What is not under debate

[Barney]

I have taken a hiatus from investigating climate change arguments. Plumbing the depths is rather time consuming and I feel I emerge after hours of digging to confirm or deny one small brick of a giant castle. Emerging with the result that the “hockey stick” is fake and why took the better part of a weekend (to be fair it was not ‘faked’, it is the result of a statistical treatment of data by non-statisticians that resulted in a trend they were pleased with. The statisticians pointed out misuse of the statistical treatment and showed that if the same treatment was applied to noise one could consistently obtain similar results, indicating that the “signal” they were supposedly recovering was not different from noise.).
For reference here is the original “hockey stick”

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A more streamlined approach may be to identify what is not contested. I think this may actually be more directly revealing because the media portrayal seems to straw-man climate change deniers as though they deny science. I think the truth lies more along the lines of simply denying the mainstream narrative, that is to say journalist coverage and rejecting the message that we need to panic.

• CO2 is increasing:
  I have not seen any challenge to the data represented below. It is agreed that CO2 is increasing.
  

  

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• The increase in CO2 is at least partially caused by the burning of fossil fuels (how much is under debate but I think it is generally agreed that this big upward trend is mostly us)
• Water vapor is by far the biggest greenhouse gas

  

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• CO2 has a logarithmic warming effect, meaning that the impact of increasing CO2 decreases, illustrated below.

  

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• Higher CO2 levels are beneficial for plants especially in very dry areas and we are currently seeing a greening of the earth (CO2 fertilization effect) https://www.nasa.gov/feature/goddard/20 ... ning-earth
• The earth is warming slightly but pay special attention to the scale on the y-axis. The exact forms of this reconstructed temperature vary widely but it is generally agreed that the “current” (i.e. since 1700) trend is warming.
  

  

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• However, recent (20 years) temperature trends are slight cooling
  

  

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• All dire predictions are based on climate models being projected into the future and which everyone admits are fraught with uncertainty. For example ocean currents, solar variation, cloud cover and many more, currently are not modelled because of the difficulties. This casts significant doubt as to their accuracy despite that they are the best we have. Proponents of the models will say they are the cutting edge science (true) and therefore should be trusted (maybe), detractors will point out the shortcomings (also true) and say they are not to be trusted (maybe).

[Barney]

Water vapor is by far the biggest greenhouse gas

There are a few problems with this chart that need to be addressed:
1. What is its date?
2. The important question is not how much of the gas there is but how potent its warming effect and how long it hangs around in the atmosphere. Water vapour, although we don't give it off (apart from plane trails) is increased by the global warming effect and so can't necessarily be framed as a 'natural' thing that we can't take credit for.

Also see this video: https://www.ted.com/talks/kate_marvel_c ... ate_change

I'm not quite sure what you are debating. You are free to refute the claim. I don't think there is evidence to the contrary. The things I have put here are things I have found agreement on.

[Barney]

For example ocean currents, solar variation, cloud cover and many more, currently are not modelled because of the difficulties. This casts significant doubt as to their accuracy despite that they are the best we have.

Note that this graph only applies to US and ends in 2016. A lot of the media headlines say that the recent 5-10 years have been among hottest on record. It would be interesting to see an updated graph which looks at average global temperatures and see what trends it shows.

I am very wary of statements like "among the hottest on record". If the warming trend shown on the previous plot from 1700 to 2000 reversed going forward in a perfect mirror we could say for the next 300 years that that year was among the hottest on record. despite a 300 year cooling trend. It's especially easy to hype stuff up without outright lying.

Looking at this chart and moving into the mindset of let's say this was my data that I took from a sample. I would say it is utter nonsense to put that trend line on it and make any claims whatever. We are talking about a variation of 0.25 C over ~20 years and a substantial spread in the data. However, I think the point of the trendline is to show that you cannot say it is going up.

But in any case, this isn't the result we want to find. The solution is to keep looking and inventing new ways to look at the data until we DO find the result we want to find. I mean, we know without a doubt that global warming is true and this chart doesn't fit that knowledge. So we know that it is being misleading somehow. We're just not quite sure how. What we need is an expert who can set us at ease that such things can be ignored.