What Is the Greenhouse Effect?
What is the greenhouse effect, and how does it work? The greenhouse effect is a phenomenon that happens when gases in Earth’s atmosphere trap heat from the Sun. The result of this process is that the Earth is significantly warmer than it would be if there were no atmosphere. The greenhouse effect is one of the factors that contributes to Earth’s being a pleasant place to live. To discover more about the greenhouse effect, check out this video!
How does the greenhouse effect work?
As you may guess from the name, the greenhouse effect operates in the same way as a greenhouse does. A greenhouse is a structure that is entirely made of glass, including the walls and roof. Growing plants in a greenhouse, such as tomatoes and tropical flowers, is a popular method of producing food. Even in the cold, a greenhouse maintains a comfortable temperature inside. Light streams into the greenhouse during the day and heats both its contents (plants and air) and the surrounding environment.
This is due to the fact that the greenhouse’s glass walls capture the heat emitted by the Sun.
- As a result of its glass walls, which retain the Sun’s heat, the greenhouse is able to keep plants warm — even on frigid nights.
- Gases in the atmosphere, such as carbon dioxide, act like a greenhouse’s glass roof in that they trap heat.
- During the day, the Sun beams through the atmosphere and illuminates everything.
- During the night, the Earth’s surface cools, releasing heat into the surrounding atmosphere.
- That’s what keeps the average temperature of our planet at a comfortable 58 degrees Fahrenheit (14 degrees Celsius).
- Image courtesy of NASA/JPL-Caltech
How are humans impacting the greenhouse effect?
The natural greenhouse effect of the Earth is being altered by human activity. The combustion of fossil fuels such as coal and oil contributes to the increase of carbon dioxide in our atmosphere. Increases in the amount of carbon dioxide and several other greenhouse gases in our atmosphere have been noticed by NASA. If the atmosphere contains an excessive amount of these greenhouse gases, the Earth’s atmosphere will begin to trap more and more heat. The Earth warms as a result of this.
What reduces the greenhouse effect on Earth?
Earth’s greenhouse is filled with plants, just like a glass greenhouse would be! Plants can contribute to the Earth’s ability to maintain a stable greenhouse effect. All plants, from the largest trees to the smallest phytoplankton in the ocean, take in carbon dioxide and release oxygen into the atmosphere. In addition, the ocean absorbs a significant amount of surplus carbon dioxide in the atmosphere. Unfortunately, the additional carbon dioxide in the ocean alters the water’s pH, making it more acidic in the process.
Many ocean organisms, such as particular shellfish and coral, can be harmed by acidic water, which is becoming more prevalent.
The major cause of coral bleaching is the warming of the ocean’s waters.
This snapshot depicts a brain coral that has been bleached. The warming of the seas is a major contributor to coral bleaching. Coral reef populations are also being harmed by ocean acidification. Image courtesy of the National Oceanic and Atmospheric Administration.
The greenhouse effect
Earth’s greenhouse is filled with plants, much like a glass greenhouse would be. Earth’s greenhouse effect can be countered through the usage of plants. Everything from enormous trees to small phytoplankton in the water need carbon dioxide to grow and releases oxygen to do so. As a bonus, the ocean absorbs a significant amount of carbon dioxide from the atmosphere. The additional carbon dioxide in the ocean, however, has an adverse effect on the water, making it more acidic. This is referred to as “ocean acidification” in scientific terms.
It is also possible that warming oceans, which is caused by an excess of greenhouse gases in the atmosphere, will be damaging to these creatures.
The brain coral in this shot has been bleached.
In addition, coral reef populations are being harmed by acidification of the seawater.
Earth’s greenhouse, like a glass greenhouse, is brimming with plants! Plants can contribute to the stabilization of the greenhouse effect on the planet. All plants, from the largest trees to the smallest phytoplankton in the ocean, take in carbon dioxide and release oxygen into the environment. The ocean also absorbs a significant amount of the extra carbon dioxide in the atmosphere. The extra carbon dioxide in the ocean, however, has changed the water’s pH, making it more acidic. This is referred to as “ocean acidification.” Many ocean organisms, such as particular shellfish and coral, can be harmed by more acidic water.
The major cause of coral bleaching is the warming of the ocean.
The warming of the seas is a significant contributor to coral bleaching.
Image courtesy of the National Oceanic and Atmospheric Administration (NOAA).
Which gases cause the greenhouse effect?
Earth’s greenhouse is filled with plants, much like a glass greenhouse would be. Plants can contribute to the stabilization of the greenhouse effect on Earth. All plants, from massive trees to microscopic phytoplankton in the ocean, take up carbon dioxide and release oxygen. The ocean also absorbs a significant amount of extra carbon dioxide in the atmosphere. Unfortunately, the extra carbon dioxide in the ocean causes the water to alter, making it more acidic. The term for this is “ocean acidification.” Many ocean organisms, such as some shellfish and coral, can be harmed by acidic water.
Warmer oceans are a major contributor to coral bleaching.
This snapshot depicts a bleached brain coral. The warming of the seas is a major contributing factor to coral bleaching. Coral reef populations are also threatened by ocean acidification. Photo courtesy of the National Oceanic and Atmospheric Administration
- Water vapour (H 2 O)
- Carbon dioxide (CO 2)
- Nitrous oxide (N 2 O)
- Methane (CH 4)
- Ozone (O 3)
- Are all examples of greenhouse gases.
Compared to carbon dioxide, CH 4 is 23 times more effective, and N 2 O is 296 times more effective when it comes to the amount of heat that they can absorb and re-radiate (known as their global warming potential or GWP). However, there is far more CO 2 in the atmosphere of the Earth than there is CH 4 or N 2 O. We cannot guarantee that all of the greenhouse gases we put into the atmosphere will remain there eternally. When it comes to carbon dioxide, for example, the amount of CO2 in the atmosphere and the amount of CO2 dissolved in the surface waters maintain balance since the air and water mix nicely at the ocean’s surface.
Anthropogenic greenhouse gases
Since the beginning of the Industrial Revolution in the mid-18th century, human activities have resulted in a significant rise in the amounts of greenhouse gases present in the atmosphere. As a result, recorded CO2 concentrations in the atmosphere are several times greater than they were before the industrial revolution. This graph depicts an overview of worldwide anthropogenic greenhouse gas emissions in 2017. The data are given in CO2-equivalents. Inventory of Greenhouse Gas Emissions and Sinks in the United States, 1990-2015 (EPA, 2017).
Main sources of anthropogenic greenhouse gases
Carbon dioxide concentrations are far greater currently than they have been at any time in the previous 750 000 years. The use of fossil fuels has increased the concentration of carbon dioxide in the atmosphere from roughly 280 parts per million (ppm) in pre-industrial times to more than 400 parts per million (ppm) in 2018. This represents a 40% rise in the number of people since the beginning of the Industrial Revolution. CO 2 concentrations are growing at a rate of roughly 2–3 parts per million (ppm) every year, and it is projected that they will exceed 900 parts per million by the end of the twenty-first century.
As a result, some experts advocate for limiting concentrations in order to keep temperature changes below +2 degrees Celsius.
When it comes to power and heat generation, the burning of coal, natural gas, and oil constituted the most significant single source of global greenhouse gas emissions in 2010.
In comparison, fossil fuels used in road, rail, aviation, and maritime transportation accounted for 14 percent of worldwide greenhouse gas emissions in 2010.
According to a United Nations estimate, livestock is responsible for around 14.5 percent of the total emissions. The following are the primary sources of emissions:
- Agriculture (45 percent)
- Production and processing of feed (39 percent)
- Emissions of greenhouse gases during cow digestion (10 percent)
- And decomposition of cow feces (10 percent).
It is believed that the remaining portion is due to the processing and transportation of animal products. In addition, changes in land and wetland usage, pipeline losses, and landfill emissions all contribute to higher amounts of CH 4 in the atmosphere. The usage of fertilizers can also result in greater levels of N 2 O in the environment. Agriculture is thought to be the primary driver of deforestation in the globe, accounting for around 80% of all deforestation. Source:Pixabay. When calcium carbonate is heated to produce lime and CO2, the process of cement manufacturing contributes CO2 to the environment.
- The cement business emits more than 900 kg of CO2 for every 1000 kg of cement produced, which is a significant quantity of CO2 emissions.
- In terms of CO2 emissions, the cement sector accounts for approximately 5% of worldwide anthropogenic CO2 emissions.
- Aerosols are microscopic particles floating in the atmosphere that can be formed when we use fossil fuels to heat our homes and power our vehicles.
- Naturally occurring aerosols can also be created by a variety of natural processes, such as forest fires, volcanic eruptions, and the release of isoprene by plants.
- Examples of cooling effects include sulphate aerosols produced by fossil fuel combustion, which reduce the quantity of sunlight that reaches the Earth’s surface and hence cool the planet.
- Tarvurvur’s volcanic ash dunes are located in Papua New Guinea.
- Aerosols scatter and absorb radiation in a direct and immediate manner.
- Taro Tayler is the source of this information.
The climate of a region is the pattern of weather that has developed over a long period of time. The only way to determine whether or not climate change has happened is via decades of meticulous monitoring and study. More information may be found here.
Impacts of climate change
Temperature increases have the potential to have an impact on agriculture, sea levels, and the frequency of extreme weather events.
We may learn about previous climate change by examining the evidence left behind in rocks, fossils, and changes in the landscape. More information may be found here.
The carbon story
The carbon cycle is a term used to describe the process by which carbon atoms are constantly transported from the atmosphere to the Earth and then returned to the atmosphere. More information may be found here.
The so-called “greenhouse gases” are really critical to maintaining a livable temperature on our planet; without them, the Earth would be around minus 17 degrees! The release of carbon dioxide by humans, known as anthropogenic or human-caused greenhouse gas emissions, is what is leading to an extra or amplified greenhouse effect.
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When water vapour, carbon dioxide, methane, and other gases are present in the atmosphere, the greenhouse effect causes the Earth’s surface and troposphere (the lowest layer of theatmosphere) to warm and become more humid. Water vapour has the greatest impact of any of these gases, which are collectively known as greenhouse gases. It is uncertain where the phrase “greenhouse effect” originated. French mathematician Joseph Fourieriis sometimes credited with coining the term “greenhouse effect” in 1824, based on his conclusion that the Earth’s atmosphere functioned in a similar way to a “hotbox”—that is, a heliothermometer (a wooden box with a transparent glass lid) developed by Swiss physicistHorace Bénédict de Saussure, which prevented cool air from mixing with warm air—and that the term “greenhouse effect” was Fourier, on the other hand, neither used the phrase “greenhouse effect” nor attributed atmospheric gases with keeping the planet warm.
When Svante Arrhenius published the first feasible climate model that showed how gases in the Earth’s atmosphere trap heat in 1896, he is often recognized with being the originator of the term “global warming.” At the beginning of his work, Worlds in the Making, Arrhenius refers to this “hot-house hypothesis” of the atmosphere, which would subsequently be known as the greenhouse effect (or greenhouse effect theory) (1903).
- Quiz on the Encyclopedia Britannica From the Lions and Lambs of March, we have April Showers.
- What is the coldest temperature?
- Put on your thinking caps—and, if it’s raining, your umbrella—and prepare to put your knowledge of weather and climate to the test in this online quiz.
- Due to the heating caused by the sun’s rays, the Earth’s surface emits some of this energy back into space as infrared radiation.
- The heated atmosphere then transmits infrared radiation back toward the Earth’s surface, creating a feedback loop.
- The average surface temperature of the Earth would be just approximately 18 degrees Celsius (0 degrees Fahrenheit) if not for the warmth provided by the greenhouse effect.
- Increased carbon dioxide concentrations have an impact on the Earth’s atmosphere and plant life, which should be investigated.
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- From the beginning of the Industrial Revolution to the end of the twentieth century, the quantity of carbon dioxide in the atmosphere grew by approximately 30%, while the amount of methane in the atmosphere increased by more than 100%.
- As a result of global warming, the Earth’s climate might change, resulting in new patterns and extremes of drought and rainfall, as well as the disruption of food production in some areas of the world.
Those in charge of editing the Encyclopaedia Britannica John P. Rafferty has changed and updated this article in the most recent version.
The Greenhouse Effect
Energy from the Sun that makes its way to the Earth may have difficulty re-entering the atmosphere and returning to space. The greenhouse effect causes a portion of this energy to become trapped in the atmosphere, where it is absorbed and released by greenhouse gases. The temperature of the Earth would be below freezing if the greenhouse effect were not there. It is, in part, a result of nature’s processes. The Earth’s greenhouse effect, on the other hand, is becoming stronger as more greenhouse gases are released into the atmosphere.
How Does the Greenhouse Effect Work?
Thermal radiation occurs when solar energy is absorbed at the Earth’s surface and returned to the atmosphere as heat. As heat travels through the atmosphere and is reflected back into space, greenhouse gases absorb a significant amount of it. Why do greenhouse gases absorb heat in the first place? Greenhouse gases have a more complicated structure than other gas molecules in the atmosphere, and their structure allows them to absorb heat more effectively. They reflect the heat back to the Earth’s surface, to another greenhouse gas molecule, or out into space, depending on their configuration.
- Here are some examples.
- Every one of these gas molecules is made up of three or more atoms.
- Finally, the radiation is released by the vibrating molecules, which is most likely absorbed by another greenhouse gas molecule in the process.
- It is nitrogen and oxygen that make up the majority of the gases in the atmosphere, and they are the ones that contribute to the greenhouse effect since they cannot absorb heat.
A Couple of Common Greenhouse Gases
- Carbon dioxide: Carbon dioxide molecules, which are made up of one carbon atom and two oxygen atoms, make up a minor proportion of the atmosphere, but they have a significant impact on climate. At the beginning of the Industrial Revolution in the mid-19th Century, there were around 270 parts per million (ppm) of carbon dioxide in the atmosphere at that time. The quantity is increasing as a result of the emission of carbon dioxide into the atmosphere caused by the burning of fossil fuels. Since 2015, the concentration has exceeded 400 parts per million (ppm). (For the most up-to-date readings, consult the NOAA Global Monitoring Laboratory.)
- Despite the fact that carbon dioxide molecules make up just a small portion of the atmosphere, they have a significant impact on the climate. Carbon dioxide molecules are composed of one carbon atom and two oxygen atoms. At the beginning of the Industrial Revolution in the mid-19th Century, there were around 270 parts per million (ppm) of carbon dioxide in the air. In addition, the quantity of carbon dioxide released into the atmosphere by burning fossil fuels is expanding. Since 2015, the concentration has consistently exceeded 400 parts per million (ppm). (For the most recent readings, consult the NOAA Global Monitoring Laboratory.)
shown above: (Left) The surface of the Earth, which has been warmed by the Sun, emits heat into the atmosphere. It is possible that some heat is absorbed by greenhouse gases such as carbon dioxide and subsequently emitted into space (A). Some of the heat is radiated directly into space (B). Approximately a portion of the heat collected by greenhouse gases is reflected back towards the Earth’s surface (C). (Right) With more carbon dioxide in the atmosphere later this century, more heat will be prevented by greenhouse gases, resulting in a warming of the entire world.
More Greenhouse Gases = A Warmer Earth
Despite the fact that greenhouse gases account for just a small proportion of the gases in the Earth’s atmosphere, they have a significant impact on climate. It is projected that the amount of the greenhouse gas carbon dioxide in the atmosphere will double sometime during the twenty-first century. Other greenhouse gases, such as methane and nitrous oxide, are also rising in concentration. As fossil fuels are used, the amount of greenhouse gases released into the atmosphere rises. These gases, together with other air pollutants, contribute to global warming.
When farm animals digest their food, for example, they emit methane gas into the atmosphere.
The presence of additional greenhouse gases in the atmosphere increases the likelihood that heat travelling through on its way out of the atmosphere will be blocked.
They then emit the heat they have generated.
Approximately half of the heat will be radiated away from the Earth, half of it will be absorbed by another greenhouse gas molecule, and half of it will end up back at the surface of the globe. With increased greenhouse gas emissions, heat will remain in the atmosphere, warming the globe.
5 things you should know about the greenhouse gases warming the planet
In a greenhouse, sunlight is allowed to enter but heat is kept in. The greenhouse effect depicts a comparable phenomena on a planetary scale, except that, instead of the glass of a greenhouse, some gases are boosting global temperatures at an increasingly rapid rate. The surface of the Earth collects slightly less than half of the sun’s energy, while the atmosphere absorbs 23% and the remaining 5% is reflected back into space by the atmosphere. Natural mechanisms guarantee that the quantity of entering and exiting energy is equal, which helps to maintain the stability of the planet’s surface temperature.
This energy is reflected back to the surface, where it is absorbed again.
Apratim PalTwo ladies are searching for their daily water supply on a bone-dry terrain that has been severely damaged by the drought.
2. Why does the warming matter?
Climate change is being exacerbated by this temperature increase, which has long-term negative consequences for the environment and a wide range of natural systems. One of the consequences is an increase in the frequency and severity of extreme weather events – such as floods, droughts, wildfires, and hurricanes – which harm millions of people and inflict billions of dollars in economic damages. Global warming induced by human activity threatens both human and environmental health, according to Mark Radka, Chief of the United Nations Environment Programme’s (UNEP) Energy and Climate Branch.
Despite a temporary dip caused by COVID-19, the latest UNEPEmissions Gap Report shows a rebound in emissions and predicts a disastrous global temperature rise of at least 2.7 degrees this century unless countries make significantly greater efforts to reduce emissions.
Photograph courtesy of Unsplash/Johannes Plenio In spite of the global economic downturn induced by the COVID-19 epidemic, carbon dioxide levels continue to rise to historic highs.
3. What are the major greenhouse gases?
Water vapour is the most significant contribution to the greenhouse effect on a global scale. Natural processes, on the other hand, are responsible for the majority of the water vapour in the atmosphere. Carbon dioxide (CO2), methane (CH4), and nitrous oxide (NOx) are the primary greenhouse gases to be concerned about. CO2 may linger in the atmosphere for up to 1,000 years, methane for around a decade, and nitrous oxide for about 120 years, according to the International Energy Agency. Based on measurements taken over a 20-year period, methane is 80 times more effective than CO2 in causing global warming, while nitrogen dioxide has a 280-fold higher potency.
- What is the source of these greenhouse gases produced by human activity?
- They contain mostly carbon, and when they are burned to generate energy, power vehicles, or heat, they release carbon dioxide into the atmosphere.
- It is estimated that cows, sheep, and other ruminants, which ferment their food in their stomachs, account for around 32 percent of all human-caused methane emissions.
- The majority of nitrous oxide emissions that are generated by humans come from agricultural operations.
- Fluorinated gases, such as hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride, are greenhouse gases (GHGs) that do not occur naturally in the environment.
- The others are employed in industrial and commercial settings.
It is estimated that the global warming potential of some fluorinated gases is up to 16,300 times larger than that of carbon dioxide during a 20-year period. Photograph by Unsplash/TJKWind farms provide electricity and help to lessen the dependency on coal-fired electricity.
5. What can we do to reduce GHG emissions?
The transition to renewable energy, the imposition of a carbon tax, and the phase-out of coal are all critical components of the effort to reduce greenhouse gas emissions. In the end, tougher emission-reduction objectives are required to ensure the long-term maintenance of human and environmental health. In the words of Mr. Radka, “we need to put in place robust policies that support our increased aspirations.” It is not possible to continue on the same route and expect different outcomes. “Action is required immediately.” During COP26, the European Union and the United States announced the introduction of the Global Methane Pledge, which would see over 100 countries commit to reducing methane emissions in the fuel, agricultural, and waste sectors by 30% by 2030, as part of a global effort to combat climate change.
Policies were put in place between 2010 and 2021 with the goal of reducing yearly emissions by 11 gigatonnes by 2030 compared to what would have happened otherwise.
Everyone can be a part of the solution and have an impact on change by making choices that have less negative environmental consequences.
Carbon dioxide in the atmosphere is at a record high. Here’s what you need to know.
Greenhouse gases, which trap heat from the sun, have kept the Earth’s temperature habitable for humans and millions of other species for thousands of years. However, those gases are now out of balance, and they threaten to significantly alter the kind of living creatures that can live on our planet—as well as where they may survive. Carbon dioxide levels in the atmosphere, which are the most damaging and ubiquitous greenhouse gas, are at their highest levels in recorded history. The primary reason that greenhouse gas levels are so high is that people have released them into the atmosphere by burning fossil fuels.
The greenhouse effect is the term used to describe this process of heat being trapped.
Svante Arrhenius, a Swedish physicist, was the first to establish a relationship between an increase in carbon dioxide gas emissions due to the combustion of fossil fuels and global warming.
Hansen testified before the United States Congress that “the greenhouse effect has been recognized and is influencing our climate at this very moment.” Climate change is the phrase used today by scientists to describe the complex adjustments in our planet’s weather and climate systems that are being caused by increasing greenhouse gas concentrations in the atmosphere.
Worldwide, governments and organizations, such as the Intergovernmental Panel on Climate Change (IPCC), a United Nations agency that records the most recent climate change science, are monitoring greenhouse gases, documenting their affects, and implementing remedies.
Major greenhouse gases and sources
Warming the Earth’s temperature by storing heat from the sun has allowed humans and millions of other species to thrive on the planet. The gases, on the other hand, are now out of balance, and they are threatening to significantly alter the kind of living creatures that may exist on our planet—as well as their distribution. Climate change is causing carbon dioxide concentrations in the atmosphere to reach the greatest levels ever recorded. Carbon dioxide is the most hazardous and common greenhouse gas.
- The gases absorb solar energy and help to maintain heat near to the Earth’s surface, rather than allowing it to escape into space like it would otherwise.
- It was in 1824 that French mathematician Joseph Fourier estimated that the Earth would be significantly cooler if it did not have an atmosphere that the greenhouse effect hypothesis was first proposed.
- The American climate scientist James E.
- Extreme weather events, shifting species populations and habitats, rising sea levels, and a variety of other consequences are all part of climate change, which includes more than just rising average temperatures, which we refer to as global warming.
Effects of greenhouse gases
Greenhouse gases have far-reaching consequences for the ecosystem and human health. Climate change is exacerbated by the fact that they trap heat, and they also contribute to respiratory ailments due to smog and air pollution. Excessive rainfall, food supply problems, and an increase in wildfires are all consequences of climate change, which is driven by greenhouse gas emissions. The regular weather patterns we’ve been accustomed to will shift; some species will become extinct, while others will relocate or flourish in number.
How to reduce greenhouse gas emissions
The global economy, from manufacturing to agriculture to transportation to power production, all contributes to greenhouse gas emissions, and as a result, every sector of the global economy, from manufacturing to agriculture to transportation to power production, must transition away from fossil fuels if we are to avoid the worst effects of climate change. The Paris Climate Agreement, signed in 2015, brought countries from all around the world together to recognise this truth. The following are the major emitters who will see the most significant changes: A total of twenty countries are responsible for at least three-quarters of the world’s greenhouse gas emissions; China, the United States, and India are among those in the forefront.
They include the substitution of fossil fuels with renewable energy sources, the improvement of energy efficiency, and the imposition of a price on carbon emissions in order to discourage their use.
The total amount of carbon left to use up is 2.8 trillion metric tons.
To be sure, adopting methods of extracting CO2 from the atmosphere is necessary to achieve the IPCC’s 1.5 or 2 degree Celsius global temperature rises objectives, but there are other ways to achieve these goals as well.
Planting trees, maintaining existing forests and grasslands, and absorbing CO2 from power plants and factories are some of the options available.
What is the Concern about Greenhouse Gases and the Greenhouse Effect?
The average temperature at the surface of the Earth would be 0 degrees Fahrenheit if it did not have an atmosphere and the greenhouse effect to keep it warm. However, if the amount of greenhouse gases released exceeds a certain threshold, the temperature might rise beyond control. A good example of this is the planet Venus, where greenhouse gases are plentiful and the average surface temperature is more than 855 degrees Fahrenheit (457 degrees Celsius). It is possible to hear individuals refer to the greenhouse effect as though it were a negative phenomenon.
- As a result of the increasing greenhouse effect caused by our present emissions of greenhouse gases into the atmosphere, we are seeing this phenomenon.
- Carbon dioxide, the most significant greenhouse gas, is released naturally and through the combustion of fossil fuels and remains in the atmosphere for an extended period of time.
- Climate experts are extremely concerned about carbon dioxide because the greater the amount of carbon dioxide in the atmosphere, the hotter the world will get, causing the Earth’s climate to change.
- This has been recognized and understood by scientists for more than a century, and it has been proven by measurements and laboratory studies.
What Is the Greenhouse Effect?
There are just a few things you need to know about the Greenhouse Effect and why it is so crucial for the Earth in order to grasp the fundamentals of the phenomenon. Some of these things are probably already familiar to you. Given that standing in sunshine feels warmer than standing in shade, you may infer that the light (radiant energy) the sun emits contains energy that can be used to warm an object—in this case, you. While most objects emit radiant energy that cannot be seen, you may occasionally feel this energy radiating from them, even if you cannot see it.
- Although you may conceive of what you are feeling as “heat,” it is more realistic to think of it as a type of invisible light called “infrared radiation,” which heats your skin in the same way that sunshine does.
- Remember that you can easily tell the difference between a warm object and a hot one by placing your hand near the objects and experiencing the difference in heating effects on your skin.
- The same way that sunlight heats your skin, it also warms the surface of the Earth.
- Instead, the Earth cools down as it absorbs energy.
- The amount of infrared radiation energy emitted by the Earth is determined by the temperature of the planet.
- For billions of years, the greenhouse effect has kept the average temperature of the Earth far higher than it would otherwise have been, allowing life as we know it to develop.
- The graph below depicts how greenhouse gases cause the Earth to be warmer than it would be if they were not there.
Almost all of the remaining energy is reflected, mostly by clouds in the sky and ice and snow on the surface, rather than absorbed.
The straight red line extending from the surface of the Earth into the atmosphere indicates the proportion of emitted infrared radiation that goes into space via the atmosphere without being altered or degraded by the atmosphere.
The capacity of greenhouse gases to absorb and re-emit infrared radiation is a crucial need for their existence.
Some of the re-emitted energy either remains in the atmosphere or returns to the surface, where it heats the lower atmosphere and the surface of the Earth.
As a result of this absorption-emission process involving greenhouse gases, less energy exits the atmosphere than is released by the Earth’s atmosphere.
The surface of the Earth must be warmer than –18 degrees Celsius in order for this amount of energy to escape from the Earth’s greenhouse atmosphere.
In other words, the same amount of infrared radiant energy was leaving the atmosphere as was being absorbed at the surface by the sun’s radiant energy was leaving the atmosphere.
Increasing the amount of greenhouse gases in the atmosphere reduces the amount of infrared radiation energy that escapes the atmosphere.
This means that in addition to being responsible for maintaining the climate necessary for life on Earth, the greenhouse effect is also responsible for the Earth being warmer than it was before humans began burning vast quantities of fossil fuels.
U.S. Energy Information Administration (EIA)
Many of the chemical substances found in the earth’s atmosphere have the ability to behave as global warming agents. The sun shines on the earth’s surface, and some of the energy is reflected back into space as infrared radiation (heat). Carbon dioxide and other greenhouse gases absorb infrared radiation and trap its heat inside the atmosphere, leading to global warming and climate change as a result of the greenhouse effect. A wide range of gases display these greenhouse characteristics. A number of gases are created both naturally and as a result of human activity.
The world would be too cold to support life as we know it if it didn’t have naturally produced greenhouse gases to keep it warm.
Source: Adapted from the Environmental Protection Agency of the United States (public domain)
What are the types of greenhouse gases?
- Carbon dioxide (CO 2), methane (CH 4), nitrous oxide (N 2 O), and other industrial gases include the following:
- Hydrofluorocarbons (HFCs)
- Perfluorocarbons (PFCs)
- Sulfur hexafluoride (SF 6)
- Nitrogen trifluoride (NF 3)
- Hydrofluorocarbons (HFCs)
Water vapor and ozone are two more greenhouse gases that are not included in either the United States or international greenhouse gas inventories. In the atmosphere, water vapor is the most prevalent greenhouse gas; nevertheless, most scientists think that the water vapor created directly by human activities contributes just a small proportion to the total amount of water vapor in the atmosphere. Therefore, the Energy Information Administration (EIA) of the United States does not provide estimates of water vapor emissions.
- In nature, ozone exists naturally at higher heights in the atmosphere (the stratosphere), where it prevents damaging ultraviolet (UV) radiation from reaching the earth’s surface, which is destructive to both plant and animal life.
- Production and use of many industrial gases that deplete the atmosphere’s ozone layer and cause holes in the ozone layer are prohibited or tightly controlled in the United States and other nations across the world.
- In the lower atmosphere (the troposphere), ozone is hazardous to human health because it is a carcinogen.
- The most recent revision was made on July 15, 2021.
Main Greenhouse Gases
The greenhouse effect, which regulates the temperature of the Earth throughout geologic time, is caused by a variety of gases. The quantity of these gases in the atmosphere may fluctuate in small ways, resulting in temperature variations that can make the difference between the icy ages when mastodons roamed the Earth and the searing heat in which the dinosaurs thrived. The strength of the greenhouse effect is determined by two features of the gases in the atmosphere. Its “radiative efficiency” is the capacity of a material to absorb and radiate energy (the first factor).
Incorporating these characteristics into the Global Warming Potential (GWP), which is a measure of the radiative effect (i.e., the strength of their greenhouse effect) of each unit of gas (by weight) over a specified period of time, expressed in terms of the radiative effect of carbon dioxide, is important (CO 2).
Gases with high global warming potentials (GWPs) will warm the Earth more than an equal amount of CO 2 over the same time span.
Following is a table containing the atmospheric lifespan and global warming potential (GWP) values for important greenhouse gases derived from the Fifth IPCC Assessment Report (AR5), which was published in 2014.
Despite the fact that carbon dioxide has a relatively modest global warming potential (GWP) when compared to other key greenhouse gases, the huge rise in its atmospheric concentration produced by humans is responsible for the vast bulk of global warming.
Similarly, methane is responsible for a significant percentage of recent warming despite having a global warming potential (GWP) that is far lower than that of numerous other greenhouse gases. This is because methane emissions have grown dramatically in recent years.
|Greenhouse gas||Chemical formula||Global Warming Potential, 100-year time horizon||Atmospheric Lifetime (years)|
* Because carbon dioxide flows at different rates throughout the earth’s system, it is impossible to establish a single lifespan estimate for it. There will be a rapid absorption of some carbon dioxide, while other carbon dioxide will linger in the atmosphere for thousands of years. The relative concentrations of these key greenhouse gases, as well as their sources, are shown in the table below. The production of some gases (such as CO 2) is a consequence of both natural and human-induced processes, whilst others (such as hydrofluorocarbons) are solely the result of human-induced industrial activities.
Parts per billion (ppb) are used to represent the concentrations in the atmosphere (ppb).
|Greenhouse gas||Major sources||Pre-industrial concentration (ppb)||2011 concentration (ppb)|
|Carbon Dioxide||Fossil fuel combustion; Deforestation; Cement production||278,000||390,000|
|Methane||Fossil fuel production; Agriculture; Landfills||722||1,803|
|Nitrous Oxide||Fertilizer application; Fossil fuel and biomass combustion; Industrial processes||271||324|
|Sulfur Hexafluoride||Electricity transmission||0.0073|
|Nitrogen Trifluoride||Semiconductor manufacturing||0.00086|
The Rise of Atmospheric Carbon Dioxide
Despite the fact that carbon dioxide is relatively stable in the Earth’s atmosphere, individual carbon dioxide molecules are in a state of near continual flow from many reservoirs, including the surface ocean, terrestrial biota, and the atmosphere. Even though a generally quoted estimate for CO2lifetime is 100 years, it should be noted that this figure only represents a percentage of the total lifespan of carbon dioxide in the atmosphere. Some of the material has a lifespan of up to 1,000 years (IPCC 2007, FAQs).
The enhanced greenhouse effect
We would be living in an extremely cold environment if it weren’t for the greenhouse effect; the average temperature on the planet would be minus 18°C, rather than the 15°C we are used to experiencing. So, what exactly is the greenhouse effect, and how does it contribute to the Earth being around 33 degrees Celsius warmer?
The natural greenhouse effect
This is a phenomena generated by gases naturally existing in the atmosphere, which affects the behavior of heat energy radiated by the sun. The natural greenhouse effect is caused by gases naturally present in the atmosphere. Sunlight (shortwave radiation) is a kind of electromagnetic energy that travels through the atmosphere and is absorbed by the Earth’s surface. When this happens, the Earth’s surface becomes warmer, and the Earth then radiates part of this energy back into space (as infrared or longwave radiation).
It then radiates out in all directions, allowing some energy to escape into space, but it is far less than would have escaped had the atmosphere and its greenhouse gases not been there.
The greenhouse effect is named such because it is comparable to the way a greenhouse operates.
Because only a portion of the sun’s energy is allowed to leave through the greenhouse’s glass (or similar) panes, the temperature within the greenhouse is increased, making the atmosphere for the plants inside a warmer and more friendly setting.
Earth’s energy balance
When the rate at which energy is absorbed by the Earth is nearly balanced by the rate at which energy is radiated back into space, Earth maintains a state of equilibrium and a stable temperature, which is known as a state of equilibrium and a stable temperature, respectively. For as long as the amount of greenhouse gases in the atmosphere remains constant and the pace at which energy from the sun arrives remains constant, this balance will be maintained. Natural greenhouse effect kept the average temperature of the Earth’s surface at around 15 degrees Celsius over the centuries preceding the beginning of the Industrial Revolution in the late 1700s.
Billy Wilson / Flickr is the photographer behind this image.
The composition of the atmosphere is changing
Earth’s atmosphere is made up of 78 per cent nitrogen and 21 per cent oxygen. Only approximately 1 per cent is made up of natural greenhouse gases, yet this comparatively tiny amount of gas makes a tremendous influence. The Industrial Revolution introduced new industrial processes, a rise in the combustion of fossil fuels, more widespread agriculture, and a significant growth in the world’s population. Because of this tremendous growth in human activity, huge amounts of greenhouse gases have been released into the atmosphere, and this process is currently occurring.
Although the Earth’s atmosphere has changed significantly over geological time, and high concentrations of greenhouse gases have existed in the Earth’s atmosphere in the past, the Earth has never before experienced such a significant increase in the amount of greenhouse gases in the atmosphere in such a short period of time.
Note that the statistics above utilize a composite of both instrumental and proxy data.
The enhanced greenhouse effect and climate change
Global average surface temperatures have risen as a result of the disruption to the Earth’s climatic balance caused by higher concentrations of greenhouse gases in the atmosphere. The increased greenhouse effect is the name given to this phenomenon. While scientists agree that the amounts of greenhouse gases in the atmosphere and the average global temperature are rising, they are less clear about the long-term repercussions of these changes. Mathematical models are used by scientists to better comprehend this phenomenon.
- According to the simulations, the Earth’s surface will get warmer.
- These shifts will have further ramifications for global agriculture, biodiversity, and human health in the future.
- Since the beginning of the twentieth century, the average global temperature has risen by around 0.7 degrees Celsius.
- More significantly, even a slight but persistent increase in temperature over time can have a considerable influence on large-scale natural characteristics such as ice sheets or forest cover.
- The area of Arctic ice, snow cover, and glacier volumes have all reduced, while sea level has risen.
- Warmer ocean temperatures will have an impact on marine ecosystems and can put a strain on coral reefs as a result.
In turn, this has altered the chemistry of the ocean’s surface, a process known as ocean acidification, and it has the potential to cause a slew of other issues for marine life.
Predicting the future is difficult
While the fundamental physics of the greenhouse effect is pretty well known, forecasting the course of events in the future is challenging due to our limited understanding of future greenhouse gas emissions as well as the detailed behavior of the atmosphere and oceans, among other factors. Having several interconnected “feed-back” mechanisms at work, the climate system is extraordinarily complex, with the potential to either magnify or lessen the initial impact.
A national and international issue
An increase in global temperature would have consequences for the whole world, and hence for every country on the earth. As a result, it has become a global issue that requires worldwide investigation and solution. Despite the fact that Australia’s contribution to global CO 2emissions in 2012 was barely approximately 1 percent, our per capita CO 2production places us among the top OECD nations. At the United Nations Conference on Environment and Development in Rio de Janeiro in 1992, Australia and more than 150 other nations signed the United Nations Framework Convention on Climate Change, which became effective in 2004.
- However, due to the very sensitive political and economic nature of climate change concerns, little progress has been accomplished in terms of lowering greenhouse gas emissions on a worldwide scale.
- Prior to the Industrial Revolution, CO 2 concentrations in the atmosphere were around 280 parts per million.
- This is the highest level of CO 2 in the atmosphere since approximately 35 million years ago.
- It was almost clear that there were no humans in sight; woolly mammoths and other huge beasts roamed the world.
Global emissions per capita
The CO 2 emissions per person (measured in metric tons of carbon) from fossil-fuel combustion, cement manufacture, and gas flaring activities were shown in the graph above in 2010. Carbon Dioxide Information and Analysis Center is the source of the data.
The greenhouse effect is being studied in depth by Australian scientists in a variety of areas. Some scientists are attempting to establish climatic patterns, while others are attempting to model the impact of the greater greenhouse effect on Australia’s climate and economic conditions. Others are working on the Antarctic ice cap, trying to figure out what effects the increased greenhouse effect could have there. There have been contributions from a number of Australian scientists to the World Climate Research Programme as well as to the preparation of the Intergovernmental Panel on Climate Change Assessment Reports.
Climate change is one of the most serious problems that humanity is now facing. The decisions we make today will have consequences for generations to come, both now and in the far future. NASA provided the image.