Fair points.

I don't think I made the claim that our living in high CO2 environments means there are no ill effects. Yes, we are not dropping like flies. I truly don't feel it is an emergency that justifies wrecking entire economies to "save the planet" and other great sounding fake objectives.

I absolutely agree this should be the focus of further research as well as an awareness campaign. Modern building design (homes in particular) are seriously deficient on this front.

With regards to my outdoor readings, well, this is sunny California. There's a highway about a mile away. Not sure to what degree this might skew readings.

While taking readings I was very careful not to breathe on the thing. In fact, this is one of the first things I tested. It is incredibly sensitive, doubling the reading by breathing on it from a couple of feet away isn't all that difficult.

As to your third point, I am not sure I am implying that they make extreme claims. In fact, the conclusion they reach is almost a letdowns in the sense that there was no horror associated with exposing these poor animals to a CO2 level that the planet might not see for a century --if ever. My concern is that a bad study on 53 mice crammed into a box not much larger than a portable ice chest will now start to get quoted by those driving politically motivated narratives as yet another "the sky is falling" fake data point.

A proper study would attempt to look at two or more populations living in very different environments. Humans, that is. For example, study groups of people in both urban and rural areas in different parts of the world. A software developer in Los Angeles or NYC is exposed to far higher levels of CO2 concentration than, say, a rancher in Montana or a tribe in the Amazon. This, if done carefully, could provide us with important data from which to both take action at the individual level and drive sensible policy.

(5) The accumulation of CO2 by humans in the last century or two is very easy to explain and understand. For this you have to go back to ice core atmospheric sample data that is good for at least 800K years of accurate history. The accumulation --which usually took somewhere in the order of 25K to 75K years-- was due to, well, continental scale forest fires. Remember, no humans to do anything about it. Fires were probably far more of a normal reality than we might think today.

The record clearly shows that at a delta increase of about 100 ppm things started to reverse. The 100 ppm decline from there took about 50K to 100K years. Once again, no humans to "save the planet"...it just happened.

How? Rain, hurricanes, cyclones, storms and the massive regrowth of vegetation. The big sequoia trees are 2000 to 3000 years old. The time scale we are talking about represents 25 to 50 times that lifetime. It's hard to imagine.

Sadly, this data leads to a very simple conclusion: We cannot "save the planet" or affect change. At all.

Why?

Because the baseline would be if all of humanity left the planet tomorrow and all of our technology shut down.

We know precisely how long it would take to affect a 100 ppm reduction in CO2 if this were to happen: It would take 50K to 100K years. We know because we have data dating back to before humanity was able to make an impact. In other words, to be crude, anyone selling a solution is selling complete bullshit. There is no way anything LESS than leaving the planet is going to improve the baseline rate of change had if we all left the planet --the most extreme "save the planet" move.

This is a harsh reality. Solar panels, wind power, electric cars, not using fossil fuels, etc. Nothing is going to materially affect the path we are on. Not in one human generation. Not in a thousand. Can't happen.

BTW, I know of at least one paper where this conclusion was reached [0]. Interesting read because the researchers actually set out to show the world how renewables were doing to "save the planet". I admire the fact that they came right out and effectively said "we were mistaken".

What do to, then?

Well, we definitely clean-up our act. There's no reason not to. We can create better living environments. We just have to do it because this would be of benefit for other reasons (the cognitive issues you mentioned) within a reasonable human time scale.

Plant trees and stop mass deforestation. Not so simple, but this is something we can do proactively that will help. No, it will not stop CO2 accumulation in a human time scale. Yes, it should improve local conditions in this scale if done correctly.

What we should NOT do is anything in a list of hairbrained ideas being pushed for political or financial gain. From seeding beaches with chemicals to building city-scale scrubbers and killing entire economies by waging war against fossil fuels. These things range from pointless to dangerous. We are far more likely to kill all life on earth by pretending we can manage planetary scale problems than to do any good.

Going back to the kind of research I said could help. The question is very simple: If billions of us have been living in 1000+ ppm environments for perhaps a century or more (think buildings in the 1900's or earlier, no central air, etc.), is this our "normal"? If humanity has been doing well under these conditions, the doomsday scenarios being painted are likely false as can be.

Sure, there might be issues with these living conditions. And yet, this is how we have lived for a very long time. From the school teacher to the researchers who gave us the COVID vaccines, everyone is likely living and working in 1000+ ppm environments. I am not suggesting this is acceptable. I just don't know. What I do know, to repeat myself, is that, despite what we are being told, the sky doesn't seem to be falling.