Geology And Geophysics

Understanding how Volcanoes Produce so much Greenhouse Gas

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"Understanding how Volcanoes Produce so much Greenhouse Gas"
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People know that volcanoes have produced incredible amounts of matter that has been ejected into the atmosphere because our current atmosphere came from volcanic eruptions in the first place. However, volcanoes are not known for producing more greenhouse gases than humans. Humans win the greenhouse production sweepstakes by a mile. According to the United States Search and Rescue Task force:

"The Earth's first oceans and atmosphere formed from the gases given off by volcanoes.  In turn, oceans and an atmosphere created the environment that made life possible on our planet.  Volcanoes have also shaped the Earth's landscape.  Many of our mountains, islands, and plains have been built by volcanic eruptions."

First, this article will look at volcanoes and their power to eject solid particles that affect the atmosphere. Then human-caused emissions will be examined and the CO2 contributions of the two will be  compared to show that volcanoes tend to cause global cooling, while human CO2 emissions causes global warming. 

Volcanoes = particulate matter and gases and global cooling

According to Our Amazing Planet, an amazingly volcanic period occurred 120 million years ago. The Greater Ontong Java Event is believed to have involved 1 percent of the Earth's surface with ongoing eruptions that released magma and chemicals to the atmosphere for seven years.

With so much power to release greenhouse gases, it seems that volcanoes would be the bigger culprits than humans. But volcanoes emit more particulate matter than CO2. 

Volcanoes are measured by the Volcanic Explosivity Index (VEI) where a scale goes from 1 to 8. Each succeeding VEI is 10 times greater than the last. In relation to the VEI, take a look at the top ten volcanic explosions in history.

The last volcanic event of VEI 8 was 10,000 years ago. The past 4,000 years hold the most powerful volcanoes in human recorded history, but the last 400 years hold the most information. The greatest eruptions in recent history have been at around VEI 6 and have ejected massive amounts of ash and gas into the atmosphere, along with rock that can be so fine that it is invisible to the naked eye. The resulting acid rain can burn people. The solids can blanket huge areas, wiping out fertile lands and changing the shape of the Earth's surface in big ways. Here are some examples:

1600, Huaynaputina, Peru. This VEI 6 eruption is believed to have affected the global atmosphere.

1883, Krakatoa, Sunda Strait, Indonesia. This VEI 6 eruption is believed to have affected the global atmosphere and created red skies as far away as Europe.

1912, Novarupta, Alaska. This VEI 6 sent 3 cubic miles or 12.5 cubic km of magma and ash into the atmosphere.

1991, Mount Pinatubo, Luzon, Philippines. This VEI 6 sent a column of ash that rose up 22 miles (35 km) in the atmosphere.

Ongoing. Ambrym Island, Republic of Vanuatu. This VEI 6+ created a caldera 7 miles wide. This is one of the world's most active volcanoes and has erupted almost 50 times since 1774.

Volcanoes are more inclined to release particles that cause global cooling. "The haze effect" happens where solar radiation is blocked out by the particles! The amount of CO2 released by volcanoes is vastly smaller than the amount of particulate and sun blocking matter. The particulate matter and subsequent atmospheric cooling would cancel out any CO2 caused atmospheric warming.

Humans = CO2 and global warming from a greenhouse like effect

According to Hyperphysics, "...the greenhouse effect has been widely used to describe the trapping of excess heat by the rising concentration of carbon dioxide in the atmosphere. The carbon dioxide strongly absorbs infrared and does not allow as much of it to escape into space."

The onset of the latest round of global warming relates to the beginning of the Industrial Revolution when burning coal and fossil fuels began to explode in volume. The resulting release of CO2 has grown by exponential levels. Has the human population developed the capability to create a global "greenhouse effect"? Yes.

Humans have developed the capability to release at least 150 times more CO2 than volcanoes have. According to T.M.Gerlach (1991, American Geophysical Union), if it were not for the volcanic eruptions that have gone on in recent history, global warming from human CO2 emissions might not have been partially cancelled by the volcanic effects of global cooling.

Global Warming, Cooling, Climate and Local Weather

It must be repeated again and again that global cooling and warming applies to the temperature of the entire atmosphere of Earth. This is calculated by looking at data over the longest periods of time possible, the shortest duration being about ten years. Climate applies to the entire planet. Weather applies to a specific place and time. So yes, there can be record cold in one specific place while there is global warming, and there can be record heat in another specific place when there is global cooling. 

In summary, humans have been found to be capable of producing more CO2 than volcanoes to heat up the atmosphere. Volcanoes tend to contribute particulate matter that causes global cooling, not warming. This belies claims that all of today's global warming is from natural causes and that humans can continue to indiscriminately burn fossil fuels. There is no doubt that humans have good reasons for finding alternative power and fuel sources as quickly as possible.

More about this author: Elizabeth M Young

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