Scientist predicts "mass extinction" due to carbon spike

The MIT scientist, Daniel Rothman, has published new findings suggesting that the Earth would be on the road to a "mass extinction" event if we exceeded the threshold of carbon dioxide in our oceans.

The current rate at which carbon dioxide enters the oceans, he says, could lead to an unstoppable cascade of chemical reactions. Rothman says we can be worrying "close to this critical threshold."

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Chemical feedback

Rothman, professor of geophysics and co-director of the Lorenz Center of the Department of Earth Sciences, Atmosphere and Planets at MIT, said the future could be very dark if we go beyond the carbon dioxide threshold in our oceans .

Exceeding the threshold could create a catastrophic feedback loop – the influx of carbon dioxide into the oceans causing extreme ocean acidification, which would result in an even greater release of carbon dioxide.

This "global reflex," says an MIT press release, would lead to enormous changes in the amount of carbon in the Earth's oceans, with potentially disastrous consequences.

Geological recordings

Using geological records, geologists such as Rothman compare evidence of changes to sediment layers that have been stored for hundreds of millions of years with current levels of CO2 in our oceans.

For his own research, Rothman has gone through these recordings and observed that over the past 540 million years, carbon stocks in the ocean have changed dramatically – often dramatically before coming back at their previous level.

This "excitement" of the carbon cycle is particularly present at the time of four of the five major mass extinctions in Earth's history.

In other words, models similar to the one we are currently observing have a correlation, in the history of the Earth, with catastrophic events.

Effects on our modern climate

Unlike previous peaks of carbon dioxide in the ocean, we are currently witnessing a much faster increase in levels due to human pollution.

According to the MIT press release, "Today's oceans absorb carbon about an order of magnitude faster than the worst case in the geological record – the Permian's final extinction."

In the past, it took tens of thousands of years or more before volcanic eruptions and other natural causes caused environmental problems. Humans, however, have been releasing carbon dioxide into the atmosphere only for hundreds of years – the rate at which it occurs is unprecedented.

Today, we are "on the brink of excitement," says Rothman in the MIT article.

If this happens, testimonies of past global extinction events suggest that we could be faced with a similar global catastrophe.

"Once the threshold is crossed, the way we got there is no longer important," says Rothman. All we know is that humans are rapidly increasing the amount of CO2 in our atmosphere. "Once you have overcome this problem, you must understand how the Earth works and make its own journey."

Rothman publishes his results this week in the Proceedings of the National Academy of Sciences.