The Chemistry of the Greenhouse Effect

Introduction

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The greenhouse effect remains one of the reasons Earth is habitable to humans and other organisms. It relies on mainly on five gases, water vapor, carbon dioxide, methane, ozone, and nitrous oxide. These gases work together to trap infrared radiation within the Earth’s atmosphere in order to maintain temperatures. I chose this topic because recent climate shifts are the responsibility of changes in the greenhouse effect. As humans have begun to deforest the land, burn fossil fuels, and increase methane through agriculture, Earth has likewise warmed. It is important to respond to these temperature changes, because they pose a threat to coastal cities and organisms across the world. My life is affected by the greenhouse effect because changes in it will impact my life in the future. Some scientists believe that current trends will submerge port cities by the year 2100. It is an important responsibility of the rising generation to form a plan of action to reverse current climate trends.

Composition of ...

Water Vapor: H2O

Accounts for 36%-70% of the greenhouse effect

Melting Point: 0.00° C

Boiling Point: 99.98° C

Carbon Dioxide: CO2

Accounts for 9%-26% of the greenhouse effect

Melting Point: -56.6° C

Boiling Point: -78.5° C

Methane: CH₄

Accounts for 4%-9% of the greenhouse effect

Melting Point: -56.6° C

Boiling Point: -78.5° C

Ozone: O₃

Accounts for 3%-7% of the greenhouse effect

Melting Point: -192.9° C

Boiling Point: -112° C

Nitrous Oxide: N2O

Contribution of greenhouse effect unlisted

Melting Point: -90.86° C

Boiling Point: -88.48° C



Main Chemicals, Compounds, Components

Water Vapor: On average water vapor accounts for 60% of the greenhouse effect. Water vapor works to absorb infrared radiation as it is radiated from Earth. Humans have contributed to atmospheric warming since the initiation of the industrial revolution. This is because increasing levels of carbon dioxide in the Earth’s atmosphere causes warming via the greenhouse effect. This small amount of warming triggers heightened levels of water vapor in the atmosphere. The entire cyclical process is labeled the ‘positive feedback loop.’ Nonetheless, there is a large amount of scientific uncertainty when discussing this subject. Heightened levels of water vapor also result in the formation of clouds, which reflect the solar radiation. As a result, the role of water vapor continues to be investigated by scientists across the world.

 

Carbon Dioxide: Carbon dioxide traps heat in the Earth by absorbing infrared light, which prevents heat from escaping. This creates convection which keeps Earth’s temperatures relatively stable. While it is not the largest contributor to the greenhouse effect, Carbon Dioxide contributes the most to global warming. As humans burn fossil fuels, gas, coal, and oil, global levels of atmospheric carbon dioxide increase. In 2007, the IPCC released a global assessment of relative influence of aerosol gases in the atmosphere. This study determined that carbon dioxide by farm assumed the largest role in global warming. Though some gases possess higher heat-trapping abilities, the abundance of carbon dioxide quantifies its effect. Additionally, carbon dioxide remains present in the atmosphere for prolonged periods of time. Thus, the climate created now will remain for decades to come.



Chemistry's Role

Greenhouse gases are naturally occurring in the atmosphere. However levels of greenhouse gases can be increased through human activities. Entering the atmosphere through Earth’s water bodies, water vapor contributes to a large percentage of the greenhouse effect. Indirectly, humans increase the atmospheric levels of water vapor.  As humans contribute carbon dioxide and methane to the atmosphere, the natural associated warming causes a temperature increase which evaporates additional water. Furthermore, carbon dioxide enters Earth’s atmosphere through the consumption of fossil fuels and through volcanic eruptions and activity. These levels are increased through deforestation. Deforestation has likewise decreased photosynthesis which in turn has contributed to atmospheric carbon dioxide. Furthermore, methane is a hydrocarbon gas that is created through human activities and natural sources. Methane enters the atmosphere through the decomposition of waste and manure. Per molecule, methane contributes most to the greenhouse effect, and it is 84 time more powerful than carbon dioxide. Nitrous oxide is also created naturally and artificially through soil cultivation, organic fertilizers, the utilization of fossil fuels, and the production of nitric acid. The greenhouse effect is a result of the passing of electromagnetic waves through electrically charged particles. Because most particles in Earth’s atmosphere don’t possess electrical charges, Earth gains this effect from polar molecules. The imbalance of polar molecules engenders a lopsided state which can absorb infrared radiation. Gases which behave this way include water, ozone, and nitrous oxide.  On the other hand, carbon dioxide is not a polar molecule. Nonetheless, due to the constant motion and collisions between gas molecules, these gases remain in electrically lopsided states.


Background Research

Despite how the Earth and moon are relatively the same distance from the sun, the Earth experiences a higher degree of temperature regulation. To illustrate, the moon regularly fluctuates between -170 degrees celsius and 100 degrees celsius. In sharp contrast, the lowest and highest temperatures ever recorded on Earth are -89 degrees celcius and 71 degrees respectively. This concept which engenders the possibility of life on Earth is primarily attributed to the greenhouse effect. The greenhouse effect is caused by the Earth’s atmospheric gases. During the day, this phenomenon shields our planet from violent energetic rays, while during the night it traps infrared radiation which maintains the planet’s biologically friendly temperatures.

The greenhouse effect is a direct result of the Earth’s greenhouse gases. Water vapor accounts for 36-70% of the greenhouse effect, carbon dioxide accounts for 9-26%, methane accounts for 4-9%, and ozone accounts for 3-7%. The vast ranges of these percentages account for the overlapping degrees of absorption and emission bands. While all atmospheric gases work to absorb infrared radiation, some gases fail to contribute to the greenhouse effect. Only 1% of atmospheric gases seizes 90% of the exiting heat.

Since the beginning of the Industrial Revolution, human activities, including the burning of fossil fuels, have begun to add carbon dioxide to the atmosphere. To compensate for the energy imbalance, the earth has begun to emit an increased level of infrared radiation which contributes to global warming. Thus, the greenhouse effect directly causes the warming of the Earth. In 1896, a Swedish chemist named Laureate Svante Arrhenius raised controversy over a posed question about climate change on his monumental paper. Despite its initial contention, the paper became a primary contributor to research exploring the effect of increasing carbon dioxide levels on global climate change.

Though the debate over global warming remains heated today, these arguments primarily remain in media sources and fail to be found in scientific studies and literature. The scientific debate over global warming envelops the long term environmental consequences of the Earth’s warming. The global concern led to the Paris Agreement of 2016, in which nearly 200 countries signed a pledge to reduce greenhouse gas emissions. Additionally, the agreement pursues the goal of preventing the temperature from rising above 1.5 degrees celsius. Though the Paris Agreement marks a fundamental and vital shift in the world’s climate action, even an increase in 1 degree celsius poses a threat to coastal cities and islands across the world.


Resources

http://bouman.chem.georgetown.edu/S02/lect23/lect23green.html

  • Key Terms relating to Solar Energy

    • Solar Constant

    • Albedo

    • Radiative temperature

  • Solar Radiation Spectrum Illustration

  • Earth’s Energy Budget Illustration

  • Greenhouse molecules

https://www.acs.org/content/acs/en/climatescience/greenhousegases.html

  • Overview on Greenhouse Gases

  • Information on Nobel Laureate Svante Arrhenius and the initial controversy surrounding the greenhouse effect

  • The effects and consequences of Greenhouse Gases on the atmosphere

https://www.acs.org/content/acs/en/climatescience/climatesciencenarratives/what-is-the-greenhouse-effect.html

  • General explanation of Greenhouse Effect

  • How greenhouse gases keep the Earth warm and how the balanced temperatures are maintained

  • The effects of human activities on the Greenhouse Effect

https://www.youtube.com/watch?v=sTvqIijqvTg

  • Comparison of the temperatures on Earth and the moon

  • Composition of Earth’s atmosphere

  • How Earth’s atmosphere absorbs energy

    • Water, Ozone, and Nitrous Oxide

    • Carbon Dioxide and Methane

  • Overview on Earth’s climate changes over time

https://en.wikipedia.org/wiki/Greenhouse_effect

  • Importance of the greenhouse effect on Earth

  • History of the greenhouse effect

  • Mechanics of the greenhouse effect

  • Composition of greenhouse gasses

  • The role of the greenhouse effect on climate change

  • Similarities between greenhouses and the greenhouse effect

https://www.ucar.edu/learn/1_3_1.htm

  • How the greenhouse effect makes Earth a suitable place for life

  • Solar Radiation on Earth

  • How greenhouse gases keep Earth warm

  • Albedo and how it relates to the greenhouse effect

http://www.livescience.com/37743-greenhouse-effect.html

  • General Explanation and Overview of the greenhouse effect

  • The Balance of the greenhouse effect

  • Incoming and Outgoing energy on Earth

  • Greenhouse gases and global warming

  • Reversing a damaged greenhouse effect

https://www.acs.org/content/acs/en/climatescience/climatesciencenarratives/its-water-vapor-not-the-co2.html

  • Water Vapor and the greenhouse effect

  • The relationship between water vapor and other atmospheric gases

https://www.nasa.gov/topics/earth/features/vapor_warming.html

  • Water Vapor in climate change

  • How CO2  and water vapor contribute to global warming

  • AIRS instrument’s role in observing climate change

http://www.sjsu.edu/faculty/watkins/watervapor01.htm

  • Water Vapor in climate change

  • Positive Feedback Loop

  • Interactions between CO2  and water vapor

  • The burning of gasoline and fuel

  • Withdrawals from aquifers

  • Irrigation

  • Measuring Greenhouse Gases

https://en.wikipedia.org/wiki/Water_vapor

  • Properties of water vapor

    • Melting Point

    • Boiling Point

    • Chemical Formula

https://en.wikipedia.org/wiki/Carbon_dioxide

  • Properties of carbon dioxide

    • Melting Point

    • Boiling Point

    • Chemical Formula

https://en.wikipedia.org/wiki/Ozone

  • Properties of ozone

    • Melting Point

    • Boiling Point

    • Chemical Formula

https://en.wikipedia.org/wiki/Nitrous_oxide

  • Properties of nitrous oxide

    • Melting Point

    • Boiling Point

    • Chemical Formula

http://www.ucsusa.org/global_warming/science_and_impacts/science/CO2-and-global-warming-faq.html#.WFW8UaIrK3U

  • Carbon dioxide’s influence on the world climate

  • The warming trend

  • IPPC Study

  • Why carbon dioxide is trapped in the atmosphere

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/grnhse.html

  • Carbon dioxide’s role in the greenhouse effect

  • Convection

https://en.wikipedia.org/wiki/Global_warming_controversy

  • Debate of global warming

http://www.nature.org/ourinitiatives/urgentissues/global-warming-climate-change/the-paris-agreement-what-does-it-mean.xml

  • Paris Agreement

  • Goals of the Agreement

  • Participating countries


About the Author

Sophia Whitworth is a junior at Billings Senior High School. At school, she is involved in STEM Society, Student Council, Platinum Program, Interact Club, Spanish Club, Key Club, and has lettered in Cross Country 3 times. She also takes piano and percussion lessons and plays in the Senior High Symphonic Band and Philharmonic Orchestra. When Sophia finds free time, she enjoys running, biking, giving tours at the Moss Mansion, spending time with her friends, and traveling with her family. After she graduates, Sophia plans to go to college to double major in Spanish and Biology and afterwards pursue medical school.











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