[_y5hn]

Possibly, but click on the button on upper left: Show last 800,000 years

Including 0 on the graph could be misleading too.

Page 8 of this report shows for millions of years together with explanations of some extinction events:

http://burro.case.edu/Academics/USNA229/impactfromthedeep.pd...

"If this trend continues, by the end of the next century atmospheric CO2 would approach 900 ppm—just below levels during the Paleocene thermal extinction 54 million years ago."

[incrudible]

> "If this trend continues...

That's my point. It won't continue. Nothing grows to infinity. CO2 levels are rising due to an increase in emissions year-over-year. This increase is guaranteed to stop on its own. We don't know what happens if emissions stabilize at current levels. Perhaps CO2 concentration will continue to rise for a while, perhaps it will stabilize rather quickly. Absent any other factors, the long term trend is always for CO2 levels to (slowly) sink.

If I naively extend the following correlation, just going from 420 to 520 would require adding another 30 Gt of CO2 of annual emissions (almost doubling current levels):

https://www.climate.gov/sites/default/files/CO2_emissions_vs...

That amount represents the economic jump from the 1950s to now. Not inconceivable, but also not foregone.

> ...atmospheric CO2 would approach 900 ppm—just below levels during the Paleocene thermal extinction 54 million years ago"

Name-dropping an extinction event in this context is rather unwarranted, considering that those 900ppm were preceded by a slow descent from 1500ppm.

[_y5hn]

Was looking at this one: https://en.m.wikipedia.org/wiki/Triassic–Jurassic_extinction...

Lots of countries are looking to go from 1950's economy to modern standards, many live in rural areas that develop etc.

Why do you believe CO2 tends to drop? The accumulated CO2 don't follow emission drops in the graph. CO2 may linger for decades to hundreds of years.

Humanity is driving faster downhill without any brakes.

[incrudible]

> Was looking at this one: https://en.m.wikipedia.org/wiki/Triassic–Jurassic_extinction

Same problem, you're name-dropping an extinction event which has, at best, a speculative relation to climate change in general and CO2 levels in particular. Certainly you will find such events where changes in CO2 coincide with extinction, but you will also find events where they don't.

> Lots of countries are looking to go from 1950's economy to modern standards, many live in rural areas that develop etc.

That is true and I'm not ruling it out, but that then begs the question what difference (if any) the comparably small population of already developed countries could make by curbing their emissions.

> Why do you believe CO2 tends to drop?

The cycles of the past million years. After every sudden peak, CO2 levels drop... until the next peak.

> The accumulated CO2 don't follow emission drops in the graph.

For one, there have been no sustained drops in emissions. Secondly, these graphs have different smoothing functions applied to them. Still, they do track each other pretty closely. Around the time of WW2, you see several years of constant CO2 levels, despite increasing cumulative emissions.

> Humanity is driving faster downhill without any brakes.

That's the mental image you like to use. I like to use this one:

https://nolanlawson.github.io/fronteers-2016/img/discostu.jp...

[_y5hn]

What would make CO2 drop though. Acidification of oceans? Those CO2 peaks mark descents into Ice Ages and cataclysmic events during millions of years.

[incrudible]

Sequestration, basically. All of those fossil fuels we burn today have at one point not returned into the atmosphere. An increase in CO2 also leads to an increase in vegetation. Ocean acidification is a concern that I can't dismiss, but that's true of many concerns and I can't cater to them all.

> Those CO2 peaks mark descents into Ice Ages and cataclysmic events during millions of years.

I was referring to the interglacial cycles, these are not cataclysmic per se.

https://www2.atmos.umd.edu/~zeng/papers/Zeng03_glacialC.pdf

As for the descent into an ice age, according to the interglacial cycle, we were right on schedule for that. Perhaps our ancestors will thank us for averting it?

[_y5hn]

Hard to say or to rule this out as well.

https://principia-scientific.com/why-the-current-interglacia...

https://climate.nasa.gov/news/2948/milankovitch-orbital-cycl...

Anyways, seems humanity is going into very intense periods going forward.