Carbon, the building block of life, plays a crucial role in maintaining the delicate balance of Earth’s climate system. However, much of the planet’s carbon resides deep within its layers, where it is trapped for millions or even billions of years. The release of this carbon, known as carbon degassing, is a process that occurs primarily through volcanic eruptions and other geological activities. Understanding how carbon is released from Earth’s deepest layers helps us gain insight into the planet’s geological dynamics and its role in shaping the atmosphere over geological timescales.

In this blog, we’ll explore how carbon is released from the Earth’s deepest layers, its pathways to the surface, and its impact on the atmosphere and climate.

1. The Carbon Cycle: A Brief Overview

Before diving into how carbon is released from the Earth’s deep layers, it’s important to understand the carbon cycle. The carbon cycle is a continuous process that moves carbon through various Earth systems, including the atmosphere, oceans, living organisms, and the Earth’s interior. Deep Earth carbon refers to the carbon stored in the mantle, a layer of the Earth that extends about 2,900 kilometers (1,800 miles) beneath the surface.

Carbon enters the deep Earth mainly through subduction zones, where tectonic plates converge. At these zones, carbon-rich materials like oceanic crust and sediment are forced into the mantle. Over millions of years, the carbon undergoes various geological processes before it is eventually released back to the surface.

2. Carbon Storage in Earth’s Mantle

The Earth’s mantle, located beneath the crust, is rich in minerals and compounds capable of trapping carbon. Much of this carbon is stored in the form of carbonates, such as calcium carbonate (CaCO₃). As tectonic plates move and subduct, carbon-bearing rocks and sediments are drawn deep into the mantle, where they can be subjected to extreme heat and pressure.

In the mantle, carbon exists in different forms:

• Carbonates: Carbon dioxide (CO₂) reacts with minerals in the mantle to form carbonates.

• Diamonds: Some carbon remains stable in the form of diamonds, forming deep within the Earth’s mantle.

• Melted Rock: Under extreme conditions, carbon is often released as gases when mantle rocks melt.

The deep Earth serves as a long-term storehouse for carbon, keeping it out of the atmosphere for extended periods. However, this carbon must eventually make its way back to the surface through a process called degassing.

3. How Carbon Reaches the Surface

The process of releasing carbon from the Earth’s mantle to the surface is known as degassing. This happens in a few different ways:

Volcanic Eruptions

One of the most direct pathways for carbon to escape the mantle is through volcanic eruptions. When tectonic plates shift or mantle material melts, the resulting volcanic activity brings molten rock and gases to the Earth’s surface. Among the gases released during eruptions, carbon dioxide (CO₂) is one of the most prominent. This is the most significant natural process through which carbon is released back into the atmosphere.

Volcanic eruptions are particularly important because they can release large quantities of carbon quickly. This carbon may come from the mantle itself or from the crust, where carbon has been stored for billions of years. Volcanic hotspots like those found in Hawaii or Iceland are examples of locations where carbon is frequently released from the Earth’s interior.

Mid-Ocean Ridges

Another pathway for carbon to reach the surface is through mid-ocean ridges, which are underwater mountain chains that stretch across the world’s oceans. These ridges mark the boundaries of tectonic plates, where magma rises from the mantle to form new crust. As magma ascends, it can bring carbon to the surface in the form of dissolved gases, including CO₂. While this release occurs mainly underwater, the carbon still eventually makes its way into the global carbon cycle.

Continental Volcanism and Rift Zones

In addition to mid-ocean ridges, continental volcanic activity and rift zones also play a role in degassing. In regions where continental plates are pulling apart or where volcanic hotspots exist, carbon can be released through volcanic vents and fissures. Over time, carbon accumulates and is gradually released through these tectonic movements.

4. The Role of Subduction Zones in Carbon Release

Subduction zones are key players in the Earth’s carbon cycle. In these regions, oceanic plates collide with continental plates, forcing carbon-rich sediments into the mantle. As the carbon-bearing rocks are pushed deeper into the Earth, they experience intense heat and pressure, causing chemical reactions that release carbon in various forms.

Some of the released carbon is trapped in mantle minerals, but a significant portion is eventually released as gases during volcanic eruptions. The carbon that is subducted and subsequently degassed is part of the long-term cycling of carbon through Earth’s systems. Subduction not only brings carbon deep into the mantle but also helps return it to the surface, where it influences the atmosphere.

5. Impact on Earth’s Atmosphere and Climate

The release of carbon from the Earth’s deepest layers plays a significant role in the planet’s atmosphere and climate. Carbon dioxide is a potent greenhouse gas, meaning that its presence in the atmosphere helps to trap heat and regulate Earth’s temperature. However, the ongoing release of carbon can also have a profound effect on climate patterns, especially over long geological timescales.

Historically, periods of increased volcanic activity have been linked to periods of global warming, as more CO₂ is released into the atmosphere. This carbon can remain in the atmosphere for thousands to millions of years, influencing the Earth’s climate systems.

While carbon degassing from the mantle is a natural and ongoing process, the increased release of carbon due to human activities, such as burning fossil fuels, has contributed to the rapid acceleration of climate change. Understanding the natural processes of carbon release from the Earth’s depths helps scientists study both the natural and anthropogenic factors that influence global climate.

6. Monitoring and Research: Understanding Deep Earth Carbon

Scientists continue to monitor and study deep Earth carbon degassing to better understand its role in the carbon cycle. Techniques such as gas isotope analysis, volcanic gas sampling, and seismic imaging allow researchers to track the movement of carbon from the mantle to the atmosphere.

By studying volcanic eruptions and geological formations, scientists can gain insight into how carbon has been cycling through the Earth over millions of years. This research not only helps us understand Earth’s natural processes but also aids in predicting future changes in the climate.

Conclusion

Carbon’s journey from the Earth’s deep layers to the surface is a fascinating and complex process. Through volcanic eruptions, mid-ocean ridges, and subduction zones, carbon is gradually released into the atmosphere, where it contributes to the Earth’s carbon cycle and impacts global climate. Understanding how carbon is released from the Earth’s deepest layers is crucial to our understanding of the planet’s geological dynamics and its evolving climate.

As we continue to explore and monitor these natural processes, we can gain a better understanding of how carbon is both stored and released, helping us better address the challenges posed by climate change.

Carbon plays a pivotal role in regulating Earth’s climate, and while most of the attention surrounding carbon emissions focuses on human activities, there are natural processes at work beneath our feet that also release carbon into the atmosphere. One of the most significant yet often overlooked processes is deep Earth carbon degassing. This geological process involves the release of carbon stored deep within Earth’s mantle into the atmosphere, a phenomenon that can have implications for climate change and global warming.

In this blog post, we’ll explore the science behind deep Earth carbon degassing, its potential impact on global warming, and how understanding this natural carbon cycle is critical in the context of ongoing climate change.

1. What is Deep Earth Carbon Degassing?

Deep Earth carbon degassing refers to the release of carbon dioxide (CO2) and other carbon compounds from the Earth’s interior into the atmosphere. This process occurs primarily through volcanic activity and tectonic plate movements. Carbon is stored in the mantle, the layer of Earth beneath the crust, where it’s trapped in minerals and rocks. Over millions of years, this carbon can escape to the surface through volcanic eruptions or via the process of subduction, where tectonic plates carrying carbon-rich materials descend into the mantle.

While carbon degassing is a natural and essential process that has been occurring for billions of years, the increasing levels of carbon dioxide in the atmosphere due to human activities—such as fossil fuel combustion—has intensified the focus on carbon sources and sinks. Understanding deep Earth carbon degassing helps us comprehend the larger carbon cycle, especially in the context of the Earth’s overall climate system.

2. How Does Deep Earth Carbon Reach the Surface?

Carbon stored in the Earth’s mantle reaches the surface mainly through two processes: volcanic eruptions and tectonic activity.

• Volcanic Eruptions: Volcanic eruptions are the most direct and visible way that carbon from the deep Earth reaches the atmosphere. As magma rises to the Earth’s surface during an eruption, it brings with it gases—including carbon dioxide—that were trapped within the mantle. Once these gases are released into the atmosphere, they contribute to the carbon budget.

• Tectonic Plate Movements: In addition to volcanic eruptions, the movement of tectonic plates plays a role in carbon degassing. As plates subduct into the mantle, carbon-rich materials such as sediment and oceanic crust are transported deep into the Earth’s interior. Some of this carbon is released back into the atmosphere through volcanic activity, but it can also be stored in the form of minerals in the mantle. The recycling of carbon through these plate movements is a slow, continuous process.

Over geological timescales, these natural processes maintain a balance in the Earth’s carbon cycle. However, the current rate of human-induced carbon emissions is overwhelming this natural balance.

3. The Role of Deep Earth Carbon in the Carbon Cycle

The carbon cycle is a fundamental process that regulates the amount of carbon in Earth’s atmosphere. While human activities have increased atmospheric CO2 levels significantly in recent decades, natural processes such as deep Earth carbon degassing have always been an integral part of this cycle.

Deep Earth carbon degassing operates alongside other carbon processes, such as photosynthesis and ocean absorption, to maintain equilibrium in the atmosphere. However, the amount of carbon released from the Earth’s mantle is relatively small compared to the levels being added by human activity, which is why the additional emissions from burning fossil fuels and deforestation have been so impactful on the climate.

Scientists have been able to estimate that volcanic activity contributes a small fraction of the total CO2 in the atmosphere—about 0.1 to 0.3 gigatons of carbon per year, compared to the 10 gigatons per year released by human activities. Although it’s a natural process, the volume of carbon released through degassing is not enough to offset the anthropogenic emissions that are driving current global warming trends.

4. Impact of Deep Earth Carbon on Global Warming

While deep Earth carbon degassing alone doesn’t contribute significantly to current global warming, it’s essential to understand its role within the broader context of the Earth’s natural carbon cycle. When combined with other carbon sources, the cumulative effect on the atmosphere can be substantial over long geological periods.

The release of CO2 from deep Earth processes can lead to slight, long-term changes in atmospheric carbon levels. However, the real concern lies in the rapid pace at which carbon is being added to the atmosphere through human activities. This excess CO2 traps heat in the atmosphere, contributing to the greenhouse effect, which is the primary driver of global warming.

Over geological timescales, deep Earth carbon degassing helps maintain a balance in the carbon cycle, but the speed at which carbon is currently being emitted by human activities is unprecedented. The accelerated rate of fossil fuel combustion, land-use changes, and deforestation far surpass the natural degassing processes, tipping the balance and causing rapid temperature increases in the short term.

5. What Can We Do About Deep Earth Carbon and Global Warming?

While we cannot control the natural processes of deep Earth carbon degassing, we can take action to mitigate the impact of human-induced carbon emissions. Here are some ways to reduce our carbon footprint:

• Reduce Fossil Fuel Emissions: The most significant contributor to global warming is the burning of fossil fuels for energy. Transitioning to renewable energy sources like wind, solar, and hydropower can dramatically reduce CO2 emissions.

• Reforestation and Afforestation: Forests act as carbon sinks, absorbing carbon dioxide from the atmosphere. Protecting existing forests and planting new ones is essential for managing the carbon cycle and combating climate change.

• Carbon Capture and Storage: Technologies that capture CO2 emissions from industrial sources and store them underground or use them for other purposes could help offset some of the emissions caused by human activity.

• Sustainable Agriculture: Changes in land use, such as shifting towards sustainable farming practices and reducing deforestation, can reduce the amount of CO2 released into the atmosphere.

6. The Bottom Line: Deep Earth Carbon and Climate Change

Deep Earth carbon degassing plays a role in the natural carbon cycle, but it’s the human-driven increase in carbon emissions that is the primary cause of current global warming. Understanding the processes behind deep Earth carbon release is essential for studying Earth’s long-term carbon cycle and climate dynamics. However, addressing the challenges of global warming requires concerted efforts to reduce human-made carbon emissions, protect natural carbon sinks, and explore innovative technologies for carbon management.

The Earth’s climate system is complex, influenced by numerous factors ranging from atmospheric composition to ocean currents and solar radiation. One factor that plays a significant role but often goes unnoticed is the process of deep Earth carbon degassing. This natural phenomenon, which involves the release of carbon from the Earth’s interior into the atmosphere, can have both short-term and long-term effects on global temperatures and climate patterns. In this blog, we’ll explore how deep Earth carbon degassing occurs and its potential impact on our climate.

What Is Deep Earth Carbon Degassing?

Deep Earth carbon degassing refers to the process by which carbon stored in the Earth’s mantle and crust is released into the atmosphere through volcanic activity, geological faults, and other tectonic processes. The majority of this carbon is in the form of carbon dioxide (CO2), a potent greenhouse gas that plays a key role in regulating Earth’s temperature.

This process is part of the natural carbon cycle, where carbon is stored in various Earth reservoirs, including the oceans, atmosphere, and deep Earth. Over geological time scales, carbon is gradually transferred between these reservoirs through processes such as volcanic eruptions, the subduction of tectonic plates, and the weathering of rocks.

The Role of Volcanic Activity in Carbon Degassing

Volcanic eruptions are the primary mechanism of deep Earth carbon degassing. When tectonic plates collide, one plate may be forced beneath another in a process called subduction. As the plate sinks into the mantle, carbon-rich materials such as carbonates are carried deep into the Earth. Under intense heat and pressure, these materials undergo chemical changes, releasing carbon dioxide as a byproduct. This carbon dioxide then escapes the Earth’s interior through volcanic eruptions, where it is released into the atmosphere.

Volcanic eruptions are not just dramatic events on the surface—they are crucial for understanding the larger carbon cycle. The amount of CO2 released from volcanoes has been shown to fluctuate depending on the level of tectonic activity and the size of eruptions. Major volcanic eruptions, like the eruption of Mount St. Helens in 1980, can release significant amounts of CO2, momentarily influencing global atmospheric conditions.

How Carbon Degassing Affects Global Climate

Carbon dioxide is one of the most powerful greenhouse gases, meaning it traps heat in the Earth’s atmosphere and contributes to the greenhouse effect. The release of large amounts of CO2 from deep Earth carbon degassing can, therefore, have a profound impact on Earth’s climate.

Over long periods, volcanic activity can lead to a gradual increase in atmospheric CO2 levels, contributing to global warming. This warming occurs because the additional CO2 traps more heat in the atmosphere, raising global temperatures. In extreme cases, prolonged volcanic activity, or a series of massive eruptions, could lead to significant climate shifts. For example, the end of the Permian period, which saw the most significant mass extinction event in Earth’s history, has been linked to widespread volcanic activity and the release of large amounts of CO2 into the atmosphere.

On the flip side, volcanic eruptions can also have temporary cooling effects. During a large eruption, such as the 1991 eruption of Mount Pinatubo in the Philippines, massive amounts of ash and sulfur dioxide (SO2) are released into the atmosphere. These particles can block sunlight and temporarily lower global temperatures, a phenomenon known as “volcanic winter.” However, this cooling effect is short-lived compared to the long-term warming impact of CO2 emissions from volcanic degassing.

The Long-Term Impact of Carbon Degassing on Earth’s Climate

While the immediate effects of volcanic eruptions and carbon degassing are often localized or short-term, the long-term impacts can be much more significant. Over millions of years, deep Earth carbon degassing has been one of the driving forces behind Earth’s long-term climate cycles, including ice ages and periods of warming.

The Earth’s carbon cycle is largely controlled by processes such as plate tectonics, volcanic activity, and the weathering of rocks. These natural processes regulate the amount of carbon dioxide in the atmosphere and help stabilize Earth’s temperature. However, when carbon degassing occurs at accelerated rates, it can tip the balance and lead to a warming climate.

For instance, studies of the Earth’s geological past have shown that periods of increased volcanic activity and carbon degassing have often been followed by global warming and the retreat of ice sheets. These warming periods coincide with increases in atmospheric CO2 levels, which trap more heat in the atmosphere.

The Connection Between Carbon Degassing and Climate Change

In recent times, human activities—primarily the burning of fossil fuels—have dramatically increased the amount of CO2 in the atmosphere, driving climate change at an unprecedented rate. While deep Earth carbon degassing has always been a part of Earth’s natural carbon cycle, the additional CO2 released by human activities has overwhelmed the Earth’s natural ability to balance atmospheric carbon levels.

However, understanding deep Earth carbon degassing helps scientists predict future climate changes and assess the long-term stability of our planet’s climate system. By studying the history of carbon degassing, scientists can better understand how carbon cycles through the Earth and its atmosphere, giving us valuable insights into the role of natural processes in climate change.

Conclusion: The Ongoing Dance Between Earth and Climate

Deep Earth carbon degassing plays a critical role in shaping our climate, both in the past and present. The process of carbon release from the Earth’s interior, primarily through volcanic activity, is a natural part of the Earth’s carbon cycle. While the immediate effects of carbon degassing may be temporary, the long-term impact can lead to significant climate shifts over millions of years.

In the context of current climate change, understanding how deep Earth carbon degassing interacts with human-induced carbon emissions is key to predicting future climate scenarios. By studying the natural processes that govern carbon movement through the Earth, scientists can better understand the delicate balance that sustains Earth’s climate and how human activities are altering this balance.

As we continue to monitor volcanic activity, tectonic movements, and atmospheric CO2 levels, one thing is clear: the Earth’s climate is a dynamic system shaped by both natural and human forces. The role of deep Earth carbon degassing in this system is complex, but it remains an important piece of the puzzle in understanding and mitigating the effects of climate change.

Carbon is one of the most important elements on Earth, playing a critical role in everything from the formation of life to the regulation of the planet’s climate. While much of our focus tends to be on carbon emissions from human activities, there is another significant source of carbon that originates deep within the Earth’s mantle: carbon degassing. This natural process has profound implications for the carbon cycle, the Earth’s climate, and our understanding of geological processes. In this blog, we’ll dive deep into what carbon degassing from the Earth’s mantle is, how it works, and its implications for the environment.

What is Carbon Degassing?

Carbon degassing refers to the process by which carbon, in the form of carbon dioxide (CO2), is released from the Earth’s interior to the atmosphere. This occurs primarily through volcanic activity, where gases trapped deep within the mantle and the crust are brought to the surface during volcanic eruptions. The carbon that is degassed from the mantle has been stored for millions to billions of years, and its release is an essential part of the Earth’s natural carbon cycle.

Carbon can exist in the Earth’s mantle in various forms, including as part of minerals like carbonates or as dissolved gas in molten rock. When the conditions are right—such as during volcanic eruptions—this carbon is released into the atmosphere, contributing to the global carbon budget. The amount of carbon degassed is significant, but it is just one component of the broader process that regulates the Earth’s carbon balance.

The Mechanism of Carbon Degassing from the Mantle

The Earth’s mantle is an enormous reservoir of carbon. The carbon in the mantle is primarily stored in minerals, but it can also exist as a gas dissolved in molten rock, particularly in volcanic regions where mantle material is brought closer to the surface. When magma ascends from the mantle toward the Earth’s crust, it carries carbon along with it.

At shallower depths, the pressure decreases, causing the dissolved gases, including carbon dioxide, to come out of solution. This results in the release of carbon gases into the atmosphere during volcanic eruptions or through more passive processes like volcanic degassing at fissures and cracks in the Earth’s surface. The rate of carbon release depends on the level of volcanic activity and the specific geological conditions of the region.

In addition to volcanic eruptions, tectonic activity also plays a role in the degassing process. As tectonic plates move, they can push carbon-rich materials from the surface into the mantle, where they are stored for long periods. Over millions of years, the carbon that is sequestered deep within the Earth can eventually be released through volcanic activity.

Carbon Degassing and the Earth’s Carbon Cycle

Carbon is constantly cycling through the Earth’s atmosphere, oceans, soil, and interior. This cycle, known as the carbon cycle, regulates the planet’s climate and supports life. Carbon degassing from the Earth’s mantle is one of the key processes in this cycle, as it releases carbon that has been stored deep underground.

The carbon released from the mantle primarily comes from two sources: carbonates in the Earth’s crust and the deeper mantle material. The release of carbon from the mantle via volcanic activity and degassing represents a natural mechanism for carbon to return to the atmosphere, where it can be absorbed by plants and oceans or contribute to the greenhouse effect.

In the long run, the Earth’s ability to sequester carbon in the mantle can act as a form of climate regulation. For example, carbon stored deep in the mantle can be released gradually over millions of years, preventing a sharp rise in atmospheric carbon. However, human activities—such as burning fossil fuels and deforestation—have increased atmospheric carbon levels much more rapidly than in the past, potentially disrupting the natural balance of the carbon cycle.

Implications of Carbon Degassing for Climate Change

Understanding carbon degassing is essential for assessing its implications for climate change. While the amount of carbon degassed from the mantle is relatively small compared to human-made carbon emissions, it still plays a crucial role in the Earth’s long-term carbon budget. Over geological timescales, the release of carbon from volcanic eruptions can have significant effects on the atmosphere and the climate.

The carbon released from the mantle contributes to the greenhouse effect, which traps heat in the Earth’s atmosphere and raises global temperatures. In pre-industrial times, natural carbon degassing was balanced by the Earth’s natural processes that stored carbon, such as the burial of organic matter in sediments. However, the dramatic increase in carbon emissions from human activity has disrupted this balance, leading to an accelerated warming of the planet.

While carbon degassing is a slow process compared to human carbon emissions, it can still influence climate patterns over time. For instance, periods of increased volcanic activity—such as during tectonic shifts or the formation of large volcanic arcs—could lead to an uptick in atmospheric carbon, potentially contributing to warming trends or shifts in weather patterns. However, the natural system of carbon sequestration within the Earth’s mantle also acts to slow down the process of long-term warming, making the Earth’s carbon cycle a complex system of feedback loops.

The Future of Carbon Degassing Research

Studying carbon degassing from the Earth’s mantle is critical for understanding how our planet manages carbon over geological timescales. Geologists are increasingly using advanced techniques to study volcanic gases, including carbon isotopes, to gain insight into the behavior of carbon deep beneath the Earth’s surface. These studies help scientists better understand how carbon is stored and released over time and the long-term effects of carbon on the Earth’s atmosphere and climate.

As climate change becomes an ever-more pressing global issue, understanding the natural sources of carbon—and how they interact with human-made carbon emissions—will be essential for formulating effective climate models and mitigation strategies.

Conclusion

Carbon degassing from the Earth’s mantle is a fundamental process that shapes the planet’s carbon cycle and climate system. Though its direct contribution to current climate change is small compared to human activities, understanding this natural mechanism is key to unlocking the secrets of Earth’s long-term carbon dynamics. As research continues into the processes of carbon release and storage, we will be better equipped to predict and manage the environmental challenges posed by carbon emissions. In the broader context of climate science, knowledge of carbon degassing serves as a reminder of the intricate and interconnected systems that govern our planet’s carbon balance.

Volcanoes are more than just fiery spectacles—they play an essential role in regulating the Earth’s carbon cycle and climate. While we often think of volcanic eruptions as dramatic events that disrupt local environments, they are also a crucial part of the planet’s natural system for controlling carbon levels. These mighty forces of nature act as carbon release valves, helping to regulate the carbon stored deep within the Earth’s interior and influencing global temperatures over long periods of time. In this post, we’ll explore how volcanoes contribute to Earth’s carbon balance, their impact on climate, and their critical role in stabilizing our planet’s atmosphere.

The Role of Volcanoes in the Carbon Cycle
The Earth’s carbon cycle is a complex system involving the movement of carbon between the atmosphere, oceans, land, and the Earth’s interior. Carbon is naturally stored deep within the Earth’s mantle, and through the process of volcanic outgassing, volcanoes release carbon dioxide (CO2) into the atmosphere. This release is part of the deep carbon cycle, which operates over millions of years to maintain a balance between carbon stored in the Earth’s interior and the carbon in the atmosphere.

When tectonic plates collide and subduct beneath one another, carbon-rich materials are transported deep into the mantle. There, they can be stored for long periods, sometimes for millions of years. When the Earth’s tectonic plates shift, volcanic eruptions bring some of that carbon back to the surface in the form of CO2, where it is released into the atmosphere.

Why Volcanoes Are Essential for Climate Regulation
Volcanoes play a critical role in regulating Earth’s climate by influencing the levels of CO2 in the atmosphere. Carbon dioxide is a greenhouse gas, meaning it traps heat in the Earth’s atmosphere and contributes to the planet’s overall temperature. Volcanic eruptions release CO2, which can temporarily raise atmospheric carbon levels. However, this process is part of a long-term balance. Over millions of years, the release of carbon through volcanic eruptions has helped regulate Earth’s temperature and climate stability.

While individual eruptions may cause short-term warming, they can also have cooling effects. Large eruptions can release particulate matter such as ash and sulfur dioxide, which can reflect sunlight and cool the planet for a period. These cooling effects are often temporary, lasting from months to a few years, but they demonstrate how volcanoes are a part of the Earth’s natural climate regulation system.

The Impact of Volcanic Activity on Atmospheric CO2
Volcanic activity has long been a primary mechanism for transferring carbon from the Earth’s interior to the atmosphere. Over geological timescales, the Earth’s volcanic activity contributes to a steady release of carbon dioxide. While volcanic eruptions may seem sporadic, the cumulative effect of volcanic activity over millions of years has had a significant impact on atmospheric CO2 levels.

Interestingly, the total amount of CO2 released by volcanic eruptions is relatively small when compared to human-caused emissions from burning fossil fuels. However, the long-term, cyclical nature of volcanic carbon release plays a stabilizing role in the carbon cycle. Without volcanic eruptions, the Earth would have a much harder time maintaining the balance of carbon needed for a stable climate.

Volcanoes and the Earth’s Natural Thermostat
Volcanoes serve as a type of natural thermostat for Earth’s climate. When carbon dioxide is released into the atmosphere by volcanic eruptions, it can contribute to the greenhouse effect, warming the planet. However, this is a slow process, and over time, the Earth’s natural systems, including the deep carbon cycle, help regulate the release of carbon, ensuring that global temperatures don’t rise too quickly.

The balance between carbon storage in the Earth’s interior and the carbon released by volcanoes has helped maintain relatively stable temperatures for most of Earth’s history. Large volcanic events can cause temporary fluctuations in the climate, but over long periods, the natural cycle ensures that Earth remains habitable.

Volcanoes and Human Influence on the Carbon Cycle
While volcanic activity is a natural process that has been occurring for millions of years, human activities are now dramatically altering the carbon cycle. The burning of fossil fuels, deforestation, and industrial activities have caused a sharp increase in atmospheric CO2, overwhelming the Earth’s natural systems, including volcanic outgassing.

In recent decades, the increase in atmospheric carbon due to human activity has led to rising global temperatures and climate change. While volcanoes continue to release carbon, the amount of CO2 released by human activities far exceeds what is emitted by volcanic eruptions. Understanding the role of volcanoes in the carbon cycle is essential for recognizing the natural processes that contribute to climate regulation and the impact of human-caused emissions.

How Scientists Study Volcanoes and Carbon Emissions
Scientists study volcanic emissions to understand how much carbon dioxide is being released into the atmosphere and how it affects global carbon levels. Researchers use various methods to measure volcanic gases, including direct sampling during eruptions, satellite imaging, and analysis of volcanic rock samples. By studying volcanic activity and its impact on atmospheric CO2, scientists can better understand the long-term effects of volcanic outgassing on Earth’s climate.

In addition to monitoring current volcanic emissions, scientists also examine historical volcanic data to learn about past climate changes. By studying past eruptions and the release of carbon, scientists can gain insights into how volcanic activity has influenced global temperatures and climate stability over geological timescales.

Conclusion: Volcanoes: Nature’s Carbon Release Valves
Volcanoes are a critical component of the Earth’s natural carbon cycle, acting as nature’s carbon release valves. By releasing carbon dioxide from the Earth’s interior, volcanoes help regulate atmospheric CO2 levels and influence Earth’s climate. While individual eruptions may have short-term effects on global temperatures, the long-term impact of volcanic activity has been essential for maintaining a stable climate. Understanding how volcanoes function within the carbon cycle can help us better appreciate their role in shaping Earth’s climate and why they remain vital to the stability of our planet.

Earth is a dynamic and ever-changing planet, shaped by a variety of natural processes. While many people are familiar with surface-level phenomena like the water cycle or weather patterns, there’s a much deeper, less visible system that plays a critical role in maintaining the planet’s carbon balance. Often referred to as Earth’s “hidden engine,” the deep carbon cycle is responsible for regulating long-term carbon storage, atmospheric CO2 levels, and, ultimately, the stability of Earth’s climate. In this post, we will explore how this crucial cycle operates beneath our feet and why it matters so much to the health of our planet.

The Key Processes of the Deep Carbon Cycle:

1. Carbon Subduction:
   Carbon from the surface is drawn into the Earth’s interior through subduction zones, where tectonic plates meet. One plate slides beneath another, carrying carbon-rich materials such as carbonates and organic matter deep into the mantle. These materials are stored in the mantle for millions of years before being released through volcanic eruptions.

2. Volcanic Outgassing:
   Volcanoes play a crucial role in the deep carbon cycle by acting as release valves for carbon stored deep within the Earth. When tectonic plates move and magma rises, carbon dioxide (CO2) trapped in the mantle is released into the atmosphere through volcanic eruptions. This release of CO2 is a natural mechanism that regulates atmospheric carbon levels over time.

3. Plate Tectonics and Carbon Movement:
   The movement of tectonic plates is central to the deep carbon cycle. When plates collide and one is forced into the mantle, carbon is carried deep within the Earth. Over time, this carbon can remain stored for millions of years before it is released back into the atmosphere through volcanic activity. This process of subduction and volcanic eruption maintains a balance between the Earth’s interior and surface carbon.

Why Is the Deep Carbon Cycle Important?
The deep carbon cycle is critical for maintaining the Earth’s climate and supporting life. By controlling the flow of carbon between the Earth’s surface and interior, this cycle helps regulate global temperatures, prevent climate extremes, and ensure the stability of atmospheric CO2 levels. Without the deep carbon cycle, carbon could accumulate in the atmosphere or be trapped in the Earth’s crust, leading to drastic shifts in climate.

The Role of Volcanic Activity in Climate Regulation:
Volcanic eruptions are one of the primary ways that carbon is transferred from the Earth’s interior to the surface. However, volcanic activity does more than just release carbon dioxide; it can also influence short-term climate patterns. Large volcanic eruptions eject particles into the atmosphere, which reflect sunlight and can cause temporary cooling effects. This cooling influence, combined with the long-term release of CO2, helps maintain climate stability on a global scale.

How the Deep Carbon Cycle Affects Earth’s Climate:
While the deep carbon cycle operates on a geological timescale, its impact on Earth’s climate is significant. The amount of carbon dioxide in the atmosphere directly affects global temperatures, and the deep carbon cycle plays a key role in maintaining this balance. When volcanic activity releases CO2 into the atmosphere, it can trigger periods of warming. Conversely, when volcanic activity decreases, atmospheric CO2 levels fall, leading to cooling periods. This process helps to stabilize the Earth’s climate over millions of years.

Human Influence on the Deep Carbon Cycle:
While the deep carbon cycle operates naturally over millions of years, human activities are altering the carbon balance on a much shorter timescale. The burning of fossil fuels, deforestation, and industrial activities are releasing vast amounts of CO2 into the atmosphere at an unprecedented rate, disrupting the Earth’s natural carbon cycle. This increase in atmospheric carbon is accelerating climate change and shifting the balance of carbon on Earth. Understanding the deep carbon cycle is essential for developing strategies to mitigate these impacts and restore equilibrium.

How Scientists Study the Deep Carbon Cycle:
Studying the deep carbon cycle is a complex and ongoing process. Scientists use a variety of tools to investigate how carbon moves through the Earth’s interior, including seismic imaging, volcanic gas measurements, and laboratory simulations of high-pressure conditions. By examining volcanic rocks, mineral formations, and gas emissions, researchers can learn more about how carbon is stored, transported, and released within the Earth. This research helps scientists predict how the deep carbon cycle might evolve in the future and how it could impact global climate patterns.

Conclusion:
The deep carbon cycle is truly Earth’s hidden engine, working behind the scenes to regulate carbon storage, atmospheric CO2 levels, and climate stability. This natural process is essential for maintaining the conditions necessary for life on Earth. As human activities continue to disrupt the carbon balance, understanding the deep carbon cycle becomes more important than ever. By studying this hidden engine, we can gain a deeper understanding of our planet’s systems and better prepare for the challenges of climate change.

Twenty-eight DCO members came together from 29 April  –  4 May, 2018 at the Carnegie Institution for Science in Washington, DC to calculate a new estimate of global carbon dioxide (CO2) degassing from large volcanic emitters, small volcanic sources and diffuse degassing from volcanic regions. The synthesis of massive amounts of data was successfully tackled through a hands-on approach. Science talks were interspersed with breakout sessions, followed by more of the same.  “It was the most productive workshop I have ever attended,” said Terry Plank, DCO Executive Committee member and Reservoirs and Fluxes Science Community member (Columbia University, USA), “and should serve as a model for others to come.”

The DECADE synthesis workshop group attendees came prepared with a wealth of available volcanic emissions data they used to create a new global estimate.  Their work was exhaustive, with some of the highlights provided below.

The attendees evaluated emissions from subaerial volcanoes with active gas plumes to produce an updated and improved estimate of global SO2 flux. This quantity was then combined with their best present knowledge of C/S ratios in the plumes of those volcanoes to derive a corresponding emission of volcanogenic carbon.

They accounted for different types of emitters, including passively degassing volcanoes, explosive eruptions, and effusive eruptions and distinguished between arc and non-arc volcanic sources. They compiled data covering 11 years from 2005 to 2015, and used information from long-term monitoring from space (mostly OMI satellite) and ground (mostly NOVAC network), as well as short-term campaign data and reports from the literature. The group also identified the need for further comparisons between satellite- and ground-based flux observations and the lack of C/S data, in particular for large eruptions.

To improve estimates from small volcanic sources, they assembled a new compilation of worldwide data from more than 40 volcanoes that emit small CO2 plumes and carefully selected appropriate volcanoes to include in the extrapolation.  The group then individually reviewed more than 750 volcanoes from across the globe that could potentially host small plumes and categorized their emissions as ‘magmatic’, ‘hydrothermal’, or ‘none’.  Said Tobias Fischer (University of New Mexico, USA), one of the initial workshop organizers, “When complete, this analysis will be the most rigorous and transparent estimate of global CO2 emissions from small volcanic sources yet determined.”

Attendees also delivered the first estimate of global carbon dioxide (CO2) degassing from diffuse degassing sources of volcanoes based on the published data reported in MaGa, a recent catalogue of diffuse gas emissions around the world, while also addressing uncertainties of the data.  Other attendees analyzed subduction data that were providing insights into volatile cycling on both regional and global scales, while others considered what could be learned from the rock record.

Overall, the results from this workshop will provide new and more rigorously constrained global deep carbon emission estimates, new insights into the fate of subducted carbon and new methods for estimating volcanic CO2 fluxes through time using petrologic parameters. The workshop also highlighted the need for continued multi-disciplinary efforts in the area of volcanic and tectonic degassing to advance understanding of the transfer of volatiles between Earth’s reservoirs.

A joint study between Carnegie and the Woods Hole Oceanographic Institution has determined that the average temperature of Earth’s mantle beneath ocean basins was about 110 degrees Fahrenheit (60 Celsius) higher than previously thought, due to water present in deep minerals. The results are published in Science.

Earth’s mantle, the layer just beneath the crust, was the source of most of the magma that erupts at volcanoes. Minerals that make up the mantle contain small amounts of water, not as a liquid, but as individual molecules in the mineral’s atomic structure.  Mid-ocean ridges, volcanic undersea mountain ranges, are formed when these mantle minerals exceed their melting point, become partially molten, and produce magma that ascends to the surface. As the magmas cool, they form basalt, the most-common rock on Earth and the basis of oceanic crust. In these oceanic ridges, basalt can be three to four miles thick.

Studying these undersea ranges can teach scientists about what was happening in the mantle, and about the Earth’s subsurface geochemistry.

One longstanding question has been a measurement of what’s called the mantle’s potential temperature. Potential temperature was a quantification of the average temperature of a dynamic system if every part of it were theoretically brought to the same pressure. Determining the potential temperature of a mantle system allows scientists better to understand flow pathways and conductivity beneath the Earth’s crust. The potential temperature of an area of the mantle can be more closely estimated by knowing the melting point of the mantle rocks that eventually erupt as magma and then cool to form the oceanic crust.

In damp conditions, the melting point of peridotite, which melts to form the bulk of mid-ocean ridge basalts, was dramatically lower than in dry conditions, regardless of pressure. This means that the depth at which the mantle rocks start to melt and well up to the surface will be different if the peridotite contains water, and beneath the oceanic crust, the upper mantle was thought to contain small amounts of water—between 50 and 200 parts per million in the minerals of mantle rock.

So lead author Emily Sarafian of Woods Hole, Carnegie’s Erik Hauri, and their team set out to use lab experiments in order to determine the melting point of peridotite under mantle-like pressures in the presence of known amounts of water.

“Small amounts of water have a big effect on melting temperature, and this was the first time experiments have ever been conducted to determine precisely how the mantle’s melting temperature depends on such small amounts of water,” Hauri said.

They found that the potential temperature of the mantle beneath the oceanic crust was hotter than had previously been estimated.

“These results may change our understanding of the mantle’s viscosity and how it influences some tectonic plate movements,” Sarafian added.

The study’s other co-authors are Glenn Gaetani and Adam Sarafian, also of Woods Hole.

This research was funded by the National Science Foundation and the Woods Hole Oceanographic Institution’s Deep Ocean Exploration Institute.

The atmosphere that allows our planet to sustain life formed from gases emitted by volcanoes early in Earth’s history. These volatile elements are constantly recycled back into the deep Earth at subduction zones, where tectonic plates sink into the mantle. During this process the sinking plate was subjected to increasing heat and pressure, and releases volatiles. These volatiles, once added to the mantle, induce melting and fuel volcanic explosions, completing the cycle. While this depiction of the earth’s giant recycling factory was well established conceptually, they do not know how efficient it is. They can estimate how much goes in, but have little idea what proportion was released back to the atmosphere, and what proportion remains trapped at depth. This question was crucial if they want to understand how our atmosphere formed and our planet became able to sustain life. In the present-day context, characterizing how much gas comes out of the giant recycling factory was also key to understanding volcanic effects on climate, volcanic emissions being significant – but poorly constrained – parameters in current climate models..

Their team of early career volcanologists was conducting expeditions to the South American Andes. Their objective was to provide the first accurate and large-scale estimate of the flux of volatile species (H2O, H2, CO2, CO, SO2, H2S, HCl, HF, and more) emitted by volcanoes of the Nazca subduction zone. The journey was taking us across half a continent, from the giant volcanoes of Ecuador through the altiplanoes of Peru and to the Southern tip of Chile, traveling on some of the Earth’s highest roads, and climbing some of the Earth’s tallest volcanoes.