The Definitive Global Climate Change (aka Global Warming) Thread — General Discussion and Questions
Here's a new data point. Record dry spell out here in on the West Coast. Now it's burning.
This recent paper by Benestad, et al, examines many contrarian papers (the ones outside the 97% concensus) and explains the errors in them. Perhaps the contrarians ought to now examine this paper to see if there are errors in the analysis?
I remember my professor made a similar argument 12 years ago or so in University…
What do we think? apologies if this has already been discussed or shown, big thread to get through!
…I see cycles have been brought up, starting from the first page 🙂
Not dead yet… Actually I have been in the midst of an extended relocation, hence my disappearance from this thread.
In any case, for those interested, the apparently imminent eruption of Mt. Agung on the island of Bali in Indonesia is potentially going to be globally important for climate in the next few years.
The last time Agung erupted was in 1963 and it resulted in a 0.1 to 0.4 C reduction in global temperatures over the next two years. In comparison, Mt. Pinatubo in the Philippines cooled things by 0.5C for 2 years after the 1991 eruption. It is uncertain how big this upcoming eruption will be as of yet.
In order for an eruption to become climatically significant it needs to inject materials (especially sulfur dioxide) into the stratosphere. In the tropics that means the eruption needs to push materials higher than 16 km. If the eruption height is in the 20-25km range then we will likely have globally significant effects on climate.
For a volcanic eruption to have global impacts it has to be in the tropics since equatorial eruptions can spread aerosols into both hemispheres. Unless we get a massive eruption (think Tambora in 1815 = Year without a summer) then the regional climate impacts will probably be relatively mild, though potentially nontrivial. Primarily over continental regions of the northern hemisphere, summers will be cooler (max effect at around 40 degrees latitude) while a stronger Polar Vortex will yield warmer winters for a couple years. If things mimic the Pinatubo eruption then most of North America, Europe and Siberia will be much warmer in the winter while Alaska, Greenland, the Middle East and China will be cold. The southern hemisphere sees less magnitude of impacts because of the relatively greater amount of ocean (releases heat), but the impacts last longer.
Within two years the eruption climate effects will appear to be over but there will be a sort of echo in the climate system that can last for decades caused by the cooling of ocean waters during the period when volcanic aerosols block some of the sunlight. This could help reduce the absolute rate of warming for a while but not enough to dramatically change our future climate projections from greenhouse gas warming.
By way of coincidence, I am supposed to be heading for Indonesia on unrelated matters next week….
Good to see you back, Mark, and good luck in Indonesia.
Maybe a few big volcanic eruptions close together will give us some respite. With news of recent research showing tropical forests are now a net source of emissions and that methane emissions from livestock are 11% higher than estimated, it seems like it's game over for humans versus nature. Nature will win, of course, but humans will have left their mark on it, perhaps for ever, if any nature survives. It's rather ironic that this research comes around the time that the latest estimates of emissions from energy show a continued stalling or slowing. We just can't stop ourselves from ensuring that atmospheric carbon continues to accelerate. This is because the environment always comes second to the economy for most people.
Oh well, it's oddly enthralling how we can't seem to help ourselves and even still have those who feel they need to pretend that there's nothing wrong or that what is wrong is easily manageable. I heard a fact twice recently, that I hadn't heard before: humans and their animals (for pets or food or other pleasure) now constitute 98% of the animal biomass on this planet, pretty much the reverse of how it used to be. Perhaps that illustrates just how f*d up we are.
Five years ago Mark made the claim “ “Predicting the climate is vastly simpler. “ (in comparison to predicting the weather)
I challenged him to live up to the standard he set for others regarding claims.
[quote=Me] To quote you…… "Stan, if you have any credible source(s) for this statement please provide it/them. Otherwise retract your assertion or qualify it as solely an unsupported opinion that you seem to hold regardless of scientific observations to the contrary."
Strike out Stan and insert your name….[/quote]
His response was this
[quote=Mark Cochrane] For global climate models however the analogy is the need to get the temperature right but you get to take the average of estimates for 30 years of 365 days each (give or take a few leap year days) at 5,000,000 locations. That is, you have about 55 billion attempts then you average them. The Law of Large Numbers (LLN) says that your difference from the mean temperature of the planet should be extremely small. [/quote]
His argument is equivalent to saying 'Predicting the climate is easier than predicting the weather because I saw a dog run over on the motorway this morning'
In one of my attempts to get him to see the illogic of his claim, I said
[quote=Me]The law of very large numbers, as I read in an explanation, applies to non dependent random events where all the possible outcomes of each occurrence of the event are known. [/quote]
(emphasis added here)
Marks responded with
[quote=Mark Cochrane] “”With regard to your questions on the law of large numbers (there are several, the weak, strong etc), we'd need a bonafide mathematician to parse the exact definition but I do not believe they only apply to discrete numbers or that all possible values must be predetermined. “”[/quote]
In his original claim he provided a link to a wiki page on LLN, ( you should be able to click on the link in his claim quoted above) and in it states what LLN applies to.
How he got from Wiki's definition to “ they only apply to discrete numbers or that all possible values must be predetermined.” I don't understand, and he provided no source backing such a definition.
and the first words in the wiki page are ""In probability theory, the law of large numbers (LLN)……." and probability theory deal with RANDOM numbers. ( So in a way he is claiming the output of the climate models is random!!!!)
Despite my attempts, Mark has so far been unable to see how logically flawed his claim is.
To date the 'score' for being able to see the illogic of his argument is roughly, believers 0% skeptics 100%
[quote=Mark Cochrane] Who am I and why should anyone believe what I have to say on this subject? Well, I post under my real name so any search engine will pull me up on top. I am a research scientist and professor with an environmental engineering degree from MIT and a doctorate in ecology from Penn State. I am what is termed an 'interdisciplinary' scientist which means someone who works across many scientific fields. This gives me a broader view than many of my colleagues on issues such as climate change. I teach graduate classes on the subject but also have taught it to middle schoolers, at open venues, a local church, and through newspaper editorials.[/quote]
I am gobsmacked that a person that said that of himself could come up with and defend such an illogical argument to back his claim.
It is not the only logically flawed argument he has presented in this thread, but it is certainly one of the most glaringly obvious.
How can he and his believers fail to see the illogic in his statements?
Who can see the illogic of his argument?
Without logic, you only have pseudo science……..
I missed this paper, last year, by Rockström et al, which outlines the challenge presented by the Paris Agreement goals. With no meaningful action to mitigate yet visible, it seems highly unlikely that we'll manage to meet even the weakest of those Paris goals.
The scale of the decarbonisation challenge to meet the Paris Agreement is underplayed in the public arena. It will require precipitous emissions reductions within 40 years and a new carbon sink on the scale of the ocean sink. Even then, the world is extremely likely to overshoot. A catastrophic failure of policy, for example, waiting another decade for transformative policy and full commitments to fossil-free economies, will have irreversible and deleterious repercussions for humanity's remaining time on Earth. Only a global zero carbon roadmap will put the world on a course to phase-out greenhouse gas emissions and create the essential carbon sinks for Earth-system stability, without which, world prosperity is not possible.
This discussion is quite good in terms of climate change overall, but the best part is actually an audience question at the very end where a researcher states that resource use efficiency is dropping at an annual rate of 0.8% and less than 0.1% of all material is recycled. When you top all of that off with moving away from fossil fuels to far less efficient alternative energy then you're really screwed: