Breaching ocean carbon threshold to greatly accelerate mass extinction

As the levels of CO2/carbon in the ocean increase, a runaway cascade of feedbacks may push this blue planet over its tipping point

The primary cause of the rise of CO2 in the oceans is indirectly due to CO2 levels in the atmosphere.

More importantly, it is due to the collapse of the oceans living photosynthetic system which would otherwise keep our planet ecosystem in balance

In a new paper in PNAS a theoretical climate mathematician from MIT has stated bluntly that by 2100 the ocean carbon of this blue planet is likely to be over a ‘tipping point.’ Many times in geologic history similar tipping points have been accompanied by global mass extinction events. The report notes that in the past 540 million years, the Earth has endured five mass extinction events, each involving processes that upended the normal cycling of carbon through the atmosphere and oceans. These globally fatal perturbations were coincident with the widespread mass extinctions of marine species around the world.

In the case of another mass extinction, the cyanobacteria as seen at the top of this post will survive.  Perhaps next time they will be a bit more selective as to whom they assist to evolve to cohabit their blue planet after the ‘blue screen of death event.’

Without attribution to the late great John Martin, my favourite oceanographer, who 30 years ago reported on the same crisis of rising ocean carbon levels being associated with ice ages and mass extinctions, Daniel Rothman, professor of geophysics and co-director of the Lorenz Center in MIT’s Department of Earth, Atmospheric and Planetary Sciences has now reiterated John Martin’s warning. He reports that he has confirmed that when the level at which carbon dioxide resides in the oceans pushes past a certain threshold—whether as the result of a sudden burst or a slow, steady influx—this Blue Planet has responded with a runaway cascade of feedbacks cataclysms.

Sedimentary rocks at Meishan, China contain signatures of a disturbance in the ocean carbon cycle immediately preceding Earth’s greatest mass extinction. Credit: Shuzhong Shen

This global ocean carbon reflex causes huge changes in the amount of carbon contained in the Earth’s oceans. Geologists can see evidence of these changes in layers of sediments preserved over hundreds of millions of years.

Over and over again

Rothman looked through these geologic records and observed carbon events over the last 540 million years. What he saw was that the ocean’s store of carbon changed abruptly, then recovered, dozens of times. This “excitation” of the carbon cycle occurred most dramatically near the time of four of the five great mass extinctions in Earth’s history.

Some scientists have tried to make light of the seriousness of this long-standing observation. Many suggesting that there may have been various unspecified triggers to these events and that the changes in ocean carbon that followed were proportional to the initial trigger. The smaller the trigger, the smaller the environmental catastrophe they suggest.

According to Rothman, that ‘don’t worry, be happy platitude‘ is clearly not the case. He found it didn’t matter what initially caused the ocean carbon enrichment events. For roughly half the disruptions in his database, once they were set in motion, the rate at which carbon increased as seen in the sedimentary record and the mathematical model was essentially the same. This rate change characteristic is likely a property of the ocean carbon cycle itself—not the external triggers.

Editors note: This makes perfect sense in a system regulated by a living ecology, but less sense and giving room for endless academic debate in a purely reductionist geochemistry test tube.

During the Permian Age, 250 million years ago, a gigantic volcanic magma flood, the Siberian event, took place if filled the atmosphere and oceans with CO2. The eruptions took 2 million years to push life in the oceans and the world into mass extinction.

Are We There Yet

Today’s oceans are accumulating carbon about an order of magnitude faster than the worst case in the geologic record—the Permian extinction. We humans have been pumping extraordinary amounts of carbon dioxide into the atmosphere for a hundred years or so. The earth has seen more CO2 going into the air in ancient times but in such cases, it took millions of years, not a mere hundred years. How might it be that modern brief increase of carbon might result in a major disruption?

According to Rothman, today we are

“At the precipice,”

“Once we’re over the threshold, how we got there may not matter,

“Once you get over it, you’re dealing with how the Earth works, and it goes on its own ride.”

In 2017, Rothman made an early dire prediction based on his mathematics: By the end of this century, the planet is likely to reach a critical threshold, based on the rapid rate at which humans are adding carbon dioxide to the atmosphere. When we cross that threshold, we are likely to set in motion a freight train of consequences, potentially culminating in the Earth’s sixth mass extinction.

Now with reports of the past 9 years…. click to read more if you dare

He has continued work on his model to better understand this prediction and the way in which the ocean carbon cycle responds once it’s pushed past a critical threshold.

The accumulation of carbon in the ocean is caused by two factors. One is the obvious increase of CO2 in the atmosphere, the central dogma of the world of climate change. The more potent ocean carbon driving force, however, is the decline of ocean phyto-synthesis, Nature’s only means to neutralize dangerously rising CO2. Without photosynthesis working at its maximum efficiency high CO2 in the air leads to its formation of carbonic acid as it combines with H2O.

The two vital ocean carbon equations are thus:

H2O + CO2 → H2CO3 (Carbonic Acid) and ocean death

H2O + CO2 + Plankton blooms/photosynthesis → New ocean life

Which would you prefer?

Chemistry vs. Ecology

While the MIT researcher seems to have understood the simple/complex geo-chemistry of oceans and CO2 he would receive an unsatisfactory mark in basic ocean ecology. The oceans are not a lifeless chemistry test tube where the simplest equations describe what goes on. The oceans are the most complex living system in the universe with tens of millions of unique and interacting species of life carrying on their jobs to keep their blue world livable. All of ocean life depends on the ‘bottom of the food chain’ the phytoplankton that use sunlight, CO2, and trace elements to make more of themselves. We know this plankton best from their beautiful plankton blooms.

Oceans are key to the carbon cycle. They’ve absorbed between a third and half of the CO2 that humans have emitted since the beginning of the Industrial Revolution, and the process lags atmospheric CO2 increases. More CO2 will end up in the oceans. One challenge is that CO2 binds with water in the ocean to make carbonic acid. That leads to weaker shells, and species-level threats for key components of the food chain, in addition to the direct impacts of the increased acidity.

That is a very big problem of a very different nature than global warming, aka climate change, but with the same root cause. We have to stop emitting CO2 so that oceans don’t acidify even more than absolutely necessary. But even if we stopped now, oceans would be getting more acidic for the next century or two, based on the trillion tonnes of yesterday’s CO2 that is already a lethal overdose for life as we like it.

The antidote is solar-powered ECORESTORATION not Geoengineering

Click to read more

The big impact of our high and rising CO2 is that our CO2 has been feeding the grasses of this planet’s landscapes. Grass you might recall is that short green vegetation that covers the dirt. When it is green and lush we call it good ground cover. When it has dried up and turned brown and the wind blows, the dust blows from the land. Today’s high CO2 is greening the planet and in doing so a greatly reduced amount of dust is blowing in the wind.

CO2 greens the land because grasses lose water when they breathe to take in CO2 from the air. In today’s 44% higher CO2 content in the air than 100 years ago the grasses of the world take fewer drying breaths of air and thus conserve their water. This is seen and reported widely in the scientific literature under the key terms ‘plant evapotranspiration‘.

More Grass Growing Means Less Dust Blowing

Less dust blowing in the wind is producing the greatest drought, a drought of vital dust, this planet’s green plants, ocean plants, have ever seen. But this time the green plants we speak of are the plankton that grow in the 72% of this blue planet that make up our ocean pastures. This is where 90% of all photosynthesis on this planet takes place, and it is only via free solar-powered photosynthesis that our deadly CO2, the trillion tonnes of yesterday’s CO2 that is killing our blue planet is made into life instead of death.

The MIT mathematician still has done a great service to the world of science by equating this ocean CO2/carbon feedback in his new model.  His differential equations describe interactions between the various chemical constituents in the upper ocean. He has then tested his equations on how the model responded as he mathematically pumped additional carbon dioxide into the system, at different rates and amounts.

Click to enlarge

He found that no matter the rate at which he added carbon dioxide to an already stable system, the carbon cycle in the upper ocean remained the same. In response to modest perturbations, the ocean carbon cycle would go temporarily out of whack and experience a brief period of mild ocean acidification, but it would always return to its original state rather than oscillating into a new equilibrium.

When he introduced carbon dioxide at greater rates, he found that once the levels crossed a critical threshold, the ocean carbon cycle reacted with a cascade of positive feedbacks that magnified the original trigger, causing the entire system to spike, in the form of severe ocean acidification. The system did, eventually, return to equilibrium, after tens of thousands of years in today’s oceans—an indication that, despite a violent reaction, the carbon cycle will resume its steady state.

This pattern matches the geological record, Rothman found. The characteristic rate exhibited by half his database results from excitations above, but near, the threshold. Environmental disruptions associated with mass extinction are outliers—they represent excitations well beyond the threshold. At least three of those cases may be related to sustained massive volcanism.

“When you go past a threshold, you get a free kick from the system responding by itself,” Rothman explains. “The system is on an inexorable rise. This is what excitability is, and how a neuron works too.”

We are today in a carbon age equivalent to the worst volcanic epochs in Earth’s history.

In the model that ignores the most powerful influence of ocean photosynthesis as a deadly carbon overdose antidote, things are already worse than we might imagine. Carbon is accumulating in the oceans today at an unprecedented rate. It is doing so over an unimaginable geologically brief time, a hundred years not a hundred millennia. Insofar as the tipping point is concerned, according to Rothman’s math, the modern world is in roughly the same place it was during longer periods of massive volcanism.

As today’s human-induced emissions continue to accumulate far beyond the threshold, Rothman predicts the consequences may be just as severe as what the Earth experienced during its previous mass extinctions.

“It’s difficult to know how things will end up given what’s happening today,” Rothman says. “But we’re probably close to a critical threshold. Any spike would reach its maximum after about 10,000 years. Hopefully that would give us time to find a solution.”

What this doomsday mathematics does not speak to is the immediate solution that is at hand.

We can be like a volcano that brings life to our blue planet, instead of like volcanoes that bring death. Here’s how.

Looking astern off the transom of my research ship before we began our dusting to restore the ocean to health the ocean was a blue desert. After dusting the same view revealed a beautiful emerald-green see that had become full of life. (No Photoshop, raw camera) – click to read more

It just works

In our distant patch of North Pacific, we weathered vicious 80+ mph winds, hurricane force, with waves blasting over the top of our 130 ft fishing/research ship.

Noone escaped seasickness, some worse than others as our cook was so ill we had to evacuate her to hospital. But we persevered and over the course of weeks hefted/man-handled 4000 50 lb bags of life-giving mineral deck from the holds of the ship to be diluted on deck and released to give dust back to the ocean to replenish and restore all of ocean life, from the bottom up.

Where before we began our dusty work in our intensive scientific surveys of that dying ocean pasture we rarely saw much of ocean life. A few birds each day was all. Once every few days perhaps one sighting of a whale. After the ocean came alive with incredible life.

You can read everywhere on this blog the facts that lead one to HOPE instead of fear. Join Me.