Dear Josephus,

You asked;

"SteeleRedux,
post the name of one reputable scientist in Earth science who has public papers that demonstrate CO2 harms the planet; and humans currently cause climate change other than by Earth previous natural history. "
Sure.

"Earth science encompasses four main branches of study, the lithosphere, the hydrosphere, the atmosphere, and the biosphere, each of which is further broken down into more specialized fields."
Wikipedia

James Hansen

"James Edward Hansen (born 29 March 1941) is an American adjunct professor directing the Program on Climate Science, Awareness and Solutions of the Earth Institute at Columbia University. He is best known for his research in climatology, his 1988 Congressional testimony on climate change that helped raise broad awareness of global warming, and his advocacy of action to avoid dangerous climate change."
http://en.wikipedia.org/wiki/James_Hansen

Josephus,
My deduction was correct. The Greenhouse Effect is not synonymous with global warming; it's an ongoing phenomenon that has affected this planet since its formation.

Before we go any further, I just want to make it clear that the Greenhouse Effect does not work the same way as an actual greenhouse. Those work primarily by stopping the heat being carried away by convection, whereas the Greenhouse Effect works by absorbing and reemitting radiation.

Warm objects emit infra red. The warmer they are, the more they emit.
The sun emts a broad spectrum of electromagnetic radiation, including infra red, visible light and ultra violet. When these reach the ground, they are (largely) absorbed and heat it up..
When the sun heats up the ground, the ground emits more infra red
Therefore there is more infra red radiated out to space from the earth than it receives from the sun.
Greenhouse Gases (like CO2) absorb infrared and reemit it in different directions. Because most of the infrared is going upwards to start with, the greenhouse gases result in more of it going downwards, warming the planet again.

Please note that the above is a simplified explanation so that you can understand what's going on and why CO2 has a warming effect. If you think of something I've omitted, DON'T assume the climatologists aren't already well aware of it.

BTW, CO2 is actually a pretty weak greenhouse gas - over 99% of the infra red goes straight through it without being absorbed. However it's much more prevalent in the atmosphere than other greenhouse gases, so aside from water vapour, CO2 has the most effect on the atmosphere. Water vapour quickly condenses out, so its role is mainly as a feedback mechanism: the warmer the atmosphere, the more water vapour it can hold before it condenses.

>In the largest cases, a single volcanic plume, lasting only hours, might
>add many millions of tons of carbon dioxide to the atmosphere.

Have a look at http://www.abc.net.au/news/2019-03-26/global-carbon-emissions-hit-record-high-in-2018-according-to-iea/10941378
Humans were responsible for emitting 33.1 billion tonnes of carbon dioxide into the atmosphere last year.

Hi Aidan,

"Humans were responsible for emitting 33.1 billion tonnes of carbon dioxide into the atmosphere last year."

And how much is taken up annually by the environment, naturally ? What's left over that we have to deal with ? And why not deal with much of it by re-forestation and other productive uses ?

Cheers,

Joe

Hi Joe,
>And how much is taken up annually by the environment, naturally ?
Currently about half.
http://www.vice.com/en_us/article/wjmqwb/plants-are-losing-their-capacity-to-absorb-human-co2-emissions

What's left over that we have to deal with ?
The other half.

>And why not deal with much of it by re-forestation and other productive uses ?
Why not indeed? That's much harder than it sounds, though, as reforestation requires a huge amount of water. Also, for long lasting CO2 removal, we have to prevent the natural decay process from putting that CO2 back into the atmosphere. Contrary to what Josephus claimed, the reason there's so much coal in the ground is nothing to do with volcanoes - it's thought to be that there was a long gap between the time plants evolved lignin production and the evolution of the fungi that consume lignin.

Considering the heating effect increased CO2 is having on the planet, your simplistic assumption that more of it is a good thing is dangerously wrong. Sure it's essential for life, and nobody's claiming otherwise, but that's irrelevant as nobody's suggesting eliminating it. The current level of 415ppm is no better for animal life than the preindustrial level of 280ppm. And it's only slightly better for plant life. Don't make the mistake of asking it to be directly proportional - the plant's certainly aren't growing anywhere near 50% faster!

As for coral, more CO2 in the water would make the calcium carbonate more soluble, as more of it would be in the form of Ca(HCO3)2 instead. But coral bleaching as a result of sustained heating is a much more urgent problem for the reef.

Hi Aidan,

Re-forestation needs a lot of water; which could be provided from rivers and desalination plants along the north coast, powered by nuclear energy, perhaps from thorium. Yes, it would cost a hell of a lot, but so does every other 'remedy'. Of course, it may not remove all of the CO2 from the atmosphere but it may contribute substantially. And more or less pollution-free too, to use the latest jargon of the anti-GW project.

But after a cycle of development, it could be paying for itself as an on-going project, employing thousands who are otherwise unemployed.

Win - win - win !

Cheers,

Joe