicting its future course is difficult because of two things we don’t know — how much more greenhouse gases humans will emit and exactly how the natural climate system will respond to those emissions. The temperature rises we face will depend on the level of emissions, and the range of projections for the year 2100 that the IPCC has estimated on the basis of six different scenarios is very wide, from as low as 1.1 degrees to as much as 6.4 degrees. The latter could be catastrophic. The former looks increasingly likely to be well surpassed. But even a comparatively low level of temperature rise would bring damaging changes for some communities and ecosystems. Indeed the 0.75 degree increase of the past century is already showing some worrying impacts.

The authors then outline the key vulnerabilities that need to be taken into consideration. They include glacier loss, melting ice sheets, sea level rise, higher infectious disease transmission, increases in the severity of extreme events, large drops in farming productivity especially in hotter areas, the loss of cultural diversity as people have to leave their historical communities, and an escalating rate of species extinction. Many of these can already be witnessed in their early stages, and the book provides examples from various parts of the globe. Additionally, however, there is the possibility of “surprises”, fast non-linear climate responses which may occur when environmental thresholds are crossed. Some can be imagined, such as a collapse of the North Atlantic ocean currents or the deglaciation of Greenland or the West Antarctic ice sheets. But because of the enormous complexities of the climate system there is also the possibility of unforeseeable surprises.

In the face of inherent uncertainty we have to proceed by risk assessment and risk management as we make our policy decisions.  Risk assessment is primarily a scientific enterprise. Risk management – deciding which risks to tolerate and which to try to avoid – is a political matter where values enter into play.  However the relationship between the two is complicated by the uncertainties of the scientific predictions. These uncertainties will be reduced as research proceeds under normal scientific practice, but answers of some kind are needed well before this time. There are policy decisions to be taken before there is a clear consensus on all the important scientific conclusions. The authors discuss type I and type II errors at this point. A type I error will be committed if we act to mitigate climate change and discover that our worries prove exaggerated and anthropogenic greenhouse-gas emissions cause little dangerous change. A type II error will be committed if we delay action until greater certainty is established and in the process allow serious damage to occur. We have a choice as to which type of error it is better to avoid.

What actions does sensible risk management indicate? We know that reducing emissions will reduce the level of temperature increase that would otherwise occur, but we also know that further climate change will happen no matter how quickly we are able to reduce emissions. We must therefore both try to limit future emissions and at the same time adapt to what we cannot escape.  Mitigation and adaptation must be complementary and concurrent.

The authors recognise some adaptation as autonomous; it is reactive in response to the impacts of climate change. However they consider it vital to also plan adaptation. Planned adaptation may be reactive, but the book lays stress on planning which is anticipatory, as for example in the protection of coastal infrastructure.  Anticipatory adaptation is an investment, but one which may not be able to be afforded by poorer developing countries. The book notes that the Copenhagen Accord recognised this and included a commitment to provide resources for adaptation investment in such countries.

But adaptation measures can only go so far, and mitigation must be seriously pursued in tandem. Although the book focuses a good deal of its attention on how we can plan for adaptation it is clear that there must be a mix with mitigation measures adequate to keep adaptation manageable.  The third more drastic response to climate change of geoengineering is briefly considered, and described as desperate: understandable, but not what the situation demands as a first response.

Whatever mix of mitigation and adaptation we adopt the authors are firm that equity issues must be part of planning. The needs of vulnerable and marginalised groups must be a prominent consideration when forming climate policy.

The question of vulnerability is faced in their final chapter. They see vulnerability assessment as an essential tool to inform the development of climate change policies.  Exposure to stress, sensitivity to the exposure, and adaptive capacity are the three components which need to be considered. Mitigation reduces vulnerability by reducing exposure. Adaptation reduces vulnerability by turning adaptive potential into adaptive capacity. New Orleans before Katrina had quite high adaptive potential, but it was not realised and adaptive capacity was therefore low. Vulnerability assessment is a complex task and they argue for a close relationship between those on the ground in specific regions (bottom-up) and the climate-impact assessments of scientists (top-down). Again, questions of justice are high in their priorities.  We must be sure that marginalised countries and groups are not ignored as we tackle the potentially dangerous, irreversible climate events ahead.

For those familiar with the subject the ground the book covers is probably not new.  But the writers are authoritative and their treatment is well organised and logically ordered. It is also informed by a strong sense of humanity. Their book is an excellent short statement for the general reader and a useful summary analysis for those who appreciate a reminder of how the various elements fit together. Don’t be misled by the moderate tone or the acknowledgement of the uncertainty which must attend predictions of future change. The authors know they are writing of an urgent and pressing need to prepare in advance if we are to avoid the worst consequences of climate change.

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The Flooded Earth

The Flooded Earth: Our Future in a World without Ice Caps

Paleontologist Peter D Ward is scared and not afraid to admit it. He doesn’t mince matters in his latest book The Flooded Earth: Our Future in a World Without Ice Caps. His own study of Earth’s geological past makes him well aware of what changes to the ice caps can mean for sea level and also of how closely past temperature rises and falls have been tied to levels of atmospheric carbon dioxide. He is alarmed by the prospect for this century and also for the centuries ahead if we keep loading the atmosphere with carbon dioxide from fossil fuels. Over coming centuries we can expect metres of sea level rise at a minimum, and much more if there is rapid disintegration of one or more ice sheets. His example of how rapid change can be is a rise which occurred during the most recent ice melt 14,000 to 16,000 years ago when the sea appears to have risen by nearly 50 feet over 300 years.

Scientific reticence is not for him. He discusses it at one point in the book. In relation to sea level rise he considers the fear of being wrong is inhibiting the sounding of the alarm that new discoveries call for. He refers to James Hansen on the question of caveats and caution. Hansen regards caveats as essential to science, but warns that there is a question of degree and “gradualism” as new evidence comes to light may not be appropriate when an issue is pressing. Ward welcomes the robustness of Hansen who says he expects more than 3 feet sea level rise by century’s end. Ward also notes climatologist Stephen Rahmstorf’s recent estimate, based on a new kind of model, of a minimum of 2 feet and a maximum of almost 5 feet this century. Ward doesn’t himself settle on a particular figure for this century, but has no doubt that the rise will continue so long as carbon dioxide levels are permitted to continue to rise, and that it will be very difficult for human society to cope with.

The book has many warnings to give about what rising sea levels will mean. They are pitched to the understanding of non-specialist readers and they bring into focus the work of a wide range of researchers in a variety of fields. One area of major concern is how even a modest increase in sea level will dramatically affect world agricultural yields. Some land will be drowned, but Ward draws particular attention to salt intrusion from the sea in agricultural areas near to oceans. A detailed examination of the Sacramento Delta region in California illustrates just one highly susceptible area. Ward considers the world overpopulated, and the prospect of feeding 9 billion or more people is certainly not enhanced by encroaching sea water.

It is estimated that even an 8-inch rise in the Bay of Bengal will displace 10 million Bangladeshis in an already heavily populated country.

The flooding of threatened countries and cities as sea level rise gathers pace is the focus of another chapter of serious warning. Bangladesh and Holland are two countries he discusses. It is estimated that even an 8-inch rise in the Bay of Bengal will displace 10 million Bangladeshis in an already heavily populated country. A 3-foot rise in sea level will put Holland on the ropes; a 16-foot rise will knock it out, flooding huge areas and displacing millions. Venice and New Orleans feature in his discussion of cities, but he points to myriad coastal cities which will face neighbourhood triage – deciding which areas to fight for and which to give up. If sea level rises much beyond 5 feet expensive infrastructure will be threatened and some enormous economic blows suffered. Airport runways in San Francisco, Honolulu, and Sydney will be the first to go. In many cases it will be more cost-effective to abandon coastal cities rather than try to protect them.

Ward frequently offers imaginary scenarios at various stages of the future, ranging from twenty years through to several hundred or even thousand years. They are not comforting, but they are all too possible if we refuse to take seriously the effects our fossil fuel habits are having on the global environment. His picture of what effect the Canadian operations to extract oil from tar sands will have had by 2030 if they continue is shocking – the desolate, devastated landscape, the health and environmental hazards visited on the First Peoples, the vast increase in carbon dioxide emissions. Another imaginary picture in 2045, with carbon dioxide levels at 450 ppm, portrays the last visit of tourist divers to Osprey Reef in the Coral Sea. The reef has changed tenants. Its once-numerous corals have been replaced by microbes that thrive in hot, acidic water. No longer a coral reef in the Coral Sea, it has become a bacterial reef in the Bacteria Sea. A more distant scenario is in 2400 on the Bangladesh-India border. Carbon dioxide levels are at 1200 ppm. More than half of Bangladesh is under water. He pictures a mass border breakthrough of a tide of humanity met by tactical nuclear weapons killing fifty thousand Bangladeshis instantly and many more in weeks to come.

One can hear the scoffing of denialists and delayers. But I found nothing alarmist in the scenarios.  What else do we think is going to happen as the seas continue an inexorable rise brought on by the gradual or more than gradual disintegration of the ice sheets? Ward knows what the ice sheets mean for sea level. He also knows what elevated carbon dioxide means for global temperature. Earth has been through this before. The difference this time is that it is our own doing and that it is happening to a planet heavily populated with human beings.

The book includes a chapter titled “Extinction?”. The question mark was a small relief. Here he discusses his concern at the eventual possibility of a slow changeover of the oceans through global warming from their current “mixed” states to a stratified state which in the past has always been a prelude to biotic catastrophe. The chapter recapitulates briefly the argument of his previous book Under a Green Sky, reviewed here, and emphasises the contributory role of sea level rise to the process of slowing oceanic currents and interrupting the mixing of oxygenated top waters with those below. In his view this is a point where we need to see a vital connection between ancient climates and impending climate change. He observes that the media have not allowed scientists to make this case, not because they disbelieved it but because the past scenarios were too horrifying for us to contemplate their happening again, and soon.

There’s an element of understandable desperation in Ward’s final chapter. It considers carbon sequestration possibilities through afforestation, charcoal burial, acceleration of natural weathering processes and other measures. Also, albeit with not much conviction and some trepidation, it canvasses major geo-engineering proposals to which we may be driven in extremity.

I found Ward’s book hard to put down. He draws out the implications of what we already know with clarity and force. That is a most valuable service. The more scientists will overcome their inclination to reticence and share their fears with the general population the better. Any risks in doing so pale beside the consequences of not doing so.  We must be faced with the full reality of what we are doing to the climate while we can still escape the more extreme consequences.

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From Smoke to Mirrors

Kevin Cudby doesn’t rush to easy conclusions in his new book From Smoke to Mirrors: How New Zealand can replace fossil liquid fuels with locally-made renewable energy by 2040. He is clear that fossil fuels must be eliminated but seeks to be realistic about how that can be done. The focus on New Zealand is not exclusive; however, he considers that New Zealand can provide an example which many others will want to learn from and follow. There’s also an economic imperative that we be able to show those who holiday here or buy our products that they are not thereby exacerbating climate change. Cudby envisages a society continuing to have the transport opportunities we currently enjoy and depend on, but fuelled differently. He fully accepts the warnings of climate science, taking James Hansen as a guide in that respect.

The book painstakingly leads the reader through a wide variety of technologies relevant to its search.  Battery vehicles receive close and sympathetic attention but are seen as unlikely to be sufficiently developed to be widely used in NZ road transport before 2040, though they may well make sense for some transport businesses. In discussing hydraulic hybrid (rare as yet) and plug-in battery hybrid vehicles he notes that their low fuel consumption will cancel out rising fuel prices. Hydraulic hybrids should have proved by 2020 whether they can deliver what the promoters promise; he certainly sees them becoming common on machines such a ditch diggers. Hydrogen fuel cell vehicles show much promise, and he sees a future for them in New Zealand, though not in significant numbers before 2040.  The discussion of these differently powered vehicles is illuminating in its detail, with very useful explanations of how they work and what problems have yet to be overcome in each case.

Liquid fuels will continue to play a major part in NZ transport by 2040, in the author’s view. They will also remain essential in non-road equipment and vehicles, which Cudby frequently reminds the reader are substantial users of fuel. It will not be enough to eliminate fossil fuels from road transport. Air and sea travel must also be fuelled from non-fossil sources. At this point in his book the Biomass Gasification and Fischer-Tropsch (BGFT) process enters the scene. It yields synthetic crude oil that can be converted into diesel, kerosene, fuel oil, and petrol. BGFT fuels directly replace conventional liquid fuels. They work best with dry biomass. They are expected to be commercialised by 2015, and although they will be more expensive than conventional fossil fuels their use should not affect transport costs because improved vehicle efficiency will offset the higher cost. Cudby estimates that to provide sufficient biomass to satisfy its entire liquid fuel requirements with BGFT synthetic fuels New Zealand would need purpose-grown energy forests covering between nine percent (low scenario) and thirteen percent (high scenario) of its total land area. Excluding from consideration native forests and conservation areas, as well as arable or high quality pastoral land, he finds that between 29 percent (low scenario) and 40 percent (high scenario) of steep low quality land would suffice for the energy forests. I was reminded of the report in 2006 of the Energy Panel of the Royal Society of New Zealand 2020: Energy Opportunities which envisaged a rapid transition to carbon-neutral transport fuel and produced an analysis which demonstrated that New Zealand can easily grow the required biomass without impinging on productive soils.

The book also considers the Hydrothermal Liquefaction (HTL) process, a likely useful complement to BGFT because it copes well with wet biomass and is a promising candidate for converting microalgae into liquid fuels as he notes NZ company Solray Energy is demonstrating. Algae biofuel receives attention but Cudby sees it as not yet ready for commercial-scale stand-alone fuel production. Biodiesel, which he differentiates from synthetic diesel such as BGFT or HTL, is not an option for running the NZ transport system but could fulfil a very useful niche role as a lubricity additive to synthetic diesel. Ethanol will have a role, but for the present its high cost and inferior environmental performance compared with synthetic hydrocarbons tells against it.

This general outline does little justice to the detailed coverage Cudby gives to all these and many related topics as he outlines the options for transport and non-road liquid fuel use. The technically inclined reader will be well engaged. As the author proceeds to his assessment of the options he acknowledges that the world’s transport systems will eventually depend on solar fuels, hydrogen, batteries, or perhaps algal biofuels. However for now none of them are competitive with conventional vehicles fuelled by synthetic biofuels. While we wait to see which technologies will ultimately succeed we should get on with the decarbonising of our supply of liquid fuels. He proposes opening renewable energy facilities at 18-month intervals beginning in 2018. The first six factories would make hydrocarbon liquid fuels. Thereafter it would depend on how world technologies are developing. The products of the first factories would certainly be needed during a 20-year investment life of the factories.  Energy forests have a twenty-five year rotation and he looks to an acceleration of the process in the first stages by using some existing forests for energy, by planting trees close together and harvesting them sooner, and by using unwanted pine trees, gorse and other scrubby weeds.

There are two distinct stages to the transition. The first is replacing the essential hydrocarbon fuels, that is, non-road petrol and diesel, aviation kerosene, and fuel oil. The second is carbon-neutralising road transport, which may involve the vehicles as well as the fuels and perhaps include a mix of different technologies.

It can be done by 2040 but in Cudby’s view it won’t happen as a result of carbon pricing schemes, whether by emissions trading or a direct tax. Energy companies will continue to pursue the enormous potential for liquid fuels made from natural gas, tar sands, heavy oil, oil shale, coal, and methane clathrates. We must therefore progressively ban imported fossil fuel as we develop our biomass synthetic fuel, and while we are about it ban indigenous fossil fuels as well.

“…the only foolproof way to eliminate fossil fuels is to outlaw them”. This is an eminently sensible thing to say, especially when the writer has set out in considerable and thoughtful detail how they can be replaced. But as I read this section of the book I tried to imagine our Minister of Energy engaging with it and failed. In fact he is doing precisely what Cudby says the energy companies will continue to do, pursuing fossil oil to its last drop, holding out a promising future for coal and expressing hope that methane clathrates can be tapped.

Full marks to Cudby and others like him for a thorough and patient exploration of the means by which we can end our reliance on fossil fuels. His vision of New Zealand showing the way, able to demonstrate renewable fuel in almost every type of vehicle even invented, is not bombast but technically grounded.  “What are we waiting for?” are his final words. To which I fear the answer is political leadership intelligent enough to understand the danger of climate change and resolute enough to take a lead in tackling it. And voters ready for such leadership. Technologically, if Cudby is right, we are ready, but politically is another matter.

The Climate Connection

The Climate Connection: Climate Change and Modern Human Evolution

The authors of The Climate Connection: Climate Change and Modern Human Evolution are deeply aware of the threat to human survival accompanying our rising greenhouse gas emissions. Renée Hetherington and Robert G.B. Reid suggest that a better understanding of our past evolutionary relationship with climate may point to how we may yet make the future more hopeful than it presently seems. Not because the climates homo sapiens has had to live with in the past resemble what we are laying up for our future, but because the authors see elements in past human responses from which we might learn if we will.

The book covers a wide field, dealing with the emergence of modern humans, the dispersions and migrations of human populations, the climate changes of the last 350,000 years and the interaction between climate and humans during that time, concluding with reflections on our future in a very different climate environment. The survey is designed for those with courses of study in view or already working in the area and is hence often demanding for the general reader. It contains much detailed and carefully referenced information in its pages. However its underlying themes are regularly stated and provide ample bearings for readers for whom the territory is not familiar.

In discussing human behavioural evolution the authors espouse the working hypothesis that from the outset homo sapiens has had the potential to express the same thoughts, ideas, communication, spirituality, artistry and technical complexities as our own brains. But a combination of environmental conditions, both favourable and stressful, and increased social complexity was needed to bring out that potential. Robert Reid, a biologist, is a proponent of emergent evolution and a critic of the adequacy of natural selection theory. The book argues that environmental and climate connections have elucidated rapid changes in human behaviour in the past. Adaptability is required under conditions of stress and climatic instability which demand disregard of old ways and the adoption of new. Such adaptability has been demonstrated in human populations.

The book makes a long and careful journey looking for times when rapid behaviour change might have occurred. The “out of Africa” hypothesis underlies the authors’ survey, with much attention paid to early human mobility and migration. Geographical barriers to human movement, expansive coastal plains exposed when sea level fell during glacial periods, possible congregation of populations in productive refugia in glacial periods leading to increased genetic exchange, are among the factors the book considers as it surveys the evidence of the dispersal of behaviourally modern humans in the various regions of the world. The authors give especially close attention to the Americas where they have a greater research background.

A substantial section of the book examines climate during the last glacial cycle in considerable detail. It includes an excellent description of climate change forcing mechanisms. The authors have recently used the UVic Earth system climate model, which they describe as of intermediate complexity, in a project to understand the world’s changing climate over the last 135,000 years. Combining modelling with proxy indicators they try to reach a best estimate of the climate and its effects on vegetation over a number of different stages during that time. This is the changing world that our ancestors moved through and inhabited.

What did the changes mean for those ancestors? The book frankly acknowledges the huge gaps in any picture we can hazard constructing. The words ‘may’ and ‘likely’ occur frequently.  But it painstakingly matches any fossil and archeological evidence that can be matched and emerges with some general observations which certainly seem worthy of consideration. One in particular sounds a theme recurrent in the book. In the course of the glacial cycle they see probable migration out of deteriorating regions and into more habitable areas where disparate groups would be periodically placed in social contact with one another. It is this sort of social interaction that they consider likely to have stimulated the emergence of intelligence and the development of new ideas and technologies. Eventually the relatively more settled climate of the Holocene led to the development of agriculture which allowed humans to directly manipulate the unpredictability of nature, albeit sometimes precariously as the chapter surveying the history of agriculture makes clear.

Is all this any help as we face a climate changing because we are causing it to change, with prospect of an altered kind of world from that in which human civilisation developed?  We’re in a different situation from our roving ancestors. The authors point out that there are 6.75 billion of us now, expected to rise to over 9 billion by 2050. The global dominance we have achieved as a species has been achieved as we have discovered how to manipulate our environment. But with environmental manipulation has come the unintended consequence of human-caused climate change bringing the threat of severe economic and social instability. On a planet so heavily populated and whose resources are so stretched it is not possible to replicate a past when humans could migrate to new regions relatively unobstructed.

What then can we learn from the past experiences of our species?  It has to be said that the authors are hardly confident as they address the question towards the end of the book. However they do their best. In our past real changes in behaviour occurred when humans experienced significant environmental stress. They note that major environmental stress is clearly predicted in our future, so behavioural change may potentially be on the way. But they recognise that the problem is that we must change now before climate change puts us under those stresses. In effect, then, they suggest anticipating the stresses and opting for changes before they are forced upon us. Even as they do so they recognise that it’s by no means clear that we can manage this. For example they rather chillingly refer to Jared Diamond’s Collapse which speaks of ‘creeping normalcy’ as a major reason why people fail to recognise a problem until it is too late. Further, they note that Diamond states that even when the problem is recognised societies frequently fail to solve it because people are highly motivated to reap big, certain and immediate profits, while the losses are spread over large numbers of individuals.

Nevertheless in spite of all the negative possibilities the authors emphasise that the important message from past human interactions with climate is that we should work co-operatively in finding innovative solutions which will lead to the global sustainability which we have placed under threat. Revolutionary ideas have been stimulated in the past in response to rapidly changing environmental conditions and as a consequence of concentrating populations. Reluctance to change leaves us highly vulnerable to decline, and even extinction.

This advice is hardly new. It comes at us from many directions. But for the authors of this book it is reinforced by all they know of the long story of our species. The intrinsic interest in what they have to tell of that story is enhanced by their ever present sense of how it might assist us in understanding and confronting the challenges ahead for our species.

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The Weather of the Future

Weather of the Future: Heat Waves, Extreme Storms, and Other Scenes from a Climate-Changed Planet

Heidi Cullen takes readers forty years forward in her survey of what is likely to happen in several areas of the world if we continue to burn fossil fuels. Her book is The Weather of the Future: Heat Waves, Extreme Storms, and Other Scenes from a Climate-Changed Planet. It is a highly effective communication to the lay person of what climate science predicts for the specific areas she has chosen to explore. Cullen, a climatologist, works as a senior research scientist for Climate Central, an organisation set up in 2008 to act as a central authoritative source for climate change information.

Before moving to the selected areas for closer examination she offers some lucid general introductory chapters, including a very useful explanation of the use of modelling in climate prediction. In response to the question of when the weather will start to reflect predictions about the climate she answers that it already has in extreme weather events. If greenhouse gases continue to rise, the way weather affects life on Earth will be far worse than anything we’ve ever seen before. ”Can we rally around this forty-year forecast for the good of the world, or will we wait until the levees break before we decide to act?”

The first area Cullen surveys is the Sahel region of Africa.  She talks with climatologists who work on understanding the rainfall patterns and outlook for the region.  The picture is complex, but there is no doubt that the region is going to get warmer. All the models agree on that. They show some variation on the expected amount of rainfall, but it seems likely that the rainy season will start later and become shorter, with storms that will possibly become more intense. Pockets of resilience offer some hope from farmers who have turned to tree planting with considerable benefits to their crops and welcome extra income from the trees. But as Cullen takes her projections forward she remarks that there is only so much the trees can do against the increasing reality of climate change. Socially, climate change will become a threat multiplier as conflict spreads across the African continent in lockstep with temperature.

The next selected area is the Great Barrier Reef. Cullen talks with Joanie Kleypas, a marine ecologist and geologist who uses climate models to study the health of coral reefs. “I work on coral reefs, for God’s sake. The entire coral science community is depressed.” The chapter provides very clear accounts of the bleaching effect of warming oceans (“Bleached corals aren’t dead; they’re just starving.”) and the deleterious effect on coral growth from ocean acidification. The speed of both warming and acidification is likely to quickly outpace the conditions under which coral reefs have adapted and flourished through past changes. They are unlikely to be able to adapt fast enough. It’s not a good outlook. Cullen allows herself a detour to point to other and more dramatic effects of climate change that Australia is set to encounter – ferocious wildfires, pervasive drought, and unbreathable air. The lucky country looks anything but in coming decades.

The US is a leading per capita contributor to global emissions. It has not yet accepted the level of responsibility it carries. Other places, far less responsible and much poorer, are bearing the early consequences of global warming. But that doesn’t mean the US will remain exempt from any serious consequences, and it was good to see Cullen turning to her own country for two of her chapters, and driving home that message.  One of the places she selects is Central Valley, California.  The Sacramento-San Joaquin Delta is a focus of her attention here. It’s the hub of California’s water supply system. The Hollywood-style dream is that the Delta will be able to supply enough clean fresh water to help cities and crops increase “forever”, all without harm to the natural environment, she notes dryly. She speaks with a multidisciplinary team studying the Delta, which in reality has far more in common with New Orleans than with Hollywood. The details of the problems and threats are canvassed and the extreme vulnerability of California to coming water shortage exposed. Her other US focus is New York city. Here it will be energy blackouts which threaten as the average temperature increases over coming decades. The power grid is unsuited to climate extremes. The other major area not ready for what lies ahead is flood protection.  However planning is going on in New York to develop resilience to what the changed climate will deliver, and also to mitigate the city’s emissions.  Cullen imagines a time four years from now in which, following damage from a storm, a co-ordinated plan is finally adopted by an alarmed population and New York becomes a city obsessed with adapting to climate change. It clearly needs to.

Her other chapters look at more obviously and immediately vulnerable places. In the Arctic she examines the current experience of the Inuit in an area of Canada and in Greenland. Change is well under way as sea ice diminishes and permafrost melts. It brings with it not only the physical challenges to the Inuit ways but also severe cultural threats. In Greenland as the ice melts there’s the promise of wealth from resource extraction, and the ambiguities that come with it. Bangladesh is skilled in adaptation to change and experienced in flood management, but by 2050 with almost 25 per cent of the country under water as a result of rising seas and increasing tropical cyclones, accompanied by the slow and deadly seepage of saline water into wells and fields, Bangladesh will be in serious trouble. Millions of villagers will have to move to the city, and many are likely to cross illegally into India hoping to find work.

The value of Cullen’s book is that by focusing on specific places, and by talking with scientists who are devoting full attention to the problems climate change poses for those places, she brings the reader close up to inescapable realities. The details are spelt out. Moreover she does this by a lively narrative of her discussions with the scientists closely involved. Her book is not a dry account of scientific papers but a picture of the people working to understand, predict and prepare for what is in waiting for the populations in the areas she discusses. It’s a reminder too of the number and variety of people who now work on climate change-related issues.

The book recognises the adaptation capabilities being shown by some of the populations already affected by climate changes. It is with some reluctance that it acknowledges the possibility of defeat if high emission levels continue. They don’t need to continue, of course, but that is in the hands of policy makers. Cullen in conclusion examines two words in use in the science. One is unequivocal, used to describe the warming of the climate system. The other is irreversible, used to describe uncertain but all too possible eventualities. She uses the cutting down of the last tree on Easter Island, as imagined so vividly by Jared Diamond in his book Collapse, as an analogy for irreversibility. Unfortunately as yet the two words are not powerful enough in policy circles to shift the forecast for the future.

[More at: Fishpond (NZ), Amazon.com, Book Depository (UK, free shipping worldwide).]