A
Anthony William Sloman
Guest
On Sunday, April 16, 2023 at 12:45:02â¯PM UTC+10, John Larkin wrote:
<snip>
500 million years ago the sun was appreciably smaller, and we got less solar radiation. We needed a thick blanket of CO2 to keep the planet warm.
So what.
the more recent peak about 55 million year ago
https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum
The biological effects weren\'t benefical - there were mass extinctions in the oceans, and massive dwarfing on land.
> Last few million years, so much CO2 was sequestered that plants were about to starve to death.
Total nonsense. Plants do fine during ice ages when the CO2 level drops to 180ppm
> Good thing we\'re fixing that. 1000 PPM would be nice.
You wouldn\'t like it if you got it, but you\'d probably starve to death long before CO2 levels got there. The agriculture that feeds you is optimised for the interglacial climate that prevailed when we were developing agriculture. We might be able to develop a new one with new crops growing in new areas, but there would be a population crash before we\'d finally got it right, and pollyannas like you wouldn\'t adapt as fast as they\'d need to.
--
Bill Sloman, Sydney
On Sat, 15 Apr 2023 20:40:52 -0400, Ed P <e...@snet.xxx> wrote:
On 4/15/2023 8:13 PM, T wrote:
On 4/15/23 06:51, Commander Kinsey wrote:
<snip>
The current global average concentration of CO2 in the atmosphere is 421
ppm as of May 2022. This is an increase of 50% since the start of the
Industrial Revolution, up from 280 ppm during the 10,000 years prior to
the mid-18th century. The increase is due to human activity.
CO2 was about 1600 PPM 50 million years ago, and around 5000 PPM 500 million years ago. The great explosions of plant and animal life happened at high CO2 levels; no coincidence.
500 million years ago the sun was appreciably smaller, and we got less solar radiation. We needed a thick blanket of CO2 to keep the planet warm.
During the Cambrian explosion it was around 4000.
So what.
the more recent peak about 55 million year ago
https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum
The biological effects weren\'t benefical - there were mass extinctions in the oceans, and massive dwarfing on land.
> Last few million years, so much CO2 was sequestered that plants were about to starve to death.
Total nonsense. Plants do fine during ice ages when the CO2 level drops to 180ppm
> Good thing we\'re fixing that. 1000 PPM would be nice.
You wouldn\'t like it if you got it, but you\'d probably starve to death long before CO2 levels got there. The agriculture that feeds you is optimised for the interglacial climate that prevailed when we were developing agriculture. We might be able to develop a new one with new crops growing in new areas, but there would be a population crash before we\'d finally got it right, and pollyannas like you wouldn\'t adapt as fast as they\'d need to.
--
Bill Sloman, Sydney