Human Carbon Dioxide Emissions could match with PETM in the next 140 Years

Human Carbon Dioxide Emissions could match with PETM in the next 140 Years

Human Carbon Dioxide Emissions could match with PETM in the next 140 Years

According to a recent study, the carbon levels on Earth may reach the levels observed during the Paleocene-Eocene Thermal Maximum (PETM) in fewer than 5 generations.

PETM is a global warming event that took place around 56 million years ago and is the last major greenhouse event known to humanity. Researchers found that humans are pumping Carbon Dioxide into the atmosphere at a much faster rate (9-10 times) than what was done during the PETM. Consequently, it is being predicted that the total amount of emitted Carbon Dioxide (since the initiation of fossil fuel combustion) could match with the quantity of greenhouse gas emitted during the PETM in near future. Scientists estimate that it might happen as early as 2159. Philip Gingerich, the Author of the study who serves as a Paleoclimate Researcher at the University of Michigan, referred to that by saying,

“You and I won’t be here in 2159, but that’s only about four generations away. When you start to think about your children and your grandchildren, and your great-grandchildren, you’re about there.”

Significance of PETM

More often than not, PETM is used as a benchmark to compare climate change. The latest research showed that we might achieve this level much quicker than previous estimates because the rate of modern warming is faster than any climate event that has happened since the extinction of dinosaurs. Gabriel Bowen, a Geophysicist at the University of Utah who was not included in the study, acknowledged that the rates of carbon release that are happening today are really unprecedented, even in the context of an event like the PETM. We don’t have much in the way of geologic examples to draw from in understanding how the world responds to that kind of perturbation.

Comparison

Researchers are unclear about the source of the PETM but they are confident that the massive amount of Carbon Dioxide was released into the atmosphere of our planet during that period. This resulted in an increase of 5-8 degrees Celsius in the average global temperatures. As a result, the average temperatures rose up to 23o C, which is nearly 7o C above the current upper bound. Scientists believe that the Arctic was home to palm trees and crocodiles while both the poles were ice-free, during that time. Similarly, a rough estimate indicates that nearly 3,000-7,000 gigatons of Carbon Dioxide were released over a span of 3,000 to 20,000 years. The temperature spike caused a large-scale extinction of many deep ocean organisms that are a key link in the marine food web.

In order to compare the emissions of the PETM with the modern day Carbon emissions, Gingerich figured out a mathematical way, which showed that the rate of these emissions is 9 to 10 times higher in today’s world.  He projected this rate into the future and deduced that humanity could face another PETM-like scenario within the next 140 years. The results revealed that the lowest estimate of carbon accumulated during the PETM (3,000 gigatons) can be reached in 2159. He also mentioned that humans have roughly emitted 1,500 gigatons of Carbon as of 2016.
Larisa DeSantis, a Paleontologist at Vanderbilt University who wasn’t a part of the researching team, acknowledged the severity of the situation and said,

“The fact that we could reach warming equivalent to the PETM very quickly, within the next few hundred years, is terrifying. We live in a very different world today, with different groups of animals, with humans being the dominant species… but we know there are many negative consequences of dramatic warming on vast numbers of species, including our own.”

Consequences of PETM

Although scientists are not sure about the exact environmental consequences of these PETM-like carbon levels, the drastic increment in temperature will certainly wipe-out a lot of species from the face of this Earth. DeSantis mentioned that some of the adaptive species might survive the heat that will last for thousands of years. She explained that in the following words:

“It’s not just about 100 years from now; it’s going to take significant periods of time for that carbon dioxide to make its way back into the Earth’s crust. We’re really committing ourselves to many thousands of years of a warmer world if we don’t take action quickly.”

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