The Methane Hydrate Meltdown: A Natural Experiment from 55 million years ago

Imagine embarking on an extraordinary journey to the depths of the ocean, where you’ll uncover the secrets of methane hydrates, frozen treasures that hold immense power over our planet’s climate. Along this captivating exploration, you’ll discover how these ice-like formations trap vast stores of methane, a potent greenhouse gas, and how their thawing poses a significant threat to global warming. You’ll learn about the Paleocene-Eocene Thermal Maximum, a natural experiment that occurred 55 million years ago, when a massive release of methane from methane hydrates triggered a rapid warming event. This journey will not only enlighten you about the delicate balance of Earth’s climate system but also inspire you to become a steward of our planet, taking action to protect it from the consequences of methane emissions.

Firefly a chunk of methane hydrate that looks like a piece of ice, as it burns on fire in contact wi

Methane hydrates around the world

A chunk of methane hydrate looks like a piece of ice. But it’s really highly concentrated molecules of methane — the chief constituent of natural gas — trapped in a cage-like lattice of ice. As it melts, huge amounts of methane bubble out. These hydrates have been an isolated curiosity in the lab for a century. But in the past couple of decades, researchers have discovered vast methane hydrate deposits, sometimes several hundred meters — maybe a thousand feet — thick in arctic permafrost and in deep ocean sediments around most of the continents.

In methane hydrates, the methane is so concentrated that one unit in the hydrate structures can release 160 times its volume in gas. On the Blake Ridge of the North Carolina coast, a mile and a half below the surface, 300-square-mile area there holds enough methane to supply the United States with natural gas for 100 years.

Today, methane hydrates have been detected around most continental margins. Around the United States, large deposits have been identified and studied in Alaska, the west coast from California to Washington, the east coast, including the Blake Ridge offshore of the Carolinas, and in the Gulf of Mexico. Scientists have known about methane hydrates for a century or more.

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US Atlantic Margin Gas Hydrates | SpringerLink

French scientists studied hydrates in 1890. In the 1930s, as natural gas pipelines were extended into colder climates, engineers discovered that hydrates, rather than ice, would form in the lines, often plugging the flow of gas. These crystals, although unmistakably a combination of both water and natural gas, would often form at temperatures well above the freezing point of ordinary ice.

Natural gas in the frozen state

In 1964, in a northern Siberian gas field named Messoyakha, a Russian drilling crew discovered natural gas in the “frozen state,” or in other words, methane hydrates occurring naturally.

Methane hydrates tube

In late 1981, the drilling vessel Glomar Challenger, assigned by the National Science Foundation to explore off the coast of Guatemala, unexpectedly bored into a methane hydrate deposit. Unlike previous drilling operations which had encountered evidence of hydrates, researchers onboard the Challenger were able to recover a sample intact.

And that represents a lot of natural gas — some 80 thousand times the current natural gas reserves — with an energy potential of more than twice that of all other fossil fuels combined. But this immense resource is costly and dangerous to recover. There are drilling problems — especially from the seafloor where decomposing hydrates can cause underwater mudslides and even tidal waves.

And scientists are concerned that melting methane hydrates could contribute to global warming as the highly concentrated methane is released into the air. Next article … a scientist who says it’s already happened naturally — 55 million years ago.

The Peril of Melting Methane Hydrates

In the depths of the oceans, vast stores of methane lie trapped within ice-like formations called methane hydrates. These methane hydrates play a crucial role in regulating Earth’s climate, acting as a natural carbon sink. However, as the global temperature rises, these methane hydrates are beginning to thaw, releasing their trapped methane gas into the atmosphere.

FACTS:

  • The existence of methane hydrates in the ocean depths has been confirmed through direct sampling and geophysical surveys.
  • The observation of methane seeps from the ocean floor provides further evidence of the presence of methane hydrates and their potential for release into the atmosphere.
  • Studies have shown that methane hydrates are sensitive to changes in temperature and pressure, and that they are beginning to thaw as a result of global warming.

Methane’s Potent Greenhouse Effect

Methane, a potent greenhouse gas, traps heat from the sun much more effectively than carbon dioxide. This means that even small releases of methane can have a significant impact on global warming. Scientists estimate that the release of methane from melting methane hydrates could contribute up to 20% of the total warming expected by the end of the 21st century.

FACTS:

  • Methane is a well-established greenhouse gas with a global warming potential 25 times greater than that of carbon dioxide.
  • Numerous scientific studies have documented the significant impact of methane on climate change.
  • The Intergovernmental Panel on Climate Change (IPCC) has identified methane emissions as a major contributor to projected global warming.

A Natural Experiment: The Paleocene-Eocene Thermal Maximum

Approximately 55 million years ago, Earth experienced a rapid warming event known as the Paleocene-Eocene Thermal Maximum (PETM). This period of intense warming is thought to have been triggered by a massive release of methane from methane hydrates.

The Paleocene-Eocene Thermal Maximum (PETM), a period of rapid global warming approximately 55 million years ago, was triggered by a massive release of methane from methane hydrates. Scientists analyzed ancient sediment cores and fossil records to reconstruct the environmental conditions during the PETM. They discovered elevated levels of methane isotopes in the sediments, indicating a sudden increase in methane emissions during this period. The observed changes in vegetation and ocean conditions were consistent with the effects of methane-induced warming. These findings suggest that the release of methane from methane hydrates played a key role in driving the PETM warming event.

FACTS:

  • The Paleocene-Eocene Thermal Maximum (PETM) is a well-documented period of rapid global warming that occurred approximately 55 million years ago.
  • Evidence from geological records, including sediment cores and fossil records, indicates a significant increase in atmospheric methane during the PETM.
  • Studies have shown that the methane released during the PETM likely played a key role in driving the rapid warming event.

Evidence of Methane’s Role in the PETM

Scientists have found compelling evidence suggesting that methane played a significant role in the PETM. They have discovered elevated levels of methane isotopes in ancient sediments, indicating a sudden increase in methane emissions during this period. Additionally, they have found evidence of changes in vegetation and ocean conditions that are consistent with the effects of methane-induced warming.

Elevated levels of methane isotopes in ancient sediments provide direct evidence of a sudden increase in methane emissions during the PETM. Changes in vegetation and ocean conditions observed in the geological record are consistent with the effects of methane-induced warming.

Studies have shown that the observed changes in methane levels and climate conditions are best explained by a massive release of methane from methane hydrates.

Implications for the Future of the Methane Hydrate

The discovery of methane’s role in the PETM raises concerns about the potential consequences of melting methane hydrates in the present day. If a significant amount of methane is released from these hydrates, it could accelerate global warming and lead to unpredictable and potentially catastrophic climate change.

FACTS:

  • The findings from the PETM suggest that methane emissions from melting methane hydrates could significantly accelerate global warming in the present day.
  • The potential release of methane from thawing hydrates could lead to unpredictable and potentially catastrophic climate change.
  • The discovery of methane’s role in past warming events underscores the importance of mitigating human-caused methane emissions and preventing the thawing of methane hydrates.

A Warning from the Past

The Paleocene-Eocene Thermal Maximum serves as a stark reminder of the potential consequences of methane emissions. The findings from this natural experiment underscore the importance of mitigating human-caused methane emissions and preventing the thawing of methane hydrates. By understanding the past, we can better prepare for the future and take action to protect our planet’s climate.

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