MEDEAS: The Next Step after the Paris Climate Agreement

Jordi Solé, coordinator of the MEDEAS project speaks in Brno (Czekia) on Feb 15th, 2017. The European project MEDEAS has the ambitious goal of providing the tools necessary to put into practice the 2015 Paris agreement on climate

Let me start with something to dispel the confusion about what models are for. When you deal with complex, adaptive systems, models are NOT meant to predict the future. As John Gall said in his book on complex systems, "systems always kick back" - to which I may add, "and sometimes they kick back with a vengeance". (another way to express this concept is "forecasting always fails.")

But if dynamic models cannot predict the future, what are they good for? Simple, they are about being prepared for the future. Think of the Paris climate treaty of 2015. It was the result of millions of runs of various climate models, none of which claimed to predict "the" future. But these models are tools to prepare for the future; they tell you what may happen, depending on what you do. They are tools to shape political decisions. Out of all those runs, a goal was extracted, a setpoint, a number: "we don't want temperatures to rise of more than  2 °C and, for that purpose, there is a limit to the amounts of fossil fuels we can burn." It was a political decision that took into account not just what the models say, but what could be concretely achieved in the real world.  No model would give you that number as an output.The Paris agreement was a masterpiece of diplomacy and of communication strategy because it concentrated so much noise into a simple, stark, number: a goal to reach.

And there we stand: with Paris, we set the goal, but how do we get there? This section of policy planning was poor in Paris, where the best that could be done was to line up the INDCs, the intended nationally determined contribution; that is how single countries think they could reduce emissions. That's not planning, it is a first stab at the problem; it shows the good will to do something, but no more. As they stand, the INDCs won't get us far enough.

So, we are again at the task of getting prepared for the future. We know that we need to reduce carbon emissions, but how fast? Besides, it is not just a question of reduction, it is a question of substitution. We need to maintain the essential energy services to the world's population: surely, as a society, we can shed a lot of fat and keep going, but without a minimum of energy input, the system collapses. At the same time, we need to maintain the current input without exceeding the emissions limits. A difficult challenge, although not an impossible one.

Here, we need models, again. No model can tell you exactly how to get there, but models will tell you what is likely to happen given some choices and some decisions. And out of the models, you have to extract a concrete, politically feasible goal: how to invest the remaining resources into attaining the Paris objectives? In other words, what fraction of the world's GDP need to be invested in the transition to a renewable economy?

Giving an answer to this question is the ambitious task of the MEDEAS project which has now reached a full year of work and set up the basis for an extensive modeling effort. MEDEAS takes an approach mainly based on system dynamics, similar to the one of the well-known "The Limits to Growth" approach. It is not the only ongoing project in this area, others projects take different lines of approach. But in al cases the idea is to build up knowledge on what is needed for the transition. Some data are already available that tell us we need a major effort to replace fossil fuels fast enough. The transition that won't come by itself, pushed by purely economic forces. But we need to explore the issue more in depth before these considerations can be turned into a number that can be agreed upon by the interested parties. We need to take into account both what's needed and what is politically feasible. Then, we will have a goal to reach.

If you want to know more about MEDEAS, you can see the MEDEAS website. There is also a MEDAS newsletter, still in a preliminary phase. And, if you would like to be involved, contact me (ugo.bardi(strangething)unifi.it)


Below: an intense discussion held in Brno about the project with the coordinator, Jordi Solé from Barcelona and two Italian researchers from Florence, Sara Falsini and Ilaria Perissi. 

2015: the Year that Changed Everything?

Recent wildfires in California, photo from the Independent

There has been no lack of disasters taking place in 2015. Some can be classified as "natural" others as human caused. In all cases, anyway, they are an indication of the stress felt by the ecosystem and by the economic system at the same time. We are, finally, reaching our limits as we knew we had to, from the time when we were warned, in 1972, by the study titled "The Limits to Growth."

But not everything was bad in 2015 and, in this post for the end of the year, let's concentrate on the good things that happened. If we do that, we see that 2015 has been a very special year. Not that any of the big problems we face has been solved; but there is something new going on; something unexpected, but that may give a boost to a new direction that the world may take; a direction that may lead us to a better world. We may be learning something, after all.

So, let me list some of the good things that happened in 2015

- The Papal Encyclical on climate, the "Laudato si'". This has really been something big. For one thing, it was clear from the way it affected the debate. Mostly, climate scientists, and scientists in general, are no-nonsense people, often atheists or agnostics, rarely churchgoers. So, the arrival of the Pope in the debate took them by surprise: "The Pope? What? Does he agree with us? Really? He said that God orders to us to safeguard the creation..... Eh....?" You can't imagine how happy these solemn scientists were; like children receiving a Christmas gift in August! But the main effect of the Pope's encyclical has been on the anti-science camp. They were, clearly, in difficulty. As a reaction, they could have demonized the Pope, saying that he is a communist, or he is possessed by the devil, or something like that. Some weirdos have done exactly that but, by far and large, the mainstream anti-science camp has decided that their best (and probably the only) strategy was to keep a low profile and hope that the "Laudato si'" would be ignored and then forgotten. It wasn't and it won't. The effect of the encyclical has been large on the public's understanding of climate change. It is an effect that's continuing and that can only increase in the future.

- The COP21 climate conference in Paris. I know that many people say that not enough has been obtained, which is true. But it is also true that the conference has been a success mainly in showing the marginality of the anti-science camp. They had spent so much money trying to demonize science and scientists, trying to ridicule climate science, spreading various conspiracy legends and then, what? They found that the delegations of 190 countries in Paris declared that climate change is real, it is human made, and something must be made to stop it. Now, think about that: if you were in their shoes, how would you feel? That's the main reason why the Paris conference was a remarkable success. It was just a first step, of course, but you can't go anywhere without a first step!

- The new perception of the need of clean energy. This year has seen a true explosion in the endorsements of renewable energy. A set of technologies that once were seen as just toys for Green Nerds, now are increasingly seen not just part of the solution of the problem of climate change, but THE solution. Among those who came out strongly in favor of renewable energy in 2015, I can cite Arnold Schwarzenegger, Michael Klare, Naomi Oreskes, Bill Gates, and, yes, the Pope himself! True, not everyone has understood exactly the terms of the problem. Some, like Bill Gates, still think that renewables need to be substantially improved before being deployed, without realizing how pressing is the need of the renewable transition. Others have understood that energy is the problem, but they picked up the wrong solution: nuclear energy - as James Hansen and others did. Within some limits, it is an understandable mistake on the part of people who are not energy experts, but, at least, they understood the need of producing energy. This is the real change in perception: we are moving from a perception that sees emission reductions as the priority to a perception that sees clean energy production as the priority. If we can manage to produce clean renewable energy at a cost lower than fossil energy, then we'll move to renewables without the need of laws, treaties, and special taxes (and we can do that, already!)

- The collapse of the oil markets. At first sight, low oil prices would seem to be exactly the opposite of what we need to fight climate change. But that's not the case: think that we have been telling people that we need to "leave oil in the ground" without much success, so far. But now low prices are doing the job for us by making extraction unprofitable! The low oil prices of 2015 show the impossibility for the market to keep producing from expensive (and dirty) sources such as shale oil. As a consequence, the shale oil industry giving out its death rattle and we are facing the start of the terminal decline of the world's oil production. That will carry with it the decline of all fossil fuel production. The importance of this event can hardly be underestimated. It means that the decline in emissions is likely to be much more rapid than anything that was even vaguely imagined at the COP21 in Paris and that the scenarios contemplated in the INDCs (Intended Nationally Determined Contributions) will soon be as obsolete as flying cars and nuclear water boilers. The emission decline could even take the shape of a "Seneca Collapse" that might stop the growth of greenhouse gas concentrations short of the dreaded climate "tipping point". That would surely be a good thing but, of course, a Seneca collapse of the world's energy production would be a major disaster in itself; possibly able to destroy the world's economic system. But there is a middle way: the Seneca effect could help us manage to sharply curtail fossil fuels use, but not so much that we would be left without the resources needed to build a new energy system based on renewables. It is difficult, but not impossible, as shown by quantitative calculations.

Of course, things might go wrong in other ways. For instance, a major war could push up the need of fuels and cause the oil industry to restart extracting resources that a market economy cannot extract. It is possible, indeed, that the current drive for war is the result of exactly this kind of considerations. Nevertheless, war is not unavoidable and, if we manage to avoid it, then 2015 may be remembered as the year when everything changed. A year of hope!

The COP21 in Paris: it was a victory

After a series of defeats suffered at the hands of the Swedes, the Russian Czar Peter the Great is reported to have said that, "Eventually, they'll teach us how to beat them". Then, in 1709, at Poltava, the Russian army decisively defeated the Swedes. Victory often comes from persistence and if we keep fighting for the earth's climate, eventually we'll win (Image by Mikhail Lomonosov,1762-1764 )

Before the COP21 meeting, I expected that the agreement that was to be signed would be something like the one that was actually signed. And I saw myself taking a position similar to the one taken by James Hansen and others: I thought I would have joined those who are now screaming "hoax!"

But no; after some thinking over the matter, I had a minor enlightenment. The Paris agreement is a victory. Maybe not a great victory, because from a technical viewpoint it is certainly insufficient. But, in communication terms, there is no doubt that it is a victory.

Put yourself in the shoes of those who have been pouring millions of dollars into "perception management" on climate (that is, good old "disinformation"). They might have thought that, after the Climategate story, after the demonization of Michael Mann, of Al Gore, of Phil Jones, and of many others; after that all the Republican candidates were convinced to refuse to admit that climate change is human caused, after the Trumpcane, and more things, then, the idea of human-caused climate change would be erased from the collective consciousness and its proponents reduced to the same level of prestige that Saddam Hussein enjoyed in the West when he was president of Iraq.

And yet, climate science is not dead and the concern about climate is alive and well in the world. The COP21 in Paris has shown that. So, the Paris conference is a victory because it showed the resilience of the climate movement. We have been attacked, ridiculed, demonized, harassed, insulted, dismissed, threatened, punished, and more. But we are still here. And we are growing. We are also getting smarter. We haven't won, yet, but we are learning how to win.

So, "they" must be thinking: what was all that money good for? Don't you think they are now thinking about whether putting some more money into a losing battle is a good idea? They may even be scared: it is shown by the reactions to the news of the agreement. Sometimes nasty, sometimes silly, sometimes rabid; always in a defensive mood. Look at this report, where the secretary general of Eurocoal has declared that the coal industry “will be hated and vilified, in the same way that slave traders were once hated and vilified" If this is not panic, what is?

This story reminds me of something that Peter the Great said after he was defeated, one more time, by the Swedes, "eventually, they'll teach us how to beat them". Then, there came the Russian victory at Poltava and the Swedes never were again a threat for Russia. In war, just as in most things in life, persistence is the essential quality. If we keep fighting, we'll win the climate battle.

Five scenarios for the post-COP21 of Paris

Scenarios are not predictions, just ways of describing possible futures; useful in order to be prepared for unexpected events. The only rule in scenario building is that the assumptions should not be too improbable; such as involving time machines. And, yet, it seems that in some cases involving climate projections, time machines are a built-in assumption. 

The COP21 conference in Paris has brought again climate to the attention of the public and, from now on, there starts the real challenge: what can we really expect for the future of the earth's climate? As always, predictions are difficult, especially when there are many variables involved. Nevertheless, climate change is the result of physical factors that we can understand and we know that the build-up of greenhouse gases in the atmosphere - if it continues - is going to lead us to a very unpleasant future.

If we look at the long-term future, the whole question rotates on whether we manage to stay below an increase in temperature that is believed to be "safe" (it might be 2 degrees C, but we don't know for sure), or we pass the limit and we find ourselves above the "climate tipping point" after which the system starts moving by itself toward more and more warming with all the associated disasters.

So, I thought I might engage in a little exercise of qualitative "scenario building" with a special focus on climate. Here are some scenarios; listed in no particular order. Some you could see as horrible, some as unlikely, others as overoptimistic. But they are just that: scenarios. The COP21 was a step in the right direction. Avoiding the worst outcomes will not be easy, but it is up to us.


1. Business as usual. In this scenario, things remain mostly as they are today; just gradually worsening. There are no major wars, no abrupt economic collapses, no sudden climate disasters. But temperatures keep increasing while the world's economic system is battered by one crisis after the other. So, the economy gradually loses the resources necessary to keep alive the structures that study and understand global problems: universities and research centers. As a consequence, global problems slip away from the collective consciousness. People get killed by heat waves, starved by droughts, and swept away by monster hurricanes, and still no one is able to connect all that to climate change, while the burning of fossil fuels, although reduced because of depletion, continues. In the long run, that would lead to the end of civilization by a whisper, rather than by a bang.

2. The climate panic.  This is the symmetric and opposite scenario to the above. As the climate crisis gets worse, we may arrive at a "perception tipping point;" maybe generated by some spectacular event (e.g. a monster ice calving from Antarctica or Greenland) or, simply, by the accumulation of evidence. A wave of climate panic would lead to a scramble to "do something" and things might worsen rather than improve if some extreme forms of geoengineering were attempted. However, it might also lead to positive results. For instance, a push for reforestation and for renewable energy would effectively mitigate climate change. It is not obvious that our civilization needs a burst of panic to be saved, but that might give us an extra chance.

3. The Seneca collapse. Before being hit by some climate disaster, the world's economy could experience a "Seneca collapse" as the result of resource depletion.  such a situation, people would have no time to worry about anything but their immediate survival and that would lead to climate change being completely forgotten. On the other hand, the economic collapse would cause a reduction in emissions probably well beyond even the wildest dreams of environmentalists and might be sufficient to avoid to go above the "climate tipping point". Then, of course, such a collapse would be a disaster in all other terms; causing the probable disintegration of the whole world's economy. Nevertheless, it might still give us a "window of opportunity" to restart from scratch with a new renewable energy infrastructure and then rebuild a new and better society.

4. The warring states. The present situation has been likened to the beginning of the first world war and there are serious risks that the ongoing conflicts will escalate into a major worldwide confrontation. In such case, all the worries about climate change would be immediately forgotten. A major war would likely boost the efforts to extract as much fossil fuels as possible, including, probably, the oil shales that pure market forces seem to be unable to extract (it may be that the current drive for war arises in part from this kind of considerations). That would lead to emissions spiking up, at least for the duration of the war. On the other hand, it is likely that any major war would rapidly peter out because of the lack of energy and resources to carry it on. So, the carbon spike won't last long. Still, it could do a lot of damage, making things even more difficult.

5. The nuclear holocaust. A variant of the war scenario, it assumes that one or more contenders would decide to play the nuclear card. That could take the shape of tactical or strategic nuclear bombing or also that of attacking the adversary's nuclear plants utilizing conventional weapons. In all cases, we would see a rapid drop of the carbon emissions as large industrialized areas would be destroyed or just rendered uninhabitable. A massive nuclear exchange would also generate so much dust in the upper atmosphere that the result could be described as a "nuclear winter" causing an extreme cooling that might do even more damage than warming. However, that would do nothing to change the long-run effect of the greenhouse gases already emitted in the atmosphere. The dust would eventually settle down and the warming restart with a vengeance.

6. Depopulation. Most current projections assume that the human population will keep smoothly increasing throughout the 21st century, plateauing at around 9-10 billion individuals, or perhaps more than that. However, the historical record shows that human populations rarely follow this kind of trajectory, more often tending to collapse after having peaked. A good case in point is that of Ireland, between 1845 and 1850, when population crashed to about half of the size it had at the peak. The world's population might collapse in the same way as the result of wars, epidemics, pollution, of someone playing games with biological weapons and it might not be impossible to lose several billion people in a few decades, or even faster. The result would be a strong reduction of the greenhouse gas emissions, albeit obtained at a price that nobody would want to pay. However, people would continue burning fossil fuels and the cumulative amount of the greenhouse gases in the atmosphere would continue increasing. So, it is not obvious that even this extreme scenario could lead to avoiding the climate tipping point.

7. The renewable revolution. Renewable energy is the wild card of the situation. It is already efficient enough that it can outcompete fossil fuels and it could grow fast enough to replace them before it is too late. Assume that people understand both the advantages of renewable energy and the desperate need we have to stop burning fossil fuels, then we could arrive at a "bottom-up" revolution in which we don't need government-enforced emission trading or a carbon tax. A situation in which even climate science deniers wouldn't be so silly to pay more for dirty fossil energy when they can have cheaper and clean energy. In the end, the battle for climate would be won when a consortium of renewable companies buys Exxon and closes it down. Problem solved and it is the beginning of a new era.


We could combine some of these scenarios together, or think of different ones. The only rule is that they shouldn't be too improbable. For instance, we shouldn't include scenarios dealing with an alien invasion of the planet or with the COP97 being held in Siorapaluk, in Northern Greenland, in 2074 finally arriving at a binding treaty on the phasing out of fossil fuels. Apart from this, the future always surprises us. Just don't forget that the future cannot be predicted, but that you can be prepared for it.

How to build a safe plane according to the COP21 in Paris

In the 1950s, a series of crashes affected the "Comet,"  a plane that was supposed to be a major innovation in aviation. The main reasons of the disasters can be attributed to the general atmosphere of technological optimism that pervaded the 1950s and that led engineers to overestimate their capabilities. The Comet was a hard lesson to learn, but it was learned. Today, the industry is extremely conservative and modern planes are way safer than they used to be.

Several years of work with materials for turbine engines have taught me  how careful is the aerospace industry about the safety of their products. Of course, nobody wants to think about planes crashing, not even aerospace engineers, but they must. There is no such thing as an "alarmist" in the aerospace industry. So, the industry is extremely conservative and careful; nothing goes inside a plane unless it has passed rigorous tests and having been conclusively demonstrated to be safe and conforming to the specifics. That is what makes planes one of the safest existing transportation systems.  

Now, imagine now to handle the management of the earth's climate to aerospace engineers. They would quickly understand that the earth's ecosystem can crash; meaning that it can warm up out of control as the result of the build-up of greenhouse gases in the atmosphere. And that can kill almost everything on the planet: it has happened in the past and there is no reason to believe it is impossible now. That would be the equivalent of a major plane crash; as they say in the industry a "hull loss." So, if the planet were a plane, it would have to be immediately grounded. Safety dictates that we should stop burning fossil fuels from now.

Unfortunately, it seems that the rules that hold for the aerospace industry are not valid when it is question of managing the earth's atmosphere. Let's suppose that a plane were to be built by the methods used in Paris.

How to build a safe plane according to the methods used in the COP21 in Paris.

1. A large group of politicians and bureaucrats convenes in a city in order to decide the specifics of the plane. Aerospace engineers provide advice, but they are not the ones responsible for the decisions made.

2. Those engineers who worry that the plane could crash are branded as "alarmists" and removed from the design process. Politicians not attending the conference declare that it is impossible that any plane can ever crash and that all the worries about planes crashing are only the result of aerospace engineers lobbying for fat research grants. 

3. The specifics of the plane, speed, range, size, etc, are decided by a debate among politicians, while grassroots activists march in the streets asking for better planes.

4. No one designs the plane, Contractors provide their own specifics for each subsystem (wings, engine, control system,etc) in total autonomy. Nobody can say whether these subsystems will work together and whether the result will be a plane that can fly.

5. The management of the conference has no power to modify the proposals of the contractors, nor to make sure that the specifics that have been listed will actually be met once the subsystems are delivered for assemblage. 

6. The conference is concluded with the politicians declaring that the plane will fly.  

7. The first test flight will be performed with the plane fully loaded with passengers.

h/t Richard Heinberg

Climate negotiations ? What climate negotiations? The Italian press ignores COP21

Can you spot the box about the climate negotiation in Paris in the site of the Italian newspaper "Quotidiano.Net"? It takes a certain effort, but it is right there, the third in the right column, just below the news about soccer and just above the news about a pornstar.

In the image on the right, you can have a better idea of the prominence given by QN to the Paris conference (look at the text circled in red). And QN, a major coalition of newspapers in Italy, is not alone in ignoring the COP21. Here are the results of a brief survey that I made on the web pages of the major Italian dailies today.

La Repubblica. "repubblica.it" (the main "progressive," so to say, newspaper in Italy). The climate negotiations are the n. 7 in the list of the news. The first is terrorism, then there is the Pope, the need of economic growth, something about AIDS, scandals in Rome, etc.

La Stampa. "lastampa.it"  Mainstream "moderate" newspaper: the climate negotiations are n. 12.

Il Corriere. "ilcorriere.it". Moderate newspaper. One brief paragraph mentions Hollande's declarations on terrorism and climate. It is n. 3 in the list.

Il Giornale "Ilgiornale.it" - (extreme right): no mention of the climate negotiations

Libero. "Liberoquotidiano.it" (extreme xenophobic right) - no mention of the climate negotiations.


In terms of communication success, this is not an auspicious start for the climate negotiations. Better said, it is a complete flop, at least in Italy.

Climate: walking along a mountain path with our eyes closed, hoping that the cliff is still far away....

The danger of climate change continues to be widely misunderstood and ignored.

The COP21 of Paris is starting and trying to gain a slot in the mediaspace. But, at best, it will be a short flare of attention; soon fading in the general indifference. Climate change, it seems, is seen as something remote; its importance dwarfed by more immediate threats; from terrorism to financial concerns. And governments seem to suffer from a split personality disease; with politicians flocking to Paris to declare the absolute need of saving the planet for the future generations and then going back home and declare the absolute need of restarting growth.

But the climate threat is not for the future generations. It is something that's going on now, that has been going on for a century, and that keeps going, taking us along a dangerous path that ends somewhere, probably with a steep cliff.

Here is a summary of the situation as it is today. It doesn't attempt to be exhaustive, but it tries to catch the main points of what's going on.


1. Temperatures. Climate change is not just about rising temperatures, but that's probably its most direct and visible manifestation. The earth as been getting warmer and warmer during the past century or so and, today, the so-called "pause" is over, if it ever existed. 2015 is on track to be the hottest year ever recorded, with good chances that 2016 will be even hotter. We are very close to, or we have passed,  1°C of average surface temperature increase in comparison to pre-industrial times. The effects of this warming are multiple: droughts, heat waves, glacier melting, sea level rise, and more. And the more the earth warms up, the more these effects are important.

2. Greenhouse gases.  Carbon dioxide and methane are the main greenhouse gases generated as the result of human activities. Their buildup in the atmosphere continues. About CO2, 2015 was probably the last year in history when humans could breathe an air containing less than 400 ppm of it; from now on, concentrations will be higher. We don't know what effect these concentrations will have on people, but we know that humans had never experienced an atmosphere with more than 300 ppm of CO2 during the more than a hundred thousand years of their existence as a species. We also know that the human cognitive process is already measurably impaired at concentrations under 1000 ppm. Regarding methane, concentrations are also rising after a period of stasis that had lasted until 2006. There exists the worrisome possibility that increasing temperatures will generate a "tipping point" in which the release of methane trapped in the high latitude permafrost would become an independent and out of control source of greenhouse gas. So far, there is no evidence that this is happening, but there are worrisome reports of bursts of methane released from craters in Siberia.

3. Ice melting and sea levels. The melting of the icecaps and glaciers continues unabated. The risk of some major instabilities exists, for instance in Antarctica; even though no spectacular events have occurred, so far. Some studies seem to indicate that Antarctica has been gaining some ice up to 2008 owing to increased snowfall but, even if that turns out to be true, the overall melting trend is evident. The melting of continental glaciers is destabilizing the mountains, causing extensive landslides. The freshwater flow into the oceans is one of the main factors causing a rise in sea levels. At present, we stand at a level some 20 cm higher than when the measurements started, in late 19th century. So far, no coastal city or inhabited island has gone underwater permanently, but if the rising trend continues this is going to become a gigantic problem.

4. Weather and climate related disasters. The changing weather patterns are one of the factors that have generated a rapid increase in natural disasters during the 20th century. The number of disasters appears to have peaked around 2004-2006, even though the damage done keeps increasing in monetary terms. The change in weather patterns is causing considerable damage to agriculture, affected by droughts (as it is happening in the US)  and by unstable rainfall patterns. So far, food production has not been heavily impacted, at least on the average and the production of cereals remains stable, or even increasing. However, poor countries are especially at risk since farmers do not have the financial resources needed to adapt. Fishery production is in decline almost everywhere, mostly because of overfishing, but also as a result of oceanic warming.

5. Other effects. All the above are effects that can be classed under the "climate change" label, in turn an effect of the warming caused by greenhouse forcing. However, the ongoing changes in the ecosystem are much more complex and extensive. For instance, oceanic acidification is taking place as an effect of dissolved CO2 to a level of some 0.1 pH units and that may already have negative effects on corals. We would need to consider eutrophication, soil erosion, heavy metal dispersal, land coverage by permanent structures, multiple extinctions, deforestation, and much more.


Even though short, this list shows how gigantic and mostly irreversible changes are taking place. The earth changing, it is being transformed into a different planet, an environment that our ancestors never experienced, but that we cannot avoid facing. In this situation, a certain degree of adaptation is certainly possible for humans. Air conditioning can help against heat waves, agriculture can adapt to droughts by irrigation or by switching to different varieties of plants, engineering works can help against flooding, and fires can be suppressed by various methods. But there are limits to adaptation and the problems tend to come not gradually, but all of a sudden. For instance, when New York suffered a disastrous flood, in 2012, the sea level rise was certainly a factor that worsened the problem.

In many cases, we are seeing a situation in which major climate-related emergencies could occur at any moment. There are various possibilities; such as a new heat waves comparable, or worse, than the one in 2003 that claimed some 70,000 victims in Europe. We may see the collapse of major chunks of ice from Antarctica or from Greenland, that would lead to a disastrous sea level rise. Or changes in the weather patterns badly affecting agriculture and hence food production. Or something else; in any case, as the greenhouse forcing continues to increase, these possibilities become more and more likely.

Capping all this, there is the ominous possibility of the "climate tipping point", the fact that after reaching a certain degree of warming, the whole ecosystem will start releasing methane stored in the permafrost, pushing itself to a new temperature state. This new state could be so hot to make most of the planet uninhabitable for human beings. Obviously, there is no way to adapt to such an event.

Against all this, the efforts of the conference of Paris appear unlikely to have a large effect, to say the least. The conference is not supposed to reach any binding agreement and there is little chance that it will arrive to an agreement sufficiently strong to ensure that temperatures will remain within the "2 C" warming limits, even assuming that such a level could be considered "safe."

Yet, it would not be impossible to stabilize climate by switching to an economy fully powered by renewable energy before it will be too late. But that requires sacrifices that, at present, nobody is willing to make. So, we keep walking along a mountain path with our eyes closed, just hoping that the cliff is still far away.....