Great points and I think you're spot on.

I'm personally a skeptic of the claims made by the AGW side and the alarmism pushed out by so many. The proposed AGW solutions are not feasible worldwide either which is what would be necessary to solve the problem they outline. I'm saying this not to get into a discussion about it at this time but to lay out why I would STILL support the agenda: essentially there are several great secondary benefits from doing what they recommend.

This is the biggest failure of the AGW side - they have terrible positioning and think you're stupid if you question science. If you tell people they're stupid (even if they are) they aren't changing their minds.

This is how you push the AGW agenda. "Let's say we're wrong. Here are the benefits of doing what we're suggesting and making some changes & investments":

- Better air quality

- It's good for national security - we no longer need to send large sums of money to hostile countries, many of which support terrorist organizations and other groups which are Anti-American / Anti-Western values.

- Cheaper energy

That's hard for anyone to argue, assuming the legislation is sensible.

That argument is already being made, if people were open to this line of reasoning they would have heard it a long time ago.

I think the longer term and overarching issue is that we don't have a shared reality. Science is not a method of finding truth for a large proportion of the American electorate. Academia, scientific institutions, and journalism might as well not exist if people don't believe in them.

If that's the case, then it's requires a much more in depth answer than "well look, we might do some good if we spend billions in (perceived) cost". I don't have the answer and perhaps there isn't one.

> The proposed AGW solutions are not feasible worldwide either which is what would be necessary to solve the problem they outline.

Just to pick out this point, I don't agree, I think actually most of the action to reduce emissions will be profitable. Low energy lighting pays its investment back in 6 months, on a ten year lifetime. Electric cars are significantly cheaper than petrol already in many countries and particular situations. Solar panels are similarly on the verge of profitable in high insolation, high energy cost places. Both are seeing continual reductions in cost, which will open up new markets, which will lead to economies of scale, which will reduce cost. And there are a lot of situations like housebuilders not putting in decent insulation, because they don't pay the heating bills, where good information can again provide the opportunity for investment with an amazing return. A large amount of the necessary reduction is not difficult, once you properly direct the market economy and industrial civilization against the challenge.

You have a pretty good understanding of the issue however you're either unaware or omitting one important fact.

Much of the friction in left v. right issues tied to science or "science" is that in recent decades the Science Community has produced and condoned a wide body of junk science through poorly-designed studies, slavish worship of the P value, outright industry-based lies, corrupting control groups with non-inert placebos. All relying on a sacrosanct Peer Review system wherein it is impossible to find capable reviewers that are not tainted by industry money. Not even at the university level. Add to that several editors of prestigious journals like NEJM and The Lancet coming forth and saying "half of what was published in my journal was crap". Don't forget all the scientists who support this system through silence, coerced by their fear of losing their jobs for challenging the "science" published by their employers.

In short, the Science Community has created what appears to many as an insurmountable problem of credibility and integrity. In other words, no such "I believe the science" assertions will be forthcoming from climate change deniers. Maybe if the Science Community as a whole can divorce itself from its numerous conflicts of interest and excoriate and excise the junk from its current offerings.

I'm a strong advocate of science and the scientific method, and I think much of what is labeled as "Science" should more appropriately be labeled "Propaganda". I've read plenty of stuff that a 6th Grade Science teacher would easily call out for violating the fundamentals of the Scientific Method. Add a little quid-pro-quo with your peer reviewers, and voila, study published in prestigious journal. Career advancement.

I'd wager a trivial percentage of the people who refuse to accept climate change would actually (credibly) use any of those reasons. They might parrot them because it's a talking point now, but ask them to explain the problem of p-value misuse.

Probably similar on both sides of the debate. Does Al Gore understand p-value misuse? Probably. Bill Nye? Not so sure.

Yes focus on the P value and ignore a system of science that has no independently-funded researchers.

People who are turned off by Al Gore's name on it aren't going to say "now that the evidence is in, I support reasonable action" if presented with the same thing without it.

In some sort of abstract experiment, where you take hypothetical voter A and show them hypothetical non-partisan movie B, I'm sure it could easily make or break it. But in the real world, where you take Fox News watching, New York Times hating, Rush Limbaugh listening, Republican voter A, and show them "non-partisan" climate change activist movie B, they're going to be told that it's all part of the vast liberal conspiracy before the movie is even available, and they'll hate it no matter what.

When Republicanism has climate change denial as one of its fundamental beliefs, the only way to get people to abandon climate change denial is to get them to abandon Republicanism. And you can't get them to do what without being forced to admit they are actually changing their minds.

>> At some point a significant proportion of the people who have been ridiculing climate change ... will shift their beliefs to accept moderate action to tackle climate change...

what makes you so sure of that (assuming by 'climate change' you mean 'anthropogenic global warming') ?

Because a significant percentage of anthropogenic warming is down to the direct heating effect of CO2, and the positive feedback of that direct heating raising evaporation of water, and the direct heating effect of water. i.e. it's based on simple calculations from core scientific principles. If there's going to be no effect, it requires some negative feedback effect which is not adequately described. So there is a baseline of warming which is very likely to occur, and over time that kind of evidence of rising temperatures becomes undeniable.

>> anthropogenic warming is down to the direct heating effect of CO2...

OK, let's say this was the case. First question - what percentage of CO2 in the atmosphere is attributed to human activity?

We've increased it by about 50% since the industrial revolution, from about 280ppm to 410ppm. You can tell both from isotope analysis and inventory studies most of the ongoing excess is down to humans.

Also, I'm not sure what in that statement is even up for debate, does anyone question that a concentration of CO2 in a volume of space absorbs light at particular wavelengths? It's core science, and a straightforward calculation.

That's not what I asked. If total CO2 in the atmosphere is 100%, what portion of that number is attributed to human activity? Also, CO2 itself - out of all of the greenhouse gases in the atmosphere - what percentage belongs to CO2?

How is that not what you asked? If we've increased the amount by 50% over preindustrial levels, then the current portion attributable to us is about 33%.

...except that figure is less than 4%. about 8 gigatons are attributed to humans out of ~220 gigatons injected into the atmosphere overall on a yearly basis.

the kicker is - the percentage of CO2 in the overall greenhouse pool is also in the single digits, the most significant (volume-wise) greenhouse gas which comprises about 95% of the greenhouse gases in the atmosphere is water vapor.

so if you factor that in - if humanity ceases to exist tomorrow, there is a potential for a .3% change in greenhouse gas volumes.

> ...except that figure is less than 4%. about 8 gigatons are attributed to humans out of ~220 gigatons injected into the atmosphere overall on a yearly basis.

This is like the difference between profit and savings. Accumulated CO2 is a savings accounts, and the pre-industrial climate in the short term acts like a business which has zero profit, balanced revenues and expenditure. If you come into the business, and hold expenditure the same, but increase revenues by 4%, and yield a 4% profit, which every year you put in the bank account, that is going to accumulate over time. And the warming is created by the accumulation. You talk about a 4% yearly excess as if that was a small amount!

Also, your point about water vapour ties into what I said in the earlier comment, a lot of the warming is exactly that secondary effect - CO2 has a direct heating effect, that raises temperature, which then raises the partial pressure of water vapour, which increases concentrations of water vapour in the atmosphere, which as you say is a very important greenhouse gas. It's the combination of these two effects, of direct CO2 warming, causing increased water vapour concentration, which accounts for the baseline warming which everyone who is sceptical of computer models should believe in. This very well-established baseline warming accounts for about half of the climate sensitivity proposed by the IPCC, if you think computer models are junk, that discounts many of the positive feedbacks proposed, but also the negative feedbacks which would have to exist, to lead to zero warming.

>> You talk about a 4% yearly excess as if that was a small amount!

This analogy would only make sense if somehow this 4% wasn't spent or was spent differently than the rest of the money. Also don't forget we're talking .3% if you take all of the greenhouse gases into consideration.

>>...if you think computer models are junk, that discounts many of the positive feedbacks proposed, but also the negative feedbacks which would have to exist, to lead to zero warming.

This sounds like mental gymnastics trying to single out the evuuhl CO2. Given the fact that planet Earth went through multiple heating/cooling cycles way more severe than the current warming trend without any antropogenic influence, applying Occam's razor here would lead me to believe the issue lies elsewhere.

If you want to just examine emissions, humans have emitted about 1.5 trillion tonnes of CO2 since the industrial revolution, and the atmosphere contains about 3.2 trillion tonnes of CO2 in total. So if you go by that reasoning, we're responsible for about 47% of the total.

that's not apples to apples. how much CO2 was naturally emitted in that timeframe? that would be an apples-to-apples comparison.

So you understand that the amount emitted over time is not equal to the amount currently present? Why, then, do you compare emissions when your question was about the amounts currently present?

>> So you understand that the amount emitted over time is not equal to the amount currently present?

I do, but you don't seem to since you came back with an attempt to quantify the "amount emitted over time"

my question was: >>> what percentage of CO2 in the atmosphere is attributed to human activity?

...and I even answered it myself :) ... it's ~4%

Your 4% number is also based on emission rates. My number and yours are both nonsense for the same reason. You can't make the attribution by looking at emissions alone.