The denialists have been moving the goalposts on these questions for the last 30 years. At first they strongly denied 1, but slowly they have been conceding on 1-5. Meanwhile their delay tactics have caused 6 to become more and more false. I suspect the 2000 election of Bush over Gore will go down as one of the most consequential elections in human history because every decade of delay will have effects for thousands of years.

But the fighting on steps 1-5 was so intense, every step of the way, and the character assassination against the scientists who advocated for them so consistent - I've lost a lot of respect for those responsible, including people close to me. It would be different if they were willing to consider possibilities and work together to find answers and solutions.

I more or less cut off contact with several people I used to consider intelligent and open to facts, but they were so blinded by their politics it became pointless to argue with them. I doubt anything will change their minds at this point, which is sad. It's one thing to debate the most appropriate response to this, it is another to deny the underlying physics exist.

> I think 1-5 is mostly settled,

Denialist still deny, generally, 3-5, and sometimes 2. Scientifically they may be settled, politically they are not.

6 is also essentially scientifically settled (we can't prevent it, we can probably reduce the rate at which things get worse, and may be able to limit the maximum effect.)

7 is either moot due to six or misphrased (there is a potential trade-off in the balance that goes into mitigating the severity of warming and that devoted to mitigating the severity of the consequences of warming without addressing the warming itself, but these are both forms of mitigation.)

8 is, again, moot because of 6, unless “prevent” is really “mitigate the severity of the warming”.

> the others are still open questions.

The bad news is that if we wait just a luttle longer, they'll become closed questions.

Why does anyone care whether it's caused by humans? If we knew an asteroid was going to hit the earth, it wouldn't matter that humans didn't cause it.

The reason it matters whether it's caused by humans is: mitigation. If global warming is significantly affected by our release of massive amounts of CO2, we could theoretically help mitigate the issue by stopping, and possibly reverse it. If on the other hand the rise of CO2 levels is not a significant factor, then there goes our primary idea to solving the issue.

That has nothing to do with who caused it.

You have asked a number of general questions here. Each question has a number of sub-questions that also need to be asked.

1). Is CO2 rising?

1a). What is the distribution across the planet and does this actually correlate to a general overall rise or is it more nuance than a simple rise?

1b). If CO2 is rising, is that a bad thing? What are the effects on the environment (both fauna and flora)? What are the actual detrimental levels beyond which fauna will be adversely affected?

1c). If CO2 was to be reduced, at what point is the acceptable limit? If it is reduced below that limit, what are the consequences on the environment (both fauna and flora).

1d). What are all the contributing factors to the CO2 rise (or fall, if it starts to head that way)? What factors can be influenced to change CO2 levels?

2). Is the planet warming?

2a). What is the temperature profile across the planet? Where do we measure these temperatures and how? Is there differences in the profiles with different measuring regimes? Are the temperature measurements made in odd places, like within cities but not the surrounding areas, etc.?

2b). What are the various factors that contribute to the temperature profile across the planet (seasonal variations, solar activity, city power usage, etc.)?

2c). Is there a up/down variation across years and/or decades that depend on how the statistical methods are structured (i.e. data manipulation of any kind)?

2d). Is there relevant data that is not used?

3). Is CO2 causing the planet warming?

3a). What are the various mechanisms under which warming will occur due to energy retention or generation?

3b). Are there other chemicals (such H2O, CO, NO, etc) that have a bigger or smaller energy retention effect?

3c). Are there other physical attributes of the planet that contribute to heating/cooling effects?

3d). Are there chemicals that ensure a lower retention of energy?

3e). What are the energy retention profiles of various chemicals with increasing concentration?

4). Is this due to human caused changes?

4a). What are the actual profiles of different human activities that cause either heating or cooling of the planetary surface and atmosphere?

4b). Are there geological phenomena that contribute to local or general heating/cooling effects?

4c). Are there heating/cooling effects due to other non-local phenomena (such as solar)?

4d). What are the actual profiles of these effects? Do some of the cooling effects offset the heating effects?

5). Will bad stuff happen because of it?

5a). Define what "bad stuff" means and with these definitions ask if there are multiple causes for defined "bad stuff"?

5b). How likely is this "bad stuff" to occur? Over what time period is it likely to happen? If the time period is extensive, are there other "good stuff" that can happen to alter the outcome?

5c). Is there other "bad stuff" that is more likely to occur that dramatically diminishes the effects of the originally defined "bad stuff"?

6). Can we actually prevent it?

6a). What are the various prevention methods and what are the pros/cons of each methodology?

6b). Are any of the prevention methods actually feasible?

7 and 8 are sub questions for 6.

In relation to 1. The detrimental effects of CO2 on fauna occurs at a level about 20 times the current promulgated level. The detrimental effects on flora begin when levels are reduced about 1/4 of the current levels. The beneficial effects of increasing CO2 levels on flora are seen by many horticulturists and various research programs that are currently running around the world.

In relation to 2, this seems to depend on the methodology in used by various groups. Even if it is, the effects of even a 2 degree increase worldwide hasn't been detailed with any sort of accuracy yet.There have, of course, been many claims of disaster scenarios, but the driving energy for those scenarios has been conspicuously missing. I am still wondering why.

In relation to 3, there are many nuances here that are not being discussed.

In relation to 4, there are many who are "true believers" in this view, but the detailed evidence is sparse. This needs a great deal more investigation. It may well be true, but based on the wide variety of causes, we still have no clarity about the processes.

In relation to 5 and 6, much has been claimed, but little is logically presented.

The rhetoric needs to stop and the partisanship needs to diminish, so that we can do real actual research into the entire subject. It has become so politicised that we cannot separate the wheat from the chaff.

It is also interesting to note that many who promulgate the idea that climate change is predominately anthropogenic and deliver disaster scenarios as if they are certain and call for all people to restrain themselves, do not themselves do anything to restrain their own influence. It becomes a case of "do as I say, not do as I do." This occurs from the senior figures right down to the little angry followers.

What can you say, what can you do but shrug your shoulders?