Climate Change May Reduce Organic Carbon Burial While Increasing Carbon Recovered to the Atmosphere

A worldwide team of scientists meticulously collected data from more than 50 years of seagoing scientific drilling operations to undertake a first-of-its-kind analysis of organic carbon that sinks to the ocean floor and is sucked deep into the globe.

Climate Warming Reduces Organic Carbon Burial Beneath Oceans

(Photo : Sarah Lee/Unsplash)

Because greater water temperatures enhance the metabolic rates of bacteria, their findings, published this week in Nature, shows that climate change might diminish organic carbon burial and increase the amount of carbon returned to the atmosphere.

Researchers from Rice University, Texas A&M University, the University of Leeds, and the University of Bremen examined data from drilled cores of muddy seafloor sediments collected during 81 of the International Ocean Discovery Program's (IODP) and predecessors' more than 1,500 shipboard expeditions.

Their research gives the most complete accounting of organic carbon burial during the last 30 million years, implying that scientists still have a lot to learn about the dynamics of the Earth's long-term carbon cycle.

"What we're discovering is that organic carbon burial is quite active," said Rice research co-author Mark Torres, as per ScienceDaily.

It varies dramatically, and it responds to the Earth's climatic system far more than scientists previously believed.

According to Texas A&M oceanographer Yige Zhang, if the new records are correct, they will modify a lot of our knowledge of the organic carbon cycle.

As the water warms, organic carbon will find it more difficult to find its way into the marine sediment system.

For decades, scientists have utilized isotopic ratios to determine the proportional quantities of inorganic and organic carbon buried at various stages in Earth's history.

According to Torres, experts assumed the quantity of carbon buried had changed relatively little over the previous 30 million years based on those research and computational calculations.

"We had this concept of taking real data and calculating their organic carbon burial rates to come up with the global carbon burial," Zhang explained, "and we wanted to check if this 'bottom-up' way coincided with the standard method of isotopic computations, which is more 'top down."

This was especially true during the mid-Miocene epoch, some 15 million years ago, according to Zhang.

The organic-rich "Monterey Formation" in California, for example, was thought to have buried a considerable quantity of organic carbon around this time.

According to the team's results, the least quantity of organic carbon was buried during this time throughout the previous 23 million years or so.

He highlighted the team's research as the start of a potentially transformative new method of data analysis that may assist in understanding and tackling climate change.

Storing Carbon Dioxide under the Ocean

One method of combating global climate change is to directly absorb and store carbon dioxide, the principal greenhouse gas, as it is emitted, as per MIT.

However, techniques of carbon dioxide sequestration, such as injecting the gas into subsurface geologic formations such as depleted oil reserves, are impractical in many regions and raise concerns that the stored carbon dioxide will leak.

Researchers at Harvard University and Columbia University have developed a novel method for capturing practically endless amounts of carbon dioxide, which they claim would be safe and practicable in regions distant from subterranean reservoirs.

The researchers realized that injections into the sea floor may make use of the ocean's pressure and warmth while avoiding the unfavorable side effects of previous ideas.

The liquid carbon dioxide would be transported to the sequestration location by ship or pipeline and pumped into the sea bottom using technology similar to that used by the oil sector to drill deep-sea wells.

Once beneath the sea bottom, the carbon dioxide would combine with the surrounding fluids, forming hydrate ice crystals that would cover the rock pores, acting as a secondary carbon dioxide cap.

The carbon dioxide would dissolve in the surrounding water over hundreds of years, leaving only the possibility of seeping out by diffusion, a sluggish process that would take millions of years, according to the researchers. They intend to conduct a large-scale field test of this novel technique within the next five years.

As concerns about the impact of carbon dioxide emissions on global climate change grow, scientists are looking for ways to clear the atmosphere of the greenhouse gas. However, industrial-scale efforts have been restricted thus far.

BP and GE, for example, recently launched a project in Scotland and California to create power facilities that produce hydrogen from fossil fuels and absorb the carbon dioxide byproduct.