(This is part 2 in the “Crisis and Inertia” series.)
Surprisingly many people seem to be under the impression that climate change won’t really affect them. “Sure, it will get a little bit warmer, but that’s what air conditioners are for, and sea level rise doesn’t really affect me because I don’t live on the coast and it is slow anyway.” Something like that appears to be general idea.
Unfortunately, that idea is wrong. Very wrong. Climate change will have much bigger effects than air conditioners and coastal protection can fix. The exact nature of those effects is uncertain, however, but there is much we do know about Earth’s climates and how they will change.
The main reason why climate predictions are uncertain is because climate is complicated. A good model of wind systems takes years to build and a supercomputer to run, and that’s just a model of wind. A rise in temperature influences wind systems, wind systems influence ocean currents, both influence temperatures (leading to a feedback loop, which may be positive, negative, or both in different places and circumstances), all of these influence precipitation patterns, which influence temperature, and wind and temperature also influence evaporation, which influences precipitation, and so forth. In other words, climate is a complex system of connections and feedback loops between various systems that are hideously complex themselves. We can model parts thereof, but no one has managed to put all of that in a single model that is sufficiently detailed, and perhaps, we’ll never be able to – the level of complexity is too great.1 The consequence hereof is that climate predictions are always – and necessarily – based on simplified models that take only some (sub-) systems into account and ignore many of the feedback loops and other complexities.
In addition to trying to model climate, studying climates of the past can also be a valuable source of information. However, nothing in the past resembles the current climate situation in all relevant dimensions. For example, the historical event that appears to be most similar is the Last Interglacial (LIG), approximately 129 to 116 thousand years ago. The period started with a simultaneous sharp rise in CO₂ and temperature. CO₂ rose from around 200 ppm to a peak value close to 290 ppm and global average temperature rose from 6 degrees Celsius below the current average to 2 degrees higher (so a total increase of 8ºC). In contrast to the current situation, it wasn’t the rise in CO₂ that was the main cause of warming, however, and there was, therefore, (probably) no significant ocean acidification. For comparison, CO₂ levels are now well over 400 ppm, which is the highest level in a very long time, and this is having other effects besides warming. There are earlier periods in Earth history with similar or even higher CO₂ levels, but they differed so much in various other respects that a comparison cannot really tell us anything about Earth’s near future.
Nevertheless, even if historical data cannot replace models it is essential to test and refine models. If a model doesn’t accurately “predict” historical climate change based on historical data, then it is not a good model. Furthermore, if historical data for relatively similar climate events deviates significantly from what a climate model predicts for Earth’s future, then that is reason to wonder what explains that difference – it may be a difference in the two situations, but it may also be a flaw in the model. For example, very recently Hubertus Fischer and 59 co-authors concluded in a review article published in Nature Geoscience2 that a comparison of historical evidence (“palaeo data”) and model estimates “implies that long-term sea-level rise and regional and global warming may in the long run be significantly more severe than state-of-the-art climate models project” (482).
If Fischer and his 59 co-authors are right, then current climate models significantly underestimate the extent of climate change. There is a very different reason to believe that that may very well be the case indeed. Last year, David Wallace-Wells published an article “The Uninhabitable Earth” in New York Magazine describing some of the possible – or perhaps even probable – effects of climate change. He was almost immediately accused of “alarmism”, and several so-called “climate skeptics” denounced his article as “disaster porn” or something similar. The article certainly is sensationalist, but I’m not sure whether it is really alarmist. Nevertheless, that accusation is important, because it appears to be the case that there is nothing a serious climate scientist fear as much as being accused of alarmism. Good science is modest in its conclusions, but the combined effect of this appropriate modesty and the fear of alarmism – as Keynyn Brysse and colleagues have shown3 – is that climate predictions tend to err in the opposite direction. Brysse et al. call this “erring on the side of least drama” – what it means is that climate models systematically underestimate the extent of climate change.
So these are the problems we need to take into account. There is considerable uncertainty in climate prediction, which is due to the complexity of climate systems and the impossibility of combining all relevant aspects of climate in a single model. Because of this, the real effects of climate change will deviate from what the models predict. Even if on a global level such deviations turn out to be minor, there may be very significant differences on a regional level. Furthermore, for sociological reasons, climate scientists have been overly cautious in their predictions, which has been confirmed by comparing predictions with actual climate change over the past decades, and historical data also suggests that real effects will be more severe than the models predict. In other words, climate science does not and cannot accurately predict all the details of future climates, but where it goes wrong it is more likely to underestimate the severity of effects than to overestimate them. So, with this caveat, let’s have a look at what we can expect (but don’t expect completeness).4
Most people know that sea levels are rising. That rise is very slow (albeit faster than most models predicted), but will probably gradually increase. By the end of the current century the average sea level rise could be anywhere between 30 cm and 2.5 meters (or even more). After that, sea levels will continue to rise. By how much exactly is unknown, but the melting of the Greenland ice sheet alone (which may be unavoidable) will add more than 7 meters. Glacier melting, melting of parts of the Antarctic ice sheet, and expansion of warming sea water will add more. Because this process is very slow, it may never seem like an acute problem and is easily ignored by most people, but for low-lying areas even a small rise in sea levels is a big problem – and many low-lying areas are densely populated. Bangladesh is an obvious example, but there are also densely populated low-lying areas in industrialized, rich countries that are threatened by sea level rise.
If higher sea levels would be the whole problem, we could just build higher dams to protect coastal areas, but that is unlikely to be sufficient – and it would be much too expensive anyway, especially in poor countries like Bangladesh or Pacific island nations that will be drowned completely. Low air pressure above sea leads to a local water level rise – in a sense, the water is sucked upwards a little bit by the low pressure. The lower the pressure, the higher the rise. Low pressure areas above tropical waters form into tropical storms. If they stay long above warm water, these develop into hurricanes or typhoons, which have very low pressures in their centers (the eye of the storm), and therefore locally increase the water level by a significant amount. This is called a “storm surge”. The warmer the sea – and climate change is warming up the oceans – the stronger and more frequent tropical storms, hurricanes, and typhoons. And therefore, the warmer the sea, the more frequent and severe flooding of coastal areas will be. Building dams that do not just deal with the rising sea level itself, but with the increasing intensity and frequency of storm surges as well is not a feasible option. And even if it was, these dams would have to be heightened continuously because sea levels will keep rising for many centuries to come. Soon enough, the land protected by a hypothetical dam would be below sea level, and a small defect or unusually strong storm would lead to a devastating flood.
We cannot prevent rising sea levels. Most climate scientists believe that it is unlikely that we’ll be able to keep global warming below 2ºC by 2100,5 and those 2 degrees will already lead to a sea level rise of several meters on the long run. We can temporarily protect some coastal areas, but we cannot continue building higher and higher sea walls – one after the other, low-lying coastal areas will have to be given up. A substantial part of Bangladesh will be lost to the sea before the end of the century and there is nothing we can do about that. (Or at least, not any more.) Which areas exactly will be lost to the sea, and when exactly (or in what order) is hard to predict, but what is certain is that tens (or even hundreds) of millions of people will lose their land and houses due to sea level rise before the end of the century, and many hundreds of millions will suffer the same fate on the longer run.
On a side note – there is a weird fixation in climate debates on the year 2100, as if all change will stop by then. This is nonsense, of course. In fact, most of the climate change, and especially the most dramatic changes will occur after that date. Many processes – like the melting of ice caps – are very slow and thus take a very long time (centuries or even millennia) to fully develop their effects. And many effects of climate change will last thousands of years – we are not changing global climates for the near future, but on the long run. History is illustrative in this respect. I already mentioned above that the Last Interglacial saw a CO₂ increase from approximately 200 ppm to 290 ppm. After that, CO₂ slowly decreased again, but the decrease to the previous level of 200 ppm took 100,000 years. The CO₂ we’re putting in the atmosphere now will stay there for tens of thousands of years. Earth’s climate will not return to what we have gotten used to for a similarly long period (and possibly even ever). Even stability – a new equilibrium – is in the very distant future. For thousands or even tens of thousands of years climate will continue to change.
Let’s return to the oceans. It should be obvious that sea level rise is a serious problem. It’s probably not the most serious ocean-related problem, however. That dubious honor goes to acidification. CO₂ dissolves in sea water to form carbonic acid. The more CO₂ in the atmosphere, the more carbonic acid in the ocean. And as you can probably imagine, acid is not good for the things that live in the oceans. Acid dissolves the shells of mollusks and the skeletons of corals, for example, and some kinds of plankton – the base of the oceanic food chain – don’t thrive in more acidic water either. Corals are especially badly affected as they are threatened by sea level rise as well. Corals grow close to the water surface. If the ocean rises slowly, or the reef they are growing on sinks slowly, they can keep up, but if the water is more acidic and/or if the the sea level rise is too fast they cannot and they die. Because coral reefs are hit by both sea level rise and acidification (as well as pollution and further problems) the number of healthy reefs continues to drop. It may very well be the case that before the end of the century – and possibly even earlier – most or even all coral reefs on Earth are dead. Coral reefs are among the richest ecosystems in the oceans – one quarter of marine species are related to coral reefs – and as corals die almost everything else that lives in the reef dies with them, leaving nothing but slimy algae.
Coral reefs aren’t the only marine ecosystems that are badly affected by climate change and ocean acidification, and there is, moreover, a further problem for the oceans: declining oxygen. Mostly due to the abundance of artificial nutrients (from fertilizers mainly) in coastal waters, but also due to warming, there are more and more areas in the sea where oxygen levels drop (but usually only periodically), sometimes below a level that can sustain fish and most other life forms. This occasionally leads to mass dying of fish (which then wash up on the shore), but it also has other effects. Structurally deoxygenated areas turn into dead zones. The only organisms that thrive there are bacteria that produce poisonous hydrogen-sulfide (the gas that smells of rotten eggs).
It is hardly an exaggeration to say that death is spreading throughout the oceans. I’m not saying that all marine life will become extinct, but very many marine ecosystems are badly affected. Coral reefs are dying, coastal areas are suffering from deoxygenation, the bottom level of the marine food chain is threatened by acidification, sea floors are destroyed by beam trawling, and overfishing further reduces fish stocks. Probably, life in the oceans will remain, but soon it won’t be able to feed us any more. Hundreds of millions of people depend on food from the sea, and most of that food comes from coral reefs and shallow coastal seas – it comes from the parts of the oceans that are most severely affected and that are already dying.
Changing wind systems and changing sea water temperatures lead to changing weather systems. In the temperate zone the weather becomes more erratic, unpredictable, and extreme – heat waves, big storms, downpours leading to floods, unusually cold winters, and so forth. Other zones will experience different effects. The subtropics will mostly get drier, for example. This process is already well underway, and is often mentioned as one of the causes of (civil) war and unrest in the Middle East (Syria, particularly). Drought is a serious problem and is extremely sensitive to changes in the Earth’s average temperature. According to a study by Chang-Eu Park and others6 if global warming is kept in the 1.5ºC to 3.5ºC range, aridification (severe drying) will affect between 24% and 32% of land surface and between 18% and 24% of the world population. That means that more than a billion people will be affected by drought. (On the other hand, many models expect that the Sahara will become green, although this will be tree-less savanna or steppe with frequent wildfires, and thus hardly new farmland.)
Heat is another problem, especially in combination with humidity. Traditionally this was measured by putting a thermometer in a wet cloth and swinging that above one’s head. The resulting temperature measurement is called the “wet-bulb temperature”. At 100% humidity evaporation cannot cool down the thermometer, but at lower humidities the wet-bulb temperature will be lower than the air temperature (the “dry-bulb temperature”). The table below shows the relation between air temperature (left column), humidity (top row), and wet-bulb temperature (all other cells). If the wet-bulb temperature is higher than 35ºC humans are unable to reduce body heat (fans are useless in such circumstances), and therefore, we cannot survive prolonged wet-bulb temperature of over 35ºC. But even lower wet-bulb temperatures are dangerous. I’m writing this in the middle of a heat wave (Tokyo, July 2018) with peak wet-bulb temperatures of around 31ºC. Outdoors activity in such circumstances is potentially lethal. Most of the people who are dying due to the heat are old people working on fields in the blazing sun, but last week a 6-year old kid died of the heat while playing outside. There are currently no places on Earth that have prolonged wet-bulb temperatures over 35ºC, but this is almost certainly going to change. Parts of Southwest Asia, for example, are expected to exceed this limit and thus will become uninhabitable, unless CO₂ release starts dropping substantially (and fast) very soon,7 and there are other regions that will become uninhabitable for the same reason. (Parts of China, India, and South-East Asia are among the most densely populated areas that will experience deadly heatwaves, but according to some researchers anywhere between half and three-quarters of the world population will experience extended deadly heatwaves by the end of the current century.)8
Heat is, moreover, not the only health concern. There are various diseases and disease-carrying insects that thrive under hotter conditions. The Lancet published a long review and commission report last year documenting various expected effects of global warming and pollution on health,9 but I will not attempt to summarize these here.10
The closer to the poles, the greater the extent of warming expected in all models – the average temperature in high-latitude areas has been rising twice as fast as the global average in the past decades. That may seem nice for Canada and Siberia, but when it comes to climate change, there isn’t really anything that is “nice”. There currently is about 870 gigatons of carbon in the atmosphere, mostly as part of CO₂. About twice that amount is stored – mostly in the forms of methane and CO₂ – in the permafrost.11 Some of it is stored at considerable depth, but much of it is stored in gas bubbles in ice near the surface (so-called “methane clathrates”). That ice, however, is melting. How much of that methane and CO₂ will end up in the atmosphere is presently unknown, but there is considerable risk that – unless we’re able to stop global warming soon – it will set of a feedback loop of warming, further carbon release, further warming, and so forth. And no one knows when that process would stop.12
There are several “tipping points” with regards to climate. Points beyond which certain climate-related processes suddenly take on a different form leading to rapid and severe changes. One of the most mentioned tipping points is related to the carbon stored in the permafrost. If we pass that tipping point, melting of the permafrost starts to releases so much carbon into the atmosphere that it leads to significant further warming. (And this is one of those feedback loops that climate model typically do not take into account.) We may have already passed that tipping point – or perhaps we haven’t passed it yet, and the current permafrost melting will stop at some new equilibrium before releasing massive amounts of methane and CO₂. We don’t really know actually, but all the reports about permafrost melting of the last few years suggest that there is little reason for optimism.13
The most direct problem for humans is lack of food or water due to climate-change effects. Drought will have such effects, but so will floods and various other disasters, as well as the expected collapse of the sea as a food source. An additional problem is that the insects needed for pollination of many crops and other plants are declining as well – most likely due to pesticides. In a German study it was reported that the biomass of flying insects was reduced by 75% in 27 years.14 This is a further potential cause of crop failure and food shortages in the future. There is a large literature on the relations between drought, crop failures, hunger, water shortage, migration/refugees, and violence, but not much is clear about what causes what in which circumstances exactly. Depending on other circumstances, drought can lead to migration (refugees), and perhaps also to violent conflict, but there are mediating factors and which ones make the difference is presently unknown. Clionadh Raleigh and colleagues found that food prices are an important mediating factor causing violent conflict in Africa.15 Others have pointed at historical circumstances, or various other details. Thus far, the indirect relations between climate change and violent conflict have only been studied on relatively small, regional scales, however, and it is not clear how scale-able they are. We have little experience with refugee flows that number in the tens or even hundreds of millions of people, and that are the kind of numbers we almost certainly will be dealing with by (or even before) the middle of the current century.
The Climate Crisis
It should be clear that climate change constitutes a crisis. What may not be sufficiently clear yet is how serious this crisis is and how much “force” is needed to avoid it. If global warming melts all the permafrost and all that carbon ends up in the atmosphere (and some other “positive” feedbacks kick in as well), Earth will get so hot, and Earth’s oceans so acidic, that little will survive. That would be the 6th mass extinction. Some scientists think that the 6th mass extinction is already underway, but while many animals and plants have gone extinct (and many more will follow), mass extinctions are defined as extinction of the extremely widespread organisms at the base of the food chain, and no such extinction is occurring. Hence, there is no mass extinction (or at least not one comparable to the previous five) in progress yet. Most climate scientists seem to believe that global warming will be limited – that not all carbon the permafrost will end up in the atmosphere and that some other “positive” feedbacks can be avoided as well. Assuming that their optimism is well founded, there will be no 6th mass extinction, and humans will probably survive climate change.
Whether civilization can survive climate change is a different matter, however. The combined effects of coastal flooding, drought, overheating, and secondary disasters such as crop failures and (civil) war will produce very large refugee flows, and because climate effects are rarely restricted to very small areas, these flows will cover larger and larger distances. It is difficult to put numbers on this. Many people will be unable to flee the heat, drought, floods, hunger, and/or violence and will die where they lived. Some of the stronger will try to flee. The number of people in coastal low-lands that will be affected by sea level rise this century (and as mentioned, sea level rise won’t end this century) is somewhere between a quarter of a billion and a billion; the number of people that will be affected by drought is somewhere between half a billion and a billion; the number of people that will lose their main food source (such as sea fish) for other climate-related reasons is between a quarter and half a billion; and so forth. All these numbers are very uncertain. According to some predictions, the densely populated north of India (home to half a billion people) might become either too hot or too dry, which would add another large number. There is little point in adding up these numbers – pretending more certainty than is justified – but what we can say is that it would be a very conservative guess that there will be around half a billion climate refugees by the middle of this century, and many more by the end. These people will try to move to the parts of the planet that offer a better chance of survival: the temperate zones where most of the wealthy countries are located.
In Tropic of Chaos Christian Parenti discusses the relations between climate change and violence.16 He suggests that rich nations will develop into “armed lifeboats”, trying to keep afloat by keeping out “others” (i.e. climate refugees, and everyone else who doesn’t “belong”) by means of barriers and violence. But no barriers and no amount of violence will be enough to stop refugee flows of many hundreds of millions. Parenti writes:
There is a real risk that strong states with developed economies will succumb to a politics of xenophobia, racism, police repression, surveillance, and militarism and thus transform themselves into fortress societies while the rest of the world slips into collapse. By that course, developed economies would turn into neofascist islands of relative stability in a sea of chaos. But a world in climatological collapse – marked by hunger, disease, criminality, fanaticism, and violent social breakdown – will overwhelm the armed lifeboat. Eventually, all will sink in the same morass. (p. 20)
This is already happening. Xenophobia and racism are on the rise in all wealthy countries. Surveillance and militarism are growing. Europe and the US are trying to turn themselves into fortresses by turning their southern boundaries into militarized zones of death and suffering – by letting refugees drown in the Mediterranean, by building concentration camps, fences, and walls, and so forth. And in most (if not all) wealthy countries neofascist movements are on the rise. We are well on our way to the armed lifeboat.
In his book, first published in 2011, Parenti suggested that there is an alternative. Whether there still is one seems doubtful, however. Even if we stop releasing CO₂ into the atmosphere right now, there already is so much of it that temperatures will continue to rise, that sea level rise will continue, that hurricanes and typhoons will continue getting stronger and more frequent (even more than we already have experienced in the past few years), and that several other climate changes that have already been set into motion will continue as well. Much climate change is already unavoidable. (Except, perhaps, if we would be able to take CO₂ out of the atmosphere, but we cannot do that at the necessary scale and speed, and there is no reason to believe that we will be able to do so soon – or ever, if we continue on the present path.) If we would stop releasing CO₂ soon we may be able to avoid some of the worst effects of climate change, but much of what I described above cannot be avoided any more (“much”, but not all!). Even in the best case scenario large parts of the Earth will effectively become uninhabitable and there will be hundreds of millions of refugees. On the other hand, if we don’t stop releasing CO₂ soon, we may slip into the worst-case runaway global warming scenario leading to a 6th mass extinction.
Climate change is unavoidable. There is nothing (not even a “tomato catcher” – see part 1 in this series) that can stop that. But that doesn’t necessarily mean that human civilization cannot adapt to it. The armed lifeboat strategy is not an adaptation: it will only increase suffering and chaos in the rest of the world, and the lifeboats will eventually (probably sooner rather than later) be overwhelmed. At that point only chaos will be left. Civilization cannot survive by first becoming neofascist and then collapsing into violent chaos. The armed lifeboat strategy is a recipe for a Dark Age. And in that chaos, billions will perish.
The only way for civilization to survive climate change is to adapt. It cannot do that by trying to isolate itself from the effects of climate change, which is exactly what the armed lifeboat strategy is trying to do. Civilization can only survive if the lifeboats are punctured as soon as possible – making them sink while the “sea of chaos” is still shallow and a better alternative can be constructed, making them sink while there is still time to adapt to the chaos and work out a different strategy to actually cope with and adapt to a rapidly changing world (rather than trying to ignore it). This is where inertia kicks in, of course. The wealthy countries are already set on the armed lifeboat course, and the only thing that can change their course is a force that is large enough to overcome their momentum. The question is whether there can be such a force, and – if there is a positive answer to that question – whether it would be less destructive than what it would be trying to prevent.
Can we puncture the armed lifeboat? If so, how? And what exactly would it mean to puncture the armed lifeboat? Just forcibly opening external borders won’t be enough, as all rich nations have internal, social boundaries between the rich and poor (i.e. between social classes), between ethnic groups, between “citizens” and immigrants, and so forth. But opening the borders would be a start, and it might set off the crisis needed to sink the armed lifeboat before it is too late. However, the hole must be big enough to make the lifeboat sink – if it can be patched up it will only reinforce the tendency towards neofascist repression and militarization. Whether that is possible – whether it is possible to sink the armed lifeboat before it is too late – is the key question, but that question cannot be answered while ignoring the other crises humanity is facing. So that’s where we need to turn our attention first.
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- Most likely, the level of complexity is such that accurate prediction is fundamentally impossible because immeasurably small differences in the starting conditions will lead to significantly different outcomes. This is “complexity” in the technical sense, popularly known as “chaos theory”.
- H. Fischer et al. (2018). “Palaeoclimate Constraints on the Impact of 2ºC Anthropogenic Warming and Beyond”, Nature Geoscience 11, July 2018: 474-485.
- Keynyn Brysse, Naomi Oreskes, Jessica O’Reilly, and Michael Oppenheimer (2013). “Climate Change Prediction: Erring on the Side of Least Drama”, Global Environmental Change 23: 327-337.
- Possibly the most complete and up-to-date, freely accessible overview of the effects of climate change is the Wikipedia page “Effects of Global Warming”.
- See, for example, Adrian E. Rafttery, Alec Zimmer, Dargan M.W. Frierson, Richard Startz, and Peiran Liu (2017). “Less than 2ºC Warming by 2100 Unlikely”, Nature Climate Change 7: 637-641.
- Chang-Eui Park et al. (2018). “Keeping Global Warming within 1.5ºC Constrains Emergence of Aridification”, Nature Climate Change 8: 70–74.
- Jeremy S. Pal & Elfatih A. B. Eltahir (2016). “Future Temperature in Southwest Asia Projected to Exceed a Threshold for Human Adaptability”, Nature Climate Change 6: 197-200.
- Camilo Mora et al. (2017). “Global Risk of Deadly Heat”, Nature Climate Change 7: 501-506.
- Nick Watts et al. (2017). “The Lancet Countdown on Health and Climate Change: from 25 Years of Inaction to a Global Transformation for Public Health”, The Lancet 391.10120: 581-630. Philip Landrigan et al. (2017). “The Lancet Commission on Pollution and Health”, The Lancet 391.10119: 462-512.
- Wikipedia has a page on the topic, which seems to be kept up to date quite well.
- E. Schuur et al. (2015). “Climate Change and the Permafrost Carbon Feedback”, Nature 520: 171-179.
- Except that it would automatically stop if all carbon would be released, of course. And that is a scenario that we should avoid as it would kill off pretty much everything on the planet.
- There is also a lot of methane stored in the permafrost under the Arctic Ocean and that is also melting. However, most of this methane may be absorbed by the sea. As far as I know, there currently is no evidence that this methane is reaching the atmosphere.
- Caspar Hallman et al. (2017). “More than 75 Percent Decline over 27 years in Total Flying Insect Biomass in Protected Areas”, PLOS One 12.10: e0185809.
- Clionadh Raleigh, Hyun Jin Choi, & Dominic Kniveton (2015). “The Devil is in the Details: An Investigation of the Relationships between Conflict, Food Price and Climate across Africa”, Global Environmental Change 32: 187-199.
- Christian Parenti (2011). Tropic of Chaos: Climate Change and the New Geography of Violence (Nation Books).