Privileged Planet: plants control carbon cycle (Introduction)

by David Turell , Sunday, January 24, 2021, 15:53 (1400 days ago) @ David Turell

Photosynthesis plays a huge role now and in our history:

http://cshl.nautil.us/article/657/how-to-bury-carbon-let-plants-do-the-dirty-work?mc_ci...

"Forty-nine million years ago, a small aquatic fern called Azolla wrested control of Earth’s climate. At the time, the landlocked Arctic Ocean developed a surface layer of freshwater, which allowed the ferns to grow unchecked in a wide-open environment. Billions of tons of plants died and sank to the bottom of the ocean, taking with them the carbon they had sucked from the air when they were alive.

"The consequences were extreme. Geologic evidence indicates that atmospheric carbon dioxide levels plummeted more than 80 percent over 800,000 years, sharply ratcheting down Earth’s thermostat. Prior to the inferred “Azolla Event,” most of the globe was lush and tropical. Afterward, the Arctic cooled by nearly 40 degrees Fahrenheit, the poles froze, and our planet entered a lurching cycle of ice ages that continue to this day.

"The Azolla Event was an environmental catastrophe for life in the Eocene epoch. Today, though, it is a source of inspiration—even optimism—in dealing with human-driven climate change. For years, some researchers have promoted the idea of geoengineering, using technology to offset the effects of carbon emissions. Such schemes are commonly dismissed as pie in the sky, but the Azolla Event suggests otherwise. After all, if a bunch of dumb ferns could naturally perform carbon sequestration on such a tremendous scale, why couldn’t clever humans deliberately do the same thing?

“'It’s clear that plants have been able to contribute to really big geological events in the Earth's history,” says Rob Martienssen, a plant geneticist at Cold Spring Harbor Laboratory in Long Island. “Being able to harness that power and speed it up seems like a realistic goal to me.'”

Comment: The article goes on to discuss humans using plants to control CO2 on Earth and maintain balances within tight limits. It has been designed to run by itself until humans arrived to upset the balances. But it should be noted the range of CO2 concentrations, both high and low are way beyond anything currently happening.