GW = AGW = CAGW?

As a non-native English speaker, I often encounter new words. One such word is “equivocation” (using the same word for different things or the use of such word in multiple senses throughout an argument, leading to a false conclusion). The first time I heard about it, I recognized it as something that is frequently used in global warming/climate change communication.

At the end of last week, when searching for something related to the consensus, I landed at the Skeptical Science page titled The 97% consensus on global warming (intermediate version). I am pretty sure that I must have read this before, but having “equivocation” at the back of my mind, gave it a new dimension.

As the title suggests, its subject is the 97% consensus. It starts from the statement of the Petition Project that “there is no convincing scientific evidence that human release of carbon dioxide will, in the foreseeable future, cause catastrophic heating of the Earth’s atmosphere”.

The Skeptical Science author calls this a myth and tackles it by explaining that a consensus of around 95% is found in papers like Cook et al 2013 & 2016, Oreskes 2004, Doran 2009 and Anderegg 2010. Also mentioned are the Vision Prize poll that basically found something similar and a list of scientific organizations that endorse the consensus.

I don’t know much about the Petition Project, but from the excerpt given in the Skeptical Science article, it is clear that the Petition Project statement is very specific. They claim that there is no consensus specifically on the catastrophic nature of global warming caused by human emissions.

Advertisement

Define “AGW”

Spread over the Cook et al 2018 paper are the terms “anthropogenic climate change” and “anthropogenic global warming”. It is also mentioned a in table S2 of the supplementary material. I assume that “anthropogenic global warming” means that global temperatures are rising and humans have an impact. This seems to be supported by the consensus claim from the paper (my emphasis):

There is an overwhelming scientific consensus that humans are causing global warming (Cook et al 2016), with a number of studies converging on 97% agreement among publishing climate scientists or relevant climate papers (Doran and Zimmerman 2009, Anderegg et al 2010, Cook et al 2013, Carlton et al 2015).

That is a far cry from the previous statement in the Alice in Wonderland paper. In that paper, the claim was made that there is a consensus that global warming “presents a global problem”. A claim that obviously was unsupported by the papers that were referenced.

At least he skipped the “dangerous” part of the claim. It is now in line with what the referenced papers researched. As explained in the link above, the referenced papers investigated the claim that global temperatures are rising and that humans have an influence in this. Not whether it is dangerous. Not whether something should be done about it.

However, I don’t think that the term “AGW” is used in this way in the paper. This sentence in the abstract makes me think that he means something different (my emphasis):

Global Warming: the definition that fits everything

After the early winter with heavy snow in the North-East of the US, the debate again raises whether this is a result of global warming. On the one side there is the belief that this early winter weather in the North-East of the US is linked to global warming and on the other side there is the remark that one can not have it both. And every position in between.

“But”, would you say, “Couldn’t it be perfectly possible that global warming causes warming as well as snow?”. In a way, that is entirely possible. Sure, if global warming is real this could mean local temperatures go up, maybe even also droughts. Not hard to understand. When because of a polar vortex, cold air blows across a warmer water surface this will produce snow, maybe even lots of it. That is a known phenomenon.

It is of course a bit more complicated than that. The big question is: what is our definition of “global warming”? And do we all use the same definition?

Surprise, surprise, we don’t.

Hooray, government policies may have slowed down global warming!

After a week in the South of France I am back at home and it is time to catch up on the news. One of the news stories that drew my attention was the UK Energy Minister, Baroness Sandip Verma, claiming that policies might play a role in curbing rising temperatures. See also the transcript of the debates in the House of Lords of October 27, 2014. The answer came after Viscount Ridley questioned when warming would start again:

My Lords, does my noble friend the Minister agree that the fifth assessment report of the Intergovernmental Panel on Climate Change has confirmed, in the same words, that there has been a “hiatus” in global warming for at least the past 15 years? Will she give us the opinion of her scientific advisers as to when that hiatus is likely to end?

In fact not a bad question, we hear all the time that the science behind global warming is clear. Wouldn’t that be a nice test to see how clear it really is?

But the answer was not exactly what I was expecting:

My Lords, my noble friend raises a couple of issues that we would dispute in a longer debate. What we do recognise is that a change in weather patterns is happening across the globe and that climate change is occurring; it may have slowed down but that is a good thing, and it could well be that some of the measures we are taking today have helped that to occur. If we are to respond seriously to climate change and changing weather patterns, we need to be able to put in place things that mitigate and adapt to those different patterns.

It reminded me about myself some 6 years ago. My switch from believer towards skeptic started with the question whether climate policies made a change in the form of a colder autumn. I know, I know, I was very naive at that time. But it was the beginning of a search that cumulated in this blog. The question made me think and in the end reconsider what I thought was obvious.

It clearly didn’t have the same effect on the Minister. The statement that the global warming hiatus might be related to some of the decarbonization measures is of course utter nonsense. There is one tiny little problem with his statement: until now CO₂ was claimed to be CAUSING global warming and despite all the measures that have been taken, global emissions are still INCREASING.

Going to Bordeaux just by staying at home

In today’s newspaper (Het Nieuwsblad) I found a small article on the last page about extreme weather and global warming. At first it made me roll my eyes…yet another climate report…sigh. But when reading the article I was very surprised it even reported on possible advantages of global warming (assuming those predicted changes are actually true of course).

The origin seemed to be the The KNMI’14-climate scenarios and Climate Scenarios, four scenarios based on recent results of climate research and the newest report of the IPCC.

I found other newspapers that reported on it, for example More extreme weather: winter in the Netherlands will be like winter in Bordeaux (in Dutch). That title caught my attention, it let me think about a post I wrote a month ago after a week in the South of France: How could the French ever survive in the South of France?. In which I explained that I wasn’t really impressed by the “worrying” thought of us, Belgians, having the climate of the South of France.

The same weather as in Bordeaux, that is something that wouldn’t impress much people in this region. If I compare this with the global warming reporting until now, this is rather soft. Am I getting weak or is something changing in global-warming reporting?

Global Warming as distracter

A week ago I heard the news that the Kiribati man who was seeking asylum in New Zealand because “rising seas and environmental risks caused by global warming” had lost his appeal. To recall: he came to New Zealand in 2007 and was ordered to leave the country. He then claimed he couldn’t safely return to his country because of global warming and the sea level rise. Asylum was refused on the grounds his claim fell short of the legal criteria, such as fear of persecution or threats to his life. He then appealed the decision. Now he fears deportation because he lost the appeal.

The verdict was of course not based on science or facts, but on juridical analysis. Juridically he didn’t fulfill the current definition of a refugee although his lawyer took great effort in trying to change the definition of “persecution”. They now consider taking the case to the United Nations Human Rights Committee.

One question kept buggering me: how could such a case ever been started? If we look at the sea level rise in the Kiribati area, it is remarkably stable. A study found that some islands there even increased in size. Yet, now someone is pleading that his country is not able to care for its inhabitants anymore and will be engulfed by an assumed rise somewhere in the future. Without seeing an actual rise. Looking at the data and considering that these are not islands but atolls, should at least put some question marks with these claims.

It made me think about another situation. Last year at the Warsaw summit, the developing countries walked away from the negotiations because their expectations of being compensated for the historic emissions of the developed world were not fulfilled. Scientists, politicians and the media told for many decades that CO₂ is the culprit of extreme weather and therefor there is a need to limit its emissions. The developing countries took that for granted and claimed compensation because of this wrongdoing of the developed countries.

None of these are based on an actual threat, but on assumptions, on mathematical models, but also on politics. The overstatements have their origin in keeping fear alive. The fear that many bad things could happen, so to influence other people/politicians in supporting their solution. Fear is of course a powerful political instrument, but playing with fear can have unintentional consequences.

After stating CO₂ responsible for all things bad and even boldly stating that our past emissions amplifying and/or even causing storms such as Haiyan, it would come as no surprise that developing countries make an emotional appeal for compensation of this injustice. Even if there is no link found between our emissions and storms. Yet politicians keep on feeding this idea in an desperate move to influence decision making. What would happen in the next summit in Paris 2015 is rather predictable.

After stating CO₂ responsible for (global) sea level rise, it would come as no big surprise that inhabitants of atolls declare there is no future for them and they need the money or a residence in the developed world. Even if sea level is stable in their area. It has nothing to do with the science or the facts. We made it very easy for them for them to come to such a conclusion.

Don’t take me wrong. Cebu and Kiribati have real issues that have to be met. Haiyan struck poor people that were not prepared. Helping them is a no brainer. Kiribati has an issue with overpopulation and more impact on the environmental than it can handle. But connecting them with global warming is distracting from the real issues and therefor is not going to help to solve them.

Is Anthropogenic Global Warming by definition Catastrophic?

It have been said many, many times before. There supposedly is a scientific consensus that increasing anthropogenic CO₂ concentrations in the atmosphere are responsible for most of the warming we experienced. It has been said in many variants and is said to justify (immediate) action on climate change.

In the two last posts I wondered what exactly there is a consensus about? My take is that it might be something different than what is communicated.

A couple weeks ago I looked at the Crossing the 2014 Climate Divide: Scientists, Skeptics & the Media video. The first three posts of March were about the first part starring Suzanne Goldenberg (The Guardian). In it also Naomi Oreskes was present. She talked about her experiences with the skeptics and how she entered the climate debate. It was mostly about the extremists, you have them on both sides, not really interesting for me. But it was also about how she came to believe and documented the “consensus”. That was more interesting. Her work is widely cited by many alarmists as a confirmation of the existence of the scientific consensus on global warming.

This is how it was presented: BEYOND THE IVORY TOWER – The Scientific Consensus on Climate Change. What she did was downloading the abstracts of 928 peer reviewed articles which she found when entering the key words “global climate change” for the period of 1993 until 2003 in the ISI database (Institute for Scientific Information).

The question she had was how many papers disagreed with the position of the US National Academy of Science and the IPCC:

Human activities … are modifying the concentration of atmospheric constituents … that absorb or scatter radiant energy. … [M]ost of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations

The conclusion was none: 75% of the articles accepted the “consensus” and 25% were taking no position. This is a subjective thing. Some others have tried this and came to other conclusions. But I have no access to the ISI database, so I will not go there. I will try to look at the method and the definition to see how far I get.

The first statement is something everybody can agree with, at least I have not seen someone disagreeing with that. The Keeling curve learns that the CO₂ concentration is rising, at least since 1958 when measurements began. Nothing controversial here. But at such it doesn’t proves much.

Greenhouse gases absorb or scatter radiant energy. Also nothing controversial here.

The last statement seems detailed at first glance, but is a bit more ambiguous:

• Most of the warming: most is rather ambiguous. It is at least from somewhat above 50% until a bit less than 100%. Let alone how to quantify “most” in an abstract. Okay, let’s assume that this is possible and it is reliable enough to measure the abstracts.
• Likely: according to the IPCC this means larger than 66%. Okay, there is at least 66% chance that “most” of the observed warming over the last 50 years is due to increase of greenhouse gas concentrations. That means there is 34% or less chance that “most” of the observed warming over the last 50 years is NOT due to the increase of greenhouse gas concentrations.

However, the obvious missing part is the fact that nowhere is stated that this increase is dangerous or leads to catastrophic changes in our climate, therefor needing immediate action. The only thing this statements tell us is that scientists are certain that there is an increased concentration of CO₂ in the atmosphere (which is true), that this absorbs or scatters radiant energy (which is also true) and this could mean that part of this increase is caused by our emissions.

That is really uncontroversial. All the skeptics that I know of agree with that. They acknowledge that there is more CO₂ in the atmosphere because of our emissions, that it is a greenhouse gas and it will give more warming, everything else being equal. There are some differences though. Like how sure are we about the warming considering the scarce climate data we accumulated from the past? How sure are we about the projections of the temperatures into the future? How sure are we about a warmer world worse than a cooler world? Etcetera. Nothing in this position point out that this warming is bad, but that is how it is marketed.

The measured consensus is about something uncontroversial and has absolutely nothing to do with the extent of the assumed danger associated with this warming, nor with the necessity of action to prevent this increase in warming.

The debate is over and all that

Since some years I have grown a thicker skin when it comes to reading climate communications. That is certainly needed at this side of the debate. I thought I had seen it all. That was until I saw this video: Crossing the 2014 Climate Divide: Scientists, Skeptics & the Media, starring Suzanne Goldenberg (U.S. Environment Correspondent, The Guardian) and Dr. Naomi Oreskes, (Professor of History of Science, Harvard University). One mispresentations after the other and I only just listened to the first part were Goldenberg explains about her stance on skeptics.

Basically it went like this: the debate is over, science is settled. Now we have to go on and work out solutions in stead of devoting time to the skeptics that are already far behind the issue.

How on earth does she know all those things for sure? I have read some articles she wrote and, beside some quotes of experts, they didn’t really deal with the science. Yet she shows no shred of doubt when saying that the science is settled and action is needed. It looks like an unconditional trust in (climate) science, at least in the alarmist part of it. The interesting part of it is that her trust in the debate being settled is rooted into something else than science.

But we have been there many times before. It shows my age, but I lived in a time where stomach ulcers were still caused by stress, population on earth was too large already and we would have problem feeding ourselves before the end of the 20th century, in our generation we would freeze to death by an imminent ice age, we would develop skin cancers because of exposure by UV rays coming through the ozone hole, in Northern Europe there wouldn’t be much forests left at the end of the 1990s and Finnish lakes would be without fish, and so on and so on. Although in retrospect they were wrong, sometimes spectacularly wrong, yet science was considered trustworthy also back then. We seemed to have learned nothing from our history.

Don’t get me wrong. I don’t want to say that science is useless of invalid. Knowledge is an continuous process, we learn more about earth, nature, ourself when we go along. But it is a bit ridiculous to declare absolute knowledge about complex research areas like the climate when we have only limited data.

Is that unconditional trust in the media warranted? Maybe, maybe not. From my personal experience I really doubt it. Just a few non-scientific things that show me it is probably not:

• When looking at what gets into the mainstream media, it is sometimes much different than what the scientific paper says. Sometimes even the contrary!
• Scientists in the media seem to talk more like politicians. Other motives than science could be involved here.
• The climategate emails learned that high profile climate scientists expressed their doubts towards each other, but to the press they said they were absolutely sure about the science.
• The unequivocal proof that Global Warming is caused by our CO₂ emissions is not showed yet. And, given the complexity of the research area, that proof will not easy to give.
• That elusive 95% certainty that is repeated often, is only the opinion of a subset of the climate scientists, it is not a calculated value.
• Predictions of how global warming is affecting our lives is ever changing and the theory has to be adjusted every time something unexpected happens. This shows me that there are still large gaps in the science.
• Reliable data of for example global temperature, ice area,… is only being gathered since a couple decades ago (sometimes even a decade ago like ocean temperature). That is just a tiny blip on climate scale. The data gathered before that time is sparse and is “convenience sampling” data. Not much trust can be given to results coming out of that.
• The alarm isn’t caused by the empirical data, but by the climate models that suggest doom and gloom in the far future.
• It is not surprising that scientists thought we might be responsible for the warming of the 1980s-1990s. If CO₂, being a greenhouse gas, causes warming, more of it should surely cause more warming. But it is surprising to hear scientists say in the media that they are sure that additional anthropogenic CO₂ will cause disasters, even though there is little empirical data that supports this.
• …

None of this prove that the absolute truths of the climate scientists in the media are not trustworthy, but it shows me that other motives than scientific could be at stake here.

When hearing Goldenberg talk about the divide it is clear the “settled science” and “the consensus” is really important. Not for the science, it doesn’t advance via consensus. But for the public it is: that settled science makes it easier for those who want to silence their opponents and facilitate climate policies.

Whack-a-larmism

It takes me by surprise every time I hear about “climate scientists are in the disadvantage compared to the skeptics”. It seems so out of touch with reality in which alarmists have almost a free podium in the mainstream media and employ tactics that wouldn’t be out of place in politics. With the same surprise I read the opinion piece of Simon Donner in the Vancouver Sun titled Scientists certain human activity causes climate change with the subtitle Pick and choose: Dealing with contrarians using dirty tactics is like a game of whack-a-mole.

At the heart of his statement is:

The majority of scientists follow the scientific method – a systematic approach to building knowledge. Starting in the 1820s, scientists began accumulating evidence, through the slow process of hypothesis testing and data collection, that adding carbon dioxide and other heat-trapping greenhouse gases to the atmosphere would warm the planet.

Now, after almost two centuries of research, scientists are as certain that human activity causes climate change as doctors are that cigarette smoking causes cancer.

On the other hand, many opponents of the scientific consensus on climate, like Tom Harris, author of the recent column Climate rhetoric undermines rational decision-making, and executive director of the International Climate Science Coalition, don’t need to play by the rules of science.

The whack-a-mole comparison was that rebutting one claim by “climate contrarians” gives rise to another, like a game of whack-a-mole. An ever repeating job and he got tired of it.

I heard these things before. More, it is something I myself believed before. In my believer years I thought that there was a invisible, powerful underground movement that employed dirty tactics against honest working scientists, making it difficult for them to make a dent with the public. Imagine my surprise when I found out that the debate was stifled by activists and political scientists who get almost exclusive attention in the mainstream media. By claiming consensus. By ad hominem attacks on skeptics. By making them look ridiculous/incompetant/unqualified. By not wanting to debate them on the science.

This opinion piece was specifically directed to Tom Harris. According to Donner, he made some ridiculous claims in an opinion piece “State of the Union climate rhetoric undermines rational decision making”, which are then demolished. No link to the article was provided, so I couldn’t check what Harris actually wrote. But Tom Harris himself had commented on the opinion piece of Donner and his arguments were well-thought and made sense. So this made me eager to find out who that Tom Harris was and why Donner had such a low regards of him.

Although I heard his name before, I could not recollect reading something from his hand. I became curious about what he really wrote in his article. I didn’t have to search long to find an article with the same title published beginning of February.

It confirmed my opinion on Harris. The article was about the use of rhetoric in the debate. Some terms in the debate can be misleading, for example “Carbon pollution” and “Greenhouse effect”. I heartfully agree with that. I also think that there are a lot of ambigue and misleading terms used in the climate debate, which make a genuine debate much more difficult. In the article Harris explained that “carbon” (a black, solid stuff) is not an accurate term when the real thing you want to describe is “carbon dioxide” (a transparent gas).

The reaction of Donner on this article was a bit weak. It focused on a couple sentences, ripping them out of context and then demolishing the “claim”.

The first rebuttal was the claim that Harris “suggests that carbon dioxide could not be a pollutant, because it is an invisible gas essential to plants”. That’s not even close to what Harris said. He did indeed say that carbon dioxide is an invisible gas essential to plants and he also said that it is a greenhouse gas and therefor has a (modest) influence on temperature. But he never said that is not a pollutant solely because it is essential to plants. Debunking an out-of-context claim is pretty easy.

Secondly, Harris claim that “Past ice ages demonstrate that climate change is normal” was countered by te statement that “the recent climate change is driven by human activity, and it is occurring at a rate not experienced in the history of human civilization”. While Harris was reacting on the Obama’s statement that “Climate change is a fact”. Of course it is. It has always been a fact and will always be a fact. The big question is how much our influence is within this change. In a situation were we only started with high quality measurements on the natural part a few decades ago, this could be more of a challenge than what Donner admits.

The last one was “global warming has been virtually non-existent during the past 17 years”. Donner claims that “the planet has not stopped warming” and that “during the past decade, more of that heat has gone into the deep ocean, due to natural cycles, so the atmosphere has not steadily broken global surface temperature records”. Well, that can be true, but this is still a hypothesis and not really supported by the observations, because there are not much observations of the deep ocean in the first place. And yes, there are some climate models that try to fill in the missing data. But model outputs are not observations, these are hypotheses that still have to be falsified. Nature is way more complex than the black/white vision of Donner.

Sigh. Dealing with these alarmist stories told with absolute certainty is as well like a game of whack-a-mole. 😉

But the conclusion was the most telling:

I agree. I’m tired of this game of whack-a-mole. We need to stop publishing the deliberately deceptive claims of contrarians like Harris, and get on with addressing the challenge of climate change.

Basically, we know everything we need to know, let’s shut down those who disagree with us and do the things we think we have to do. That is not a really a scientific way of thinking, but more an activist approach.

So not everybody plays by the same rules. That’s perfectly clear here, but now it is also clear which side doesn’t want to play by the rules and desperately want to stifle debate in order to do their own thing.

Pascal’s wager revisited

It is always interesting to find out how different people have different understanding of things. Recently I found a link to a video made by school teacher Greg Craven: A guy with a marker aims to make the global warming debate obsolete. The site that provided the link brought it as “an example of engaging and effective science communication“.

Well, that sounds promising!

According to the author it is possible to choose how best to act on the issue of Global Warming (he uses both Global Warming and Climate Change) without knowing something about the science of it. That is interesting. When I started looking at the global warming issue about five years ago, I also was searching for a way to find if the arguments about global warming were true or not. I found that in some cases this is possible (when certain logical fallacies were used), but in most cases it is necessary to know at least something about the science. I am a bit skeptical hearing him say no knowledge of the science is needed.

This is how it is presented: if we can’t be sure if global warming is true and we want to know what action to take, we can make a table in which we put the outcome of different possible scenario’s. On the left the question: “is Global warming true or false”? On top the question: “do we take significant action now”? From that outcome of these questions he claims it is possible to decide what is the best option to take right now.

Climate Change wager.

This is nothing new, I saw similar reasonings before. It looks very similar to Pascal’s wager. This says that “it is safer to believe in God, even if there is no proof that one exists”. Pascal’s starting point was also that it was not necessary to know something about the existence of God to know what do in our life. This is how Pascal saw it:

Pascal’s wager.

Pascal also wrote down the different outcomes of possible scenarios. These are the outcomes

If we believe and:
• God doesn’t exist: we lost some time worshiping and weren’t able to do things we probably would like to do → finite sadness (until we die).
• God does exist: we go to heaven and are rewarded for our efforts with eternal bliss → infinite happiness (forever and ever).

If we don’t believe and:
• God doesn’t exist: we didn’t loose some time worshiping and did everything we liked without restriction → finite happiness (until we die).
• God does exist: we go to hell and are punished with eternal misery → infinite sadness (forever and ever).

So if God exists, the reward and the penalty are huge (because they are forever). If God doesn’t exists, the reward and the penalty would be minor (because we have short lives). Therefor his conclusion was that it is better to believe in God because the outcome is better when we believe than when we don’t believe.

So far so good, but as I learned in school this wager is based on an array of logical fallacies and he cherry picked a bunch of assumptions that lead directly to this conclusion, therefor invalidating it. For example, in the wager Pascal assumed the God to be the God we know in this part of the world and that this is the “right” God. He also assumed that there is an afterlife and that believing in God is enough for eternal bliss and failing to believe will give eternal misery. Also that this God cares or is fair. That one can get away with calculated worship. Etcetera, etcetera. There are many others. A lot of books have been written about this wager.

As far as I know, the Craven’s wager has basically the same problems as Pascal’s wager.

It gives about the same outcomes as the Pascal wager. He adds that we can’t choose which row we want to be in, but we can choose in what column. He likens it with a lottery ticket. For example if we buy lottery ticket A then it will cost us a lot of money in both cases (we will ruin our economy whether global warming is true or not). But when buying lottery ticket B it is possible to have a rather nice reward if global warming is false, but a really nasty one if it is true.

Therefor he says that it is better to choose ticket A: we will loose money, guaranteed. But when we buy lottery ticket B, the outcome is much more uncertain: it is or extremely good (if climate change doesn’t exists) or extremely bad (if it does). So, if we want to avoid the extremely bad, we need to choose ticket A. In which we will have to pay a lot of money whether climate change is true or not, but if it is true we would survive it.

The author makes the suggestion for everyone to remake this for other outcomes (also the less extreme ones), but adds that whatever scenario you will choose, it will always come to the inescapable conclusion that ticket A will be better than ticket B…

But is this really true?

In analogy with the Pascal wager, this “inescapable” result is completely dependent on the smiley face in the bottom left quadrant; combined with the over-the-top dramatic scenario in the bottom right. If both scenario’s are taken as constants, the only sensible choice will indeed be ticket A. The over-the-top scenario of ticket B will overshadow the grim outlook of both scenario’s in ticket A. But I could imagine other scenario’s in which this is not necessarily the case and then ticket B might be much more interesting.

Let’s go through all quadrants and see what the range of possible scenario’s will be.

The only quadrant that we really can be sure of is the one on the top right. This means: we didn’t spend any money to prevent global warming, but it was not needed. Whatever scenario you choose, there will alway be a happy face in that quadrant.

The values in the three other quadrants will depend on the assumptions made and will be somewhere between the best case scenario and the worst case scenario.

In the top left quadrant he assumed: we spend money where it was not needed and we came into a (global) recession. That is the worst case scenario. The best case would be for example: we spend money, but we could afford it and spending it didn’t hurt us much.
All other options would be between those two.

In the bottom left quadrant he assumed that Climate Change existed, we took action and we came to the solution. That is in fact the best case scenario, not the worst as he assumes. Worst case would be: Climate Change exists, we did spend money on it trying to prevent it, but it didn’t work out (we spend it on the wrong solution, it wasn’t preventable anymore or whatever). In that case we would be with much less money and still facing the horrors of Climate Change. Like the victims of Haiyan who were unprepared for it.
All other options will be between those two.

In the bottom right quadrant he assumed that Climate Change existed, no action was taken and all the horrors of the world come at once and catapults us into oblivion. That is the worst case scenario. The best case scenario is that Climate Change exists, we took no action to prevent it and it was possible to adapt to it with not much effort.
All other options will be between those two.

Now we start all over and go for the two extremes (the real extremes, not the assumed ones):

• When we take the worst case scenarios in all cases, we will likely choose ticket A. So far so good. That was also the conclusion of the author
• But when we take the best case scenarios in all cases, we will likely choose ticket B.

In the end this exercise will learn us exactly nothing, except that the scenarios will depend on how one defines the assumptions for the different scenarios.

Just as the Pascal’s wager this wager it starts from a number of assumptions. For example that climate change is preventable by us, that we would be safe when we do something now, that the outcome of not acting is dramatic, that it is not possible to adapt and many, many more. Therefor the conclusion was skewed to ticket A.

This was a system assumed for those who have no knowledge of the science, but those are now presented with a one-sided presentation of the facts. But either way, my opinion is that when one starts from the premise that it is not necessary to know if global warming is true/false or if it is happening/not happening, then this table is useless to find out what the best option really is. Making this just a modern version of Pascal’s Wager, numerous assumptions and fallacies included.