Volcanoes Vs Cars: Who's The Bigger Polluter?

While volcanic eruptions release CO2 and other gases into the atmosphere, human activities, such as burning fossil fuels and deforestation, emit far more carbon dioxide than volcanoes. The impact of human activities on the carbon cycle exceeds that of all the world's volcanoes combined by more than 60 to 100 times. However, it is important to note that volcanic gases like sulfur dioxide can cause global cooling, while carbon dioxide released by volcanoes has the potential to contribute to global warming.

Human activity emits 60+ times more carbon dioxide than volcanoes annually

Human activity emits 60 or more times the amount of carbon dioxide released by volcanoes annually. While volcanic eruptions do contribute to an increase in atmospheric carbon dioxide, human activities, such as burning fossil fuels and deforestation, have a significantly larger impact.

Volcanoes emit carbon dioxide in two ways: during eruptions and through underground magma. Carbon dioxide from underground magma is released through vents, porous rocks, soils, and water that feeds volcanic lakes and hot springs. While large volcanic eruptions can release significant amounts of carbon dioxide, these events are rare and fleeting. In comparison, human activities emit billions of metric tons of carbon dioxide each year, with certain individual US states emitting more carbon dioxide annually than all the volcanoes on Earth combined.

The impact of human activities on the carbon cycle far exceeds that of volcanic eruptions. For example, human activities release an amount of carbon dioxide equivalent to a Mount St. Helens-sized eruption every 2.5 hours and a Mount Pinatubo-sized eruption twice daily. Furthermore, while volcanic gases like sulfur dioxide can cause global cooling, carbon dioxide released by volcanoes has the potential to promote global warming. However, the carbon dioxide released by contemporary volcanic eruptions has never caused detectable global warming.

Although volcanic activity has contributed to global warming and mass extinctions in the deep geologic past, current volcanic activity does not occur on the same massive scale. Today, human activities, such as burning fossil fuels for energy, are primarily responsible for the increase in atmospheric carbon dioxide and the resulting global warming.

In summary, while volcanoes can have a significant impact on the climate and the atmosphere, human activities emit far more carbon dioxide annually. The cumulative effect of human activities, such as burning fossil fuels and deforestation, greatly surpasses the carbon dioxide emissions from volcanic eruptions.

Volcanic gases can cause global cooling

While human activities emit 60 or more times the amount of carbon dioxide released by volcanoes annually, volcanic eruptions can still have a significant impact on the climate. Volcanic gases, such as sulfur dioxide, have been known to cause global cooling, while carbon dioxide released by volcanoes can contribute to global warming.

Volcanoes release gases, aerosol droplets, and ash into the stratosphere during major eruptions. The ash particles from volcanic eruptions can cause temporary cooling by blocking sunlight. However, the effect of ash on global cooling is less significant than that of sulfur dioxide. The sulfur dioxide released by volcanoes moves into the stratosphere, where it combines with water vapour to form sulfuric acid aerosols. These aerosols create a haze of tiny droplets that reflect incoming solar radiation back into space, leading to a cooling effect on the Earth's lower atmosphere or troposphere.

The conversion of sulfur dioxide into sulfuric acid occurs rapidly, and the resulting fine sulfate aerosols can remain in the stratosphere for up to three years. During this time, they can be carried by winds, causing significant global cooling. Several eruptions in the past century, such as the 1991 eruption of Mount Pinatubo, have resulted in a decline in average temperatures at the Earth's surface of up to half a degree Fahrenheit for one to three years.

The impact of volcanic eruptions on global cooling is influenced by the magnitude and frequency of the eruptions. While large volcanic eruptions can inject substantial amounts of carbon dioxide into the atmosphere, they are relatively rare. In comparison, human activities, such as burning fossil fuels, emit significantly more carbon dioxide annually than all the volcanoes on the planet combined.

In summary, volcanic gases, particularly sulfur dioxide, can lead to global cooling through the formation of sulfuric acid aerosols that reflect solar radiation. While volcanoes contribute to climate change, human activities have a far more significant impact on carbon dioxide emissions and, consequently, on global warming.

Volcanic carbon dioxide has the potential to cause global warming

While human activities such as burning fossil fuels, cement production, deforestation, and landscape changes emit far more carbon dioxide than volcanoes, volcanic carbon dioxide is a greenhouse gas with the potential to cause global warming.

Volcanoes emit carbon dioxide in two ways: during eruptions and through underground magma. While large volcanic eruptions can inject significant amounts of carbon dioxide into the atmosphere, they are too rare and fleeting to rival humanity's annual emissions. For instance, the 1980 eruption of Mount St. Helens released approximately 10 million tons of CO2 into the atmosphere in just 9 hours. In comparison, it currently takes humanity only 2.5 hours to emit the same amount. Furthermore, human activities released about 35 billion metric tons of CO2 in 2010, while volcanoes produce less than 1 billion metric tons annually.

Over the course of geologic time, volcanoes have occasionally contributed to global warming by producing significant amounts of carbon dioxide and other greenhouse gases. For example, geologists hypothesize that 250 million years ago, a massive flood of lava in Siberia may have raised global temperatures enough to cause one of the worst extinction events in Earth's history. However, current volcanic activity does not occur on the same massive scale, and volcanic eruptions often have the opposite effect of global cooling due to the release of other gases such as sulfur dioxide.

While the carbon dioxide released by contemporary volcanic eruptions has not caused detectable global warming, it is important to recognize that volcanic carbon dioxide has the potential to promote global warming. The impact of volcanic eruptions on climate change is a complex topic that requires further scientific investigation and our understanding of it may evolve over time.

Volcanic activity may be contributing to melting ice caps in Antarctica

While human activities emit 60 or more times the amount of carbon dioxide released by volcanoes annually, volcanic activity can still contribute to global warming by producing significant amounts of carbon dioxide and other greenhouse gases. In fact, some geologists hypothesize that 250 million years ago, a large-scale, long-lasting eruption raised global temperatures enough to cause one of the worst extinction events in history.

Volcanic gases like sulfur dioxide can cause global cooling, while volcanic carbon dioxide has the potential to promote global warming. The conversion of sulfur dioxide to sulfuric acid, which then forms fine sulfate aerosols, is the most significant climate impact from volcanic injections into the stratosphere. These aerosols increase the reflection of radiation from the Sun back into space, cooling the Earth's lower atmosphere or troposphere.

Volcanic activity may be contributing to the melting of the West Antarctic Ice Sheet. The West Antarctic Ice Sheet has many subglacial lakes beneath it, and geothermal heating is thought to contribute to the melting of the ice sheet's base. Subglacial volcanic activity and geothermal heating are important in providing subglacial meltwater, which lubricates the ice streams and facilitates fast ice flow. While a step-change in geothermal energy has not been observed to account for the extremely rapid recession at the ice-ocean interface, the extent and rate of melting caused by geothermal heating are very poorly known and currently not included in glaciological numerical models.

Furthermore, ice sheet melt in Antarctica could lead to more subglacial eruptions. As the unloading of ice sheets reduces pressure on magma chambers below the surface, the compressed magma expands and increases pressure on the magma chamber walls, potentially leading to eruptions. This process has been observed to increase the number and size of subglacial eruptions elsewhere on the globe. While these eruptions may not be visible on the surface, the heat from these eruptions can increase ice melting deep below the surface and weaken the overlying ice sheet, creating a feedback loop of reduced pressure and further volcanic eruptions.

Volcanic eruptions release CO2 and other gases into the atmosphere

Volcanic eruptions release carbon dioxide (CO2) and other gases, such as sulphur dioxide, into the atmosphere. CO2 is a greenhouse gas and is the primary gas blamed for climate change. While sulphur dioxide released in contemporary volcanic eruptions has occasionally caused detectable global cooling of the lower atmosphere, the carbon dioxide released has never caused detectable global warming of the atmosphere.

Volcanoes emit carbon dioxide in two ways: during eruptions and through underground magma. Carbon dioxide from underground magma is released through vents, porous rocks and soils, and water that feeds volcanic lakes and hot springs. In fact, much of the carbon dioxide released by volcanoes is emitted by the degassing of subterranean magma when the volcano is not erupting.

Several large volcanic eruptions during the past century have injected huge amounts of volcanic gas, aerosol droplets, and ash into the stratosphere. The climactic eruption of Mount Pinatubo on 15 June 1991, for example, injected a 20-million-ton sulphur dioxide cloud into the stratosphere. This caused the largest aerosol disturbance of the stratosphere in the twentieth century, cooling the Earth's surface for three years following the eruption by as much as 1.3 degrees Fahrenheit at its peak.

While large volcanic eruptions can inject significant amounts of carbon dioxide into the atmosphere, human activities emit 60 or more times the amount of carbon dioxide released by volcanoes each year. In 2015, human activities emitted roughly 40 billion metric tons of carbon dioxide, while volcanoes produce less than 1 billion metric tons annually. In 2010, human activities were responsible for a projected 35 billion metric tons of CO2 emissions, while volcanoes released less than a percent of that amount. In fact, several individual U.S. states emit more carbon dioxide in a year than all the volcanoes on the planet combined.

Frequently asked questions