A cool nerdy video about Global Warming

A.k.a. Pascal's climate change wager.

Turns out that was the very first criticism he addressed. So much for me being clever :p

This argument is very weak. And I do fully accept the reality and danger of global warming.

In the first column the smiley needs to be removed from the is-it-real box. I hope the reason is obvious: if action would cause a depression if global warming is false, then it will cause a depression if global warming is true. This makes it 100% chance, if we accept this reasoning, for a bad result unlike the second column (do nothing) which we have a chance for a good outcome. Indeed doing nothing is our only hope to avoid catastrophe if this chart is to be accepted.

Another obvious problem is that one can simply replace "Is global warming true" with any piece of nonsense and the reasoning is the same. Thus by this guy's reasoning we need to take action against any alleged disaster of the magnitude that climate people are predicting. The only way around it is to try and determine what row is more likely and that destroys his entire point. The science is in. Global warming is overwhelmingly probable. This means in practice this chart should only be row 2 and thus a choice between depression (if we take action) and horrible natural disasters that will cause a depression and other ills (if we don't take action).

And of course I don't accept the premise that taking action will result in a depression either: thus it is a choice between some economic cost and catastrophe. So really really we need a third dimension to this chart for "can we afford to act".

Mike, the depression was a worst possible outcome if we reduce emissions and there turn out to be no global warming, not the most likely one. In the other square with global warming he used the most likely consequence, which is no depression. One can even argue that even the more modest global warming we get in that scenario will force so many adaptations to be made that it will pull us out of any depression, just like WW II pulled us out of the big depression. Wars and disasters have many disadvantages, but they do create work.

Aftergone through this blog i am very impressed. But I am also write some information about Global Warming.

Mike, the depression was a worst possible outcome if we reduce emissions and there turn out to be no global warming, not the most likely one. In the other square with global warming he used the most likely consequence, which is no depression.[snip]

Which is B.S. The economic costs of taking action will not be smaller if, global warming is real. Nature does not give us refunds. (Any bad consequences of global warming are solely in the second column in this guy's analysis.) If a smile belongs in the bottom-left square then it must also belong in the upper-left square. He pulled a fast one.

And as I pointed out, since he is not willing, in this analysis, to use the actual evidence and since some think we can take action with little economic harm and some think it will be the worst depression then we really need a third dimension for this analysis: the affordability of the action. If we can afford to take action then we have very little to lose by taking action. But if taking action does have a cost of creating depression and taking action give us a 100% chance of disaster.

And none of this is as bad as his wanting to ignore row decisions and only focus on the column. The science is strong enough to say we are on the bottom row. If we don't ignore that reality then the choice is between the economic cost of taking action and what will undoubtedly be far worse economic (and other) costs of not taking action. (Not to mention that if the global warming consequence happen, action far more drastic and economically harmful will begin.)

And if we do ignore that global warming is true for such an analysis, then we must be consistent and do the same for all alleged potential disasters. And by the presenter's reasoning (if we accept his reasoning) we will will have to take action against them all no matter how ridiculous they are. If you say that [fill in the blank tin-foil hat "theory"] is clearly wrong then it is an admission that we really should evaluate the validity of the claims in the rows which violates his whole premise.

:-) Great example for the psychological phenomenon of risk-aversion:
http://en.wikipedia.org/wiki/Risk_averse

This guy is trying to do a simplified risk ( or cost) analysis. You calculate a cost for each action and estimate a probability of each possibility ( global warming vs. no global warming). You then calculate the total weighted cost ( probability * cost) of each column.

You don't need super accurate values to do this. Order of magnitude should do it. Figure some rough magnitudes of the cost and some rough probabilities of the two events.

BTW - I agree that global depression belongs in both boxes. But global depression also goes into the "global warming/ do nothing box".

And there are some positives in the "no global warming/ do something" box - such as higher energy efficiencies and technologies we can sell to the rest of the world.

Anyway, through in your own probabilities and cost, sum up on the columns, and decide what you would do.

I can say that if the probability of GW is at least 50%, it is definitely best to take action.