CO2 is plant food, the basis of all life on Earth. CO2  is not a pollutant. It is essential to all life on Earth. Photosynthesis is a blessing. More CO2  is beneficial for nature, greening the Earth: additional CO2 in the air has promoted growth in global plant biomass. It is also good for agriculture, increasing the yields of crops worldwide.

Ok, probably none of those that are scientists are biologists, but you'd have thought some would have a basic understanding of biological and ecosystem processes. But anyway that's not the point. This paragraph (and it's a very short letter so no-one can claim it's "out of context") has nothing to do with climate change one way or another. It's just weird. Any scientist that tried putting that in a climate science paper would be laughed out of the room - not for challenging the status quo, but for having a "scientific approach" that would be unacceptable even at GCSE level. You could say the same about water, essential to life but too much of it is going to cause problems...


As various websites have pointed out, this letter is the same old arguments rehashed. Yes, climate scientists know that the models aren't perfect, and produce differing long term results. It doesn't affect the fact that they show common trends.


Probably a hint as to what happened here is - to pick an example - that one of the 500 was Richard Lindzen. Now he does know what he's talking about, but what's key is that he describes himself as a "contrarian". He likes to provoke debate. Which is fine - except that the time to sit around chatting about the theoretical watertightness of the Titanic's chambers is when it's being designed and built, not when it's going down. I suspect  (although I don't know, people could check if they wanted) that several more of the signatories are similar old-school academics who enjoy a good academic common room contrarian debate. The question is whether they are taking on board the effect on society of the way they are having the debate - chances are they'd say that's not their problem. Personally I'd disagree.  


Given we don't really know why these 500 people chose to sign this letter I'm not sure this is likely to turn into a very helpful discussion on this forum. But anyone interested in what type of arguments are being crafted to appeal to climate change deniers would profit from reading this letter. (I suspect, from the CO2 references, it's largely a fossil fuel lobby focused item.) But don't read it expecting to learn how to present a scientific argument to anyone who understands science!



What concerns me more, because it is my field (whereas atmospheric physics isn't), is the misunderstandings about risk management in all this. Let's say (crudely, and people can disagree with my figure but I'd argue the order of magnitude is correct) that 95% of scientists who understand the mechanisms involved believe that the climate will significantly change due to man made effects - even if they can't accurately predict exactly in which way it will change. And let's say that if they're right then there will be considerable loss of life. Then any credible risk management process says that you put that into a matrix, the probability of occurrence will go in as high (not inevitable, because some relevant scientists disagree, but most don't) and the related consequence will be severe. That comes out with the conclusion that you must do something to reduce your risk.


In most countries you are not allowed legally (or, I'd suggest, morally) to say that a bridge is ok if 95% of your engineers say it is going to collapse with significant loss of life and 5% say it's fine. You have to do something about it. The fact that as MD of the construction company you don't understand the arguments of 95% of your engineers ("but I can see it standing, I walked across it this morning and it was fine") will be, quite rightly I'd argue, no defence when it collapses.



I don't plan to debate this any further here as I have no evidence that any of us are experts in climate science, and I think this subject is too serious for a banter level debate (see my comments above on Richard Lindzen). I am sure other institutes (e.g. IoP?) have forums where they do have that expertise and would be able to accommodate such a debate.


Andy

CO2 is plant food, the basis of all life on Earth. CO2  is not a pollutant. It is essential to all life on Earth. Photosynthesis is a blessing. More CO2  is beneficial for nature, greening the Earth: additional CO2 in the air has promoted growth in global plant biomass. It is also good for agriculture, increasing the yields of crops worldwide.

Ok, probably none of those that are scientists are biologists, but you'd have thought some would have a basic understanding of biological and ecosystem processes. But anyway that's not the point. This paragraph (and it's a very short letter so no-one can claim it's "out of context") has nothing to do with climate change one way or another. It's just weird. Any scientist that tried putting that in a climate science paper would be laughed out of the room - not for challenging the status quo, but for having a "scientific approach" that would be unacceptable even at GCSE level. You could say the same about water, essential to life but too much of it is going to cause problems...


As various websites have pointed out, this letter is the same old arguments rehashed. Yes, climate scientists know that the models aren't perfect, and produce differing long term results. It doesn't affect the fact that they show common trends.


Probably a hint as to what happened here is - to pick an example - that one of the 500 was Richard Lindzen. Now he does know what he's talking about, but what's key is that he describes himself as a "contrarian". He likes to provoke debate. Which is fine - except that the time to sit around chatting about the theoretical watertightness of the Titanic's chambers is when it's being designed and built, not when it's going down. I suspect  (although I don't know, people could check if they wanted) that several more of the signatories are similar old-school academics who enjoy a good academic common room contrarian debate. The question is whether they are taking on board the effect on society of the way they are having the debate - chances are they'd say that's not their problem. Personally I'd disagree.  


Given we don't really know why these 500 people chose to sign this letter I'm not sure this is likely to turn into a very helpful discussion on this forum. But anyone interested in what type of arguments are being crafted to appeal to climate change deniers would profit from reading this letter. (I suspect, from the CO2 references, it's largely a fossil fuel lobby focused item.) But don't read it expecting to learn how to present a scientific argument to anyone who understands science!



What concerns me more, because it is my field (whereas atmospheric physics isn't), is the misunderstandings about risk management in all this. Let's say (crudely, and people can disagree with my figure but I'd argue the order of magnitude is correct) that 95% of scientists who understand the mechanisms involved believe that the climate will significantly change due to man made effects - even if they can't accurately predict exactly in which way it will change. And let's say that if they're right then there will be considerable loss of life. Then any credible risk management process says that you put that into a matrix, the probability of occurrence will go in as high (not inevitable, because some relevant scientists disagree, but most don't) and the related consequence will be severe. That comes out with the conclusion that you must do something to reduce your risk.


In most countries you are not allowed legally (or, I'd suggest, morally) to say that a bridge is ok if 95% of your engineers say it is going to collapse with significant loss of life and 5% say it's fine. You have to do something about it. The fact that as MD of the construction company you don't understand the arguments of 95% of your engineers ("but I can see it standing, I walked across it this morning and it was fine") will be, quite rightly I'd argue, no defence when it collapses.



I don't plan to debate this any further here as I have no evidence that any of us are experts in climate science, and I think this subject is too serious for a banter level debate (see my comments above on Richard Lindzen). I am sure other institutes (e.g. IoP?) have forums where they do have that expertise and would be able to accommodate such a debate.


Andy