Laying out the book in this way makes for a logical progression of ideas—and a fair bit of suspense. In chapter one at one degree Celsius, for example, Lynas describes a world with an annually ice-free Arctic Ocean. In the next chapter, as the two-degree-Celsius line is approached, Lynas warns that southern China can expect more flooding; the oceanic time lag means that it may take much longer for the rain-bearing summer monsoon to reach the drought-stricken north. That, too, is certainly plausible, based on the studies he cites.
A centimenter rise in sea level is well within the conservative IPCC projections, even for temperature increases of less than four degrees Celsius. Furthermore, published research raises the likelihood of a significant loss of ice sheets at lower temperatures, and Lynas could have claimed certainty of a disappearing Greenland ice sheet in an earlier chapter. To be sure, Lynas does take a rather uncritical view of the scientific literature. For example, he highlights the purported evidence from a Nature paper of a slowdown in the North Atlantic Ocean circulation. Does this constitute alarmism?
Is the future really so frightening, or does Six Degrees actually teach us as scientists that we are too provocative in the way we write our scientific papers? But I do think that all environmental scientists—including the conservation biologists who are likely to be reading this review—ought to read this book and ask themselves the same question.
The answer is rather important. To be caught without shelter would be to die. The possible locations of climate 'refuges'--areas remaining relatively friendly to human survival--are considered. So are the dual survival strategies of 'isolationist survivalism'--possible in, say, the mountains of Wyoming, but few today possess the necessary skills and knowledge to pursue it successfully--and 'stockpiling'--the main alternative in non-wilderness areas.
For the 6 C world, little modeling work had been done as of the writing of Six Degrees. Lynas discusses two such analogues, both much deeper in the past: The world of the Cretaceous period to 65 million years ago was very different from the present. The continents were far from their present positions--South America and Africa were still splitting apart from one another.
There was massive and long-continued volcanic activity. Seas were about meters higher, dividing present North America into three separate islands. Even the sun was different--significantly fainter than today. But this cooling influence was offset by CO2 levels estimated to have been in the range of 1, to 1, ppm, enough to keep the planet very warm indeed. Evidence puts the temperatures in the tropical Atlantic--then about as wide as today's Mediterannean--at a startling 42 C Life seems to have thrived--though present-day life would find Cretaceaous conditions not so much to its liking.
Weather apparently was challenging: Rainfall rates in the flooded interior of North America seem to have reached 4, millimeters a year--roughly 13 feet! Abundant life implies a carbon cycle active enough to match the enlivened hydrology. Plentiful organic remains meant that much carbon was sequestered, even as the intense vulcanism released massive quantities of carbon back into the atmosphere. Ironically, we are now de -sequestering Cretaceous carbon in the form of coal and oil--in fact, at a rate a million times faster than that at which it was laid dow: As in later eras, Cretaceous warmth led to ocean stratification and anoxia; evidence shows many warm 'spikes' accompanied by such anoxic episodes.
One of the most marked in the whole fossil record actually occurred even earlier, however million years ago, during the Jurassic era. Back then, a 1, ppm CO2 spike induced a 6 C rise in global mean temperature, creating "the most severe marine extinction event [in] million years. But the most severe extinction event overall belongs, not to the Jurassic, but to the end of the Permian period, million years ago.
Fossil deposits from sites around the world show an abrupt extinction from this time, accompanied by abrupt drying and erosion. Carbon and oxygen isotope ratios both shift at the same boundary; the former shows disruption of the carbon cycle, while the latter shows an abrupt warming of about 6 degrees. And the "Permian wipeout" was fast.
From geological evidence found in Antarctica, the transition may have occurred over a mere 10, years--similar to the timescale of the PETM. In the Chinese rocks forming the "geological gold standard for the end-Permian," the transitional strata occupy just 12 millimeters. The results of this spike were spectacularly horrible. The sequence of events is thought to have looked something like this: CO 2 then accumulated to four times today's levels, creating long-lived warming and inducing feedbacks similar to those discussed in previous chapters: The anoxic oceans warmed ever faster--surface water, made salty and dense through intense evaporation, began increasingly to sink, carrying its heat to the depths.
Hot seas fueled 'hypercanes'--tropical cyclones dwarfing today's hurricanes in ferocity and longevity--another challenge to an already stressed biosphere. But this was just the prelude. A plume of magma erupted through the Earth's crust in Siberia, eventually piling up layers of volcanic basalt rock "many hundreds of feet thick, over an area larger than western Europe.
Explosive methane releases followed. A modern example of a similar process occurred August 12, , at Lake Nyos in Cameroon, when carbon dioxide-saturated bottom waters, randomly disturbed, began to rise.
As the water pressure decreased with depth, the carbon dioxide 'fizzed' out of solution, forming an ever-increasing cloud of bubbles which entrained rising lake water. The result was a eruptive 'fountain' erupting meters above the lake surface. The resulting cloud of concentrated CO2, tragically, asphyxiated 1, people. The same dynamics would have been at work in the methane-saturated waters of the end-Permian, though on a much larger scale.
But while sufficiently concentrated carbon dioxide can asphyxiate, methane, concentrated enough, can explode. That is the principle of the modern "fuel-air explosive," or FAE. But those ancient methane clouds could have been much bigger than for instance the FAE deployed against the Taliban redoubt at Tora Bora. Chemical engineer Gregory Ryskin calculated that a major oceanic methane eruption "would liberate energy equivalent to megatonnes of TNT, around 10, times greater than than the world's stockpile of nuclear weapons. Presumably 10 8 was intended, not ' But other possible 'kill mechanisms' may have been active.
One possibility is that hydrogen sulfide gas may have been released in lethal concentrations. As with the Lake Nyos CO2 eruption, there is a small-scale modern example of this: Ozone depletion may also have boosted damaging ultraviolet levels--by a factor of seven, according to one study. For perspective, 50 million years ago the evolution of most modern placental mammals had just barely begun.
Some aspects of the Permian wipeout can't be replicated at present, fortunately. But biodiversity is already under threat from non-climate anthropogenic factors. Another 'great dying' seems to be in progress. And carbon emission rates are far higher than anything seen in the past, suggesting greater rates of persistent climate change to follow. Methane hydrate and hydrogen sulfide release still seem to be real possibilities--even today there are periodic hydrogen sulfide 'belches' off the Namibean coast which hint at the possibility of wider releases in a warming climate.
I myself have crawled down an Andean mountain in a state of delirious semiconsciousness when the easiest thing by far would have been to lie back and let go, but the survival instinct was too strong Even given the most dramatic rates of warming imaginable, somewhere, surely, it will be still be possible to raise crops And yet, somehow, that is scarce consolation given the torments that may lie in store. To me the moral path lies not in passively accepting our destructive role, but in actively resisting [ecocide.
The final chapter changes tack. Having dealt with the range of disasters facing humanity, Lynas turns his sights on possible human responses to climate change. For this is no mere doom-and-gloom treatise.
Despite the chapter's introductory list of things for which it was probably already too late in see the summary Hub, Choosing Our Future , for details--Lynas sees ample scope for action and for hope:. My conclusion in this book This is an urgent timetable, but not an impossible one. It seems to me that the dire situation that we find ourselves in argues no for fatalism, but for radicalism. After a consideration of uncertainties, the author sets forth the rationale for avoiding a warming of 2 C: If 2 C were to lead to the massive Amazonian die-back discussed in Two Degrees , carbon feedbacks could lead to an additional ppm of CO2 in the atmosphere, and an additional 1.
But that might invoke rapid permafrost melt which would take us to 5 C, and that could lead to methane hydrate releases good for another degree of warming.
In summary, 2 C could perhaps lead inexorably to 6 C. From this sobering table the author proceeds to strategy--in particular, the concept of 'contraction and convergence. Developed countries--the biggest historical emitters--would 'contract' emissions the most, so that emissions would 'converge' on equitable shared per capita emissions. As Lynas puts it, "The poor would get equality, while all including the rich would get survival. The difficulties in implementing carbon mitigation are then considered.
First is the practical difficulty that fossil fuels provide great benefits, and are deeply entwined throughout our economies. Second is the penchant for denial, which the author sees as running very deep indeed:. Schoolchildren are taught--and Nobel Prize-winning economics professors apparently still believe--that Earth-provided resources, from iron ore to fisheries, come into the category of "free goods," appearing as if by magic at the start of the economic process.
After a brief digression on the subject of 'peak oil,' which "will not save us," an important and extended discussion of the concept of 'stabilization wedges' concludes the book. This idea, proposed by Princeton University scholars Robert Socolow and Scott Pacala, broke down proven mitigation strategies by the resources needed to reduce emissions by one billion tonnes of carbon by Each such billion tonnes counted for one wedge; eight wedges are needed to stabilize our carbon emissions.
The discussion is useful in illuminating the problems of scale we face. For example, when Six Degrees was written:. A wedge of solar photovoltaic electricity generation would need a fold increase Lynas describes this as "daunting. Wind power has risen 5-fold between and , so that we now need to increase wind by a factor of ten; solar PV is up 7-fold, which reduces the factor required from to One confusion arises because in , Lynas would not have had data on renewables available. It appears he was probably working with or data, which was likely the most recent available figures.
That would make the 'stabilization wedge' date 49 years in the future--though that number is still less realistic, as solar prices and growth rates have been accelerating still more rapidly than has been the case for wind. For example, a new study estimates that installation rates will rise to over 70 GW by Arithmetic says that if that is true, we would, in , have nearly GW installed PV, and would reach one stabilization wedge by about or so.
A report by the commercial solar energy analytic firm NPD Solarbuzz projects global solar PV installation rates to reach GW annually by , and cumulative global capacity to reach GW in the same year.
That would bring one stabilization wedge of solar PV online by On the other hand, Lynas points out, stabilization by is not enough--not if we wish to safely skirt the dangers of carbon feedbacks. To miss 2 C, we would need another 4 or 5 wedges. That brings up the contentious issue of lifestyle change in the wealthy world. It's a 'hard sell. Moreover, lifestyles have been changing in the developing world toward increased carbon intensity.
Six Degrees: Our Future on a Hotter Planet ( pages), ISBN 7 is a ( in USA) non-fiction book by author Mark Lynas about global. Six Degrees: Our Future on a Hotter Planet [Mark Lynas] on uzotoqadoh.tk *FREE * shipping on qualifying offers. Possibly the most graphic treatment of global.
Western diet and consumerism has become more and more normative around the world. As currently implemented, it is very carbon-intensive.
All the evidence shows that people who do not drive, do not fly on planes, do shop locally, do grow their own food, and do get to know other members of their community have a much higher quality of life than their compatriots who remain addicted to high-fossil-fuel-consuming lifestyles.
One hopes that the author's optimism is justified. But it is characteristic: Lynas is not peddling doom and gloom. There is an old story about another visit to Hell: Around it the damned sat starving, staring at food which they could not eat--their arms were all enclosed in splints, which made it impossible for them to bend their elbows and thus reach their mouths. A fiendish punishment, to which they reacted with all the anger and dejection one might expect.
But a tour of Heaven followed. Surprisingly, the same basics dominated: But in Heaven, hilarity and good fellowship reigned: So Lynas's vision of possible Earthly infernos ends with a vision of heaven on earth. Humans are often selfish, short-sighted and greedy, of course. But it's true, too, that our success so far on this Earth has been built upon ever-more intricate structures of cooperation. That potential, too, is part of our 'nature. Lynas's book sets forth in great detail the future now being ushered in by short-sighted greed, so perhaps it is only fitting that at least a brief look at a future in which rational cooperation shapes events.
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Second is the penchant for denial, which the author sees as running very deep indeed: They are just machines. The sea's devoured the land. Climate systems are very complex and trying to present them, and potential events within and affecting them, in the linear form of words, rather than, say, a series of animated 3-D flowcharts and diagrams, is inevitably a challenge. At some point the warming of ocean temperatures may cause the release of methane hydrate a greenhouse gas that is currently trapped at the bottom of the ocean under the load of high water pressure.
I'm working on my fiction project, too, though it's slow. I think I understand why you switch between music and climate. After delving that deeply into the horrific implications of the path we're on, a course of soothing music might be enough to keep you sane. Thanks for your hard work. BTW, the series of short stories I'd told you that I started recently, which takes place in the climate effects at the end of the century, will soon have a third installment.
I suspect that some more of what you wrote about here will end up in the fiction. That is extremely kind! Of course you are welcome to pass my stuff around if you feel it would be helpful in any way. It's a very flattering thought. But don't be hard on Ric--when I posted to RealClimate that I had this Hub up, I specifically mentioned that I'd appreciate any editorial input readers there might provide. Can't complain that he took me at my word--and I'm really grateful to have those typos gone. That sort of thing really disfigures a Hub, in my opinion, so I'm truly grateful to him. Speaking of Realclimate, it is a great resource for those who are up for a somewhat technical ongoing discussion of climate-related issues, with a heavy emphasis on the science:.
I'm clicking thru to buy the book on Amazon.
May end up under a friend's or family member's Xmas tree after I read it-- my way of spreading the word. And one of them just wanted to point out typos! It's an absurd world we live in, isn't it? Maybe I'll print out copies of some of your articles to hand out to my inner circle during the holidays. I assume you won't mind. Yes, a lot of people approach global warming from the perspective of daily temperature variation: Well of course 2 C would take 63 F to about Shift the monthly mean from 32 F to Maybe better for string beans, say, but maybe not so good for proper dormancy for a number of tree crops.
At the other extreme, 98 F becomes But that's not the biggest factor, either: That concept is kind of elusive, I admit. Thank you for the summary. Typos you can search for: Pretty incredible and scary rundown of the effects of global warming by degree. Thanks for writing this well written Hub Doc. People need to know what we are gambling with as we continue to dump carbon dioxide and methane into our atmosphere.
Two Degrees The two-degree world is less familiar, but not yet completely strange. Three Degrees In this chapter, climate regimes we might term 'sort of safe' are left behind. As Lynas puts it: Four Degrees In a 4 degree world, food production continues to decline as the world is increasingly transformed. Five Degrees Lynas description of the five degree world is as stark as it is brief: On balance, Lynas both strategies unlikely to succeed, except in infrequent instances. Complete human extinction strikes Lynas as unlikely due to humanity's: