Cassandra has moved. Ugo Bardi publishes now on a new site called "The Seneca Effect."

Tuesday, September 2, 2014

Cli-fi: ten assorted doomsday scenarios

Image created by Robert A. Rohde / Global Warming Art.

In fiction, it is allowed to extrapolate the consequences of normal phenomena to their extreme forms and to examine events that could happen, no matter how they are perceived as unlikely. Hence, the interest in "climate fiction" ("cli-fi") as a way to explore the possible consequences of climate change in situations much more extreme than those of the usually sanitized scenarios presented by scientists.

It seems that, so far, only a few of the many possible climate related catastrophes have been explored in detail in movies and novels. So, I have prepared here a list of ten apocalyptic scenarios, all related to climate change (of course, many more can be conceived). "Scenarios" and "fiction" are closely related concepts, except that the latter doesn't necessarily have to follow the laws of physics. In this case, none of these scenarios is physically impossible; but they are stretched a bit (a lot) for increased fictional dramatic effects.  The list may serve as a source of inspiration for those of us who are trying their hand at writing cli-fi novels. The scenarios are arranged in an approximate order of increasingly catastrophic events. 

1.  "The Great Coal Flame" (or "Saddam squared"). A giant coal fire which can't be extinguished. We all know how, in 1991, the Iraqi troops retreating from Kuwait dynamited some 700 oil wells, generating giant fires. The damage generated was not terribly catastrophic and the fires could be extinguished in less than one year, choking them at the mouth of the wells. However, we can think of something more difficult to stop if we imagine that the fire could affect a large coal deposit. There already exist underground coal fires which have burned for centuries and seem to be impossible to extinguish. Let's imagine something much bigger, maybe as the result of a tactical nuke landing by mistake (or purposefully) on a major coal mine. The result would be a giant fire covering an enormous area; it would be probably much more difficult to  extinguish than the localized oil well fires of Kuwait in 1991. Maybe this would not be a global disaster but, already now, uncontrolled coal fires account for about 3% of the world's CO2 emissions; if a major coal mine were to catch fire, the resulting disaster could considerably accelerate the process of climate change. To say nothing of the damage generated in terms of ashes, sulfur oxides, mercury, and other poisonous chemicals.

2."Super-Calving." or "Heinrich's return". The rapid collapse into the sea of large amounts of ice. "Calving" is a well known phenomenon in which large masses of ice detach themselves from ice shelves and create icebergs. Normally, the process causes no damage to humans (except for special cases, such as for the "Titanic"). But imagine that very large chunks of ice were released at a much faster rate than the present one. It has happened in the remote past in episodes known as "Heinrich's events" described a "Armadas of icebergs crossing the North Atlantic". The process could disrupt navigation in areas near large ice sheets, such as near Greenland and it could also generate giant waves - not tsunamis, but large enough to cause damage at considerable distances. Then, the presence of large amounts of ice floating in the ocean would have significant effects on climate and on the oceanic thermohaline circulation. The combination of these phenomena would disrupt commerce and transportation in a vital area for the world's economy. Not really a worldwide disaster, but a big disaster anyway.

3."Hyperstorms" Giant storms wreaking disasters. An increase in the frequency and the size of hurricanes is expected to be a consequence of climate change. In some conditions, hurricanes could become truly enormous and in this case they would take the name of "hypercanes", continent-size super-storms which reach the stratosphere, with side effects such as destroying the protective ozone layer. Because of this effect, it has been speculated that some of the past mega-extinctions were due to hypercanes. It is believed that sea surface temperatures high enough to create hypercanes can be generated only by exceptional circumstances, such as by asteroidal impacts. However, it is not impossible that a combination of factors related to global warming could generate larger and larger storms. Now, already in the present conditions, hurricanes are a major destructive force on human-built structures, imagine something much bigger and even more destructive..... The damage would be mostly local, unless we manage to unchain a true hyperncane which would create worldwide havoc by destroying the world's ozone layer.

4. "The great ring of ice disaster". The melting of the Northern ice sheets generates earthquakes and tsunamis. The "ring of ice" is a region which encompasses a number of geological faults in the Northern Hemisphere. This is already a volcanic active region, but the melting and the Greenland ice sheet would generate further instabilities. Greenland "floats" over the underlying semi-fluid mantle and would rise up when freed of the mass of ice that covers it (this is called "isostatic rebound"). The result would be the destabilization of the geological faults in the area: an increase in volcanism, earthquakes, large coastal landslides, and perhaps the sudden release of large amounts of methane from frozen hydrates. The most disastrous results would be Atlantic tsunamis, a phenomenon which so far has been very rare, but that would be enhanced and made more common by climate change. Tsunamis originating in Greenland could hit especially hard Scotland, Norway, and Ireland, but also the Northwestern continental European coast (Holland, in particular) disrupting or destroying an industrial and commercial hub fundamental for the whole Europe. That would surely have worldwide repercussions.

5. "The Big Freeze" (or: "the Younger Dryas reloaded"). A rapid cooling, something of the order of −5 °C (23 °F) of the Northern hemisphere. The tumbling into the ocean of the Greenland ice sheet could shut down the North-Atlantic thermoaline circulation. As we have seen in the movie "The day after tomorrow," that would generate a rapid cooling of the Northern hemisphere. It is believed that something similar has already occurred during the period called the "Younger Dryas", around 12,000 years ago; probably  caused by the sudden release into the Atlantic of the cold water of a lake ("Lake Agassiz") when the ice dam that kept it locked in place gave way. (yes, it is the plot of the second film of "the ice age" series, the one titled "The Meltdown"). In the case of the Younger Dryas, the freeze appears to have taken place in a few years. Imagine if something similar were to happen today: the consequences would be, well, unimaginable, even if we were to assume that they would affect only the Northern Hemisphere.

6. "The great sea onrush" The sea rise generated by the rapid melting of the Greenland and West Antarctic ice sheets wipes out most of the coastal cities and infrastructures. The disappearance of the ice sheets of Greenland and of Antarctica is not so much a hypothesis as a virtual certainty, given the present trends. That would lead to a sea level rise of some 7 meters (24 feet) from Greenland alone, plus about 3 meters from West Antarctica, and further contribution from the slower melting of other ice sheets. However, it is normally believed that this event would unfold in centuries or millennia and that humans would have time to adapt (perhaps). After all, as it is often said, what is affected by the sea rise "is only real estate". But let's imagine that the process were much, much faster - taking place in a few decades or even less at least for one of the two most unstable ice sheets in the world: Greenland and West Antarctica. You would not see the onrush of giant waves submerging coastal cities, as in the "2012" movie, but the sea rise would still be so fast that there would be no time to build levees or to relocate buildings and facilities inland. The result would be a frantic rush inland, while vital industrial and transportation infrastructure would have to be abandoned. A true global disaster.

7. "Tickling the tail of the dragon" (or: "Shooting yourself with the clatrhate gun"). A giant, human caused methane release and the consequent rapid rise in temperature. Let's imagine that some well intentioned people try to solve the energy crisis by extracting methane from buried hydrates (or clathrates) at the bottom of the ocean. Now, imagine that by drilling inside these clathrate reservoirs triggers a self-reinforcing release phenomenon. Just like BP didn't know how to stop the Macondo well leakage, the companies drilling - say - in the Arctic ocean, would discover that they don't know how to plug the hole they have drilled and that, even if they could, more and more holes are appearing by themselves. The result is a massive release of methane in the atmosphere, a greenhouse gas much more powerful than carbon dioxide. As a consequence, the "worst case" IPCC scenarios unfold in a few years instead of a century. The results? Well, possibly all the four previous scenarios: collapse of the ice sheets, oceanic thermohaline shutdown and all the dire consequences. But also extensive climate disruption and the desertification of temperate region. You wouldn't speak anymore of "drought in California" for the same reasons why you don't normally speak of "drought in the Sahara desert". California would become like the Sahara desert (and not just California). Totally global disaster.

8. "Goldilock's disasters" or "The great climate rebound". Geoengineering can backfire. We can imagine multiple disasters arising from well intentioned but ill conceived efforts to reduce global warming. Spraying particulate in the upper atmosphere, or maybe putting giant mirrors in orbit, would cool the earth, but we don't know how it would affect the weather patterns. For instance, it could weaken the Indian Ocean monsoon and condemn at least a billion of people to starvation. Or, one could go too far in the opposite direction and cool the planet too much, (too much of a good thing) with effects similar to those of a nuclear winter. Finally, imagine that a major economic crisis defunds the geoengineering effort. Or, imagine that a major spin campaign convinces people that it was a hoax or useless (that's possibly the most realistic element of this scenario). Then, as the sunscreens fall, the earth returns to warming with a vengeance, as it would do after a nuclear winter and temperatures shot up so fast that, before screening can be resumed, it is too late. And that's truly global!

9. "The world as a giant gas chamber". What if CO2 turns out to be not so harmless as it is commonly believed? CO2 is often defined as "plant food" and it is believed that it cannot negatively affect human health until it reaches concentrations over at least 10 times the present values. However, it is also true that our species evolved in conditions of CO2 atmospheric concentrations below 300 ppm and that the present concentrations of 400 ppm have never been experienced by our ancestors. As the concentration of atmospheric CO2 keeps building up, we could reach concentrations four of five times larger than those which have been the rule for the past million years or so. CO2 is a reactive molecule which, among other things, would affect the blood pH and it has been argued that concentrations over 425 ppm would already have negative effects on human health; to say nothing of much higher values. So, if we discover that we have transformed the planet into a giant gas chamber, what would we do? 

10 "Venus, the ultimate disaster."  Temperatures could go up high enough to kill everything. The "Venus Scenario" is an extreme version of the "runaway greenhouse" effect. As temperatures go up, more and more water vapor is pumped into the atmosphere. Since water vapor is a greenhouse gas, it causes further warming of the atmosphere. At its extreme limit, the process could self-reinforce to the point that the oceans would completely evaporate. Temperatures could become so high that carbonates in the crust would be decomposed and that would create a dense atmosphere saturated with CO2. Add some sulfuric acid generated by volcanoes and you have transformed Earth into something very similar to Venus. Temperatures would reach several hundred degrees C at the surface; no liquid water, no life. Right now, the solar radiation arriving on the earth is believed to be not high enough to generate the kind of feedback that would transform earth into a twin of Venus. But there are always uncertainties in these calculations and the "Venus scenario" cannot be completely ruled out. The only escape from the Venus catastrophe would be leaving Earth for another planet, supposing that humans were able to build spaceships early enough. This is, clearly, the ultimate catastrophe: the sterilization of the whole planet.

It is fiction, it is only fiction, but........

See also another list of climate disasters. Also the source of the above image


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