Today, the world?s climate is going through a major global alteration. Yet the change in our era isn?t that unique, considering the vast variations throughout our planet?s countless epochs.

More than 55 million years ago, a rapid warming event similar from that of today?s occurred, affecting the ecosystem of the planet.

 

Marine life thrived during the era, and now, scientists have found tiny fossils of them that may offer a better understanding of how climate change directly affected Earth?s organisms.

Could we possibly be able to preview the effects of climate change through these microfossils?

 

Marine life, as all forms of life do, depends on oxygen.

While terrestrial creatures breathe straight through the air, life under the sea is slightly complex. Oxygen molecules dissolve into the water, and organisms use this as a source of breathable air.

 

Climate change, therefore, impacts life in complicated ways – when looking at climate change and marine ecosystems, we must consider a couple of dimensions regarding the possible changes.

 

To begin with, researchers believe that hypoxia, or the loss of dissolved oxygen in marine environments, is a growing concern.

 

 

Moreover, in the field of Water Science and Engineering, scientists have found that it is difficult to predict future deoxygenation caused by carbon emissions.

Without a clear understanding of the planet's geologic history, it is difficult to make accurate conclusions only based on recent data.

 

While there are still numerous facts in geology yet to be unraveled, there are fewer people who actually truly understand what has already been proven.

 

 

 On top of that, deoxygenation caused by carbon emissions creates oxygen minimum zones that are larger in size and thicker in length.

An oxygen minimum zone is the layer of water in an ocean where oxygen saturation is at its lowest.

Considering these issues, what are some clues that tell us about the effects of climate change? In order to collect data, scientists have started to work with iodate, a type of iodine that exists only in oxygenated waters.

 

Using the iodate, the scientists are analyzing the ratios of iodine to calcium in microfossils. The ratio enables them to estimate the levels of oxygen in ambient seawater, where microorganisms once flourished.

One type of microfossil being used is a skeleton called foraminiferas.

 

As a part of the group of protists, the specific fossil is useful in terms of determining the extent of oxygen minimum zones. Scientists set an oxygen proxy for foraminfera to accurately calculate the extent.

The next step is comparing.

With the given fossil data in a similar climacteric environment to modern Earth, scientists are comparing what they know with the oxygen levels. 55 million years ago, oxygen minimum zones were found to be much more dominant than today.

 

However, due to deoxygenation, warming, and acidification, marine environments were disturbed. The environment no longer proliferated. These major planetary problems eventually provoked a mass extinction of the seafloor.

 

 

picture - from http://www.futurity.org/