Crabs have been around more than 100 Million years when CO2 levels were more than 3 times higher than today. At the same time, there was more carbonate deposition in the Cretaceous than anytime in earth’s history since the end of the Devonian. The only time CO2 levels have been as low as they are now was at the time of (very probably one of the causes of) the great extinction event at the end of the Devonian. The Devonian, by the way was the greatest period of carbonate deposition at >4000 PPM. All that carbonate deposition sucked down most of the carbon in the ocean and the air. The massive reefs suddenly died across the planet as CO2 was reduced below 180 PPM. It took 100 million years for CO2 and biodiversity to recover. Life sequesters CO2. Tectonic forces restore it. The last Ice advance brought CO2 levels to below 180 PPM, dangerously close to the end of photosynthesis. More carbon in the oceans for critters that live in calcium carbonate, historically, has been pretty good for life. Maybe it will be different this time.
Crabs have been around more than 100 Million years when CO2 levels were more than 3 times higher than today. At the same time, there was more carbonate deposition in the Cretaceous than anytime in earth’s history since the end of the Devonian. The only time CO2 levels have been as low as they are now was at the time of (very probably one of the causes of) the great extinction event at the end of the Devonian. The Devonian, by the way was the greatest period of carbonate deposition at >4000 PPM. All that carbonate deposition sucked down most of the carbon in the ocean and the air. The massive reefs suddenly died across the planet as CO2 was reduced below 180 PPM. It took 100 million years for CO2 and biodiversity to recover. Life sequesters CO2. Tectonic forces restore it. The last Ice advance brought CO2 levels to below 180 PPM, dangerously close to the end of photosynthesis. More carbon in the oceans for critters that live in calcium carbonate, historically, has been pretty good for life. Maybe it will be different this time.