The greenhouse effect is the process by which a planet's atmosphere allows solar radiation from the Sun to pass through, but instead prevents or hinders the exit of thermal energy from the planet.
It is called the greenhouse effect because of its similarity to the way greenhouses work. These systems are able to retain heat inside. The difference is that the greenhouse uses glass and not gases from the atmosphere to retain heat.
When we talk about the greenhouse effect, we are almost always referring to the effect produced on planet Earth. However, it also occurs in a similar way on other planets such as Venus and Mars.
Human activities and the main non-renewable energy sources have caused an excessive increase in the greenhouse effect. One of the advantages of renewable energies such as solar energy is that they do not emit gases. Clean energy is a good alternative to counteract these effects.
What is the greenhouse effect?
When solar radiation reaches the Earth's atmosphere, part of this radiation is reflected as if the Earth's surface were a mirror. Another part is absorbed and enters the atmosphere.
Most of the radiation that has managed to enter the atmosphere reaches the Earth's surface. This causes the surface to heat up. Some of this heat is then released as radiation, but at longer wavelengths than the original solar radiation.
Of the infrared radiation emitted by the Earth's surface, only a significant portion will be able to pass back through the atmosphere and go out into space. About 90%. The rest heats the gases in the atmosphere and its heat energy stays there. The planet is enveloped by a set of hot gases that contribute to warming it.
The atmosphere has the characteristic that it absorbs outgoing infrared radiation more easily than the visible radiation received from the Sun. This is what makes the Earth warmer than it would be without an atmosphere.
This event is what causes the planet Earth to reach temperatures compatible with life. The greenhouse effect is therefore a natural phenomenon of the atmosphere. If the heat were not retained in the atmosphere, the Earth would freeze.
4 Causes of the greenhouse effect
1. Greenhouse gases (GHG)
Some gases, such as carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O) and fluorinated gases, have the ability to trap heat in the atmosphere.
These gases form a kind of "thermal blanket" that prevents part of the heat that the Earth receives from the sun from escaping into space.
2. Human activities
There are many human activities that cause this effect. Below I show you the most important ones:
- Burning fossil fuels : Burning coal, oil and gas to generate energy or power vehicles releases large amounts of CO₂. It is the main cause of the increase of this gas in the atmosphere.
- Deforestation : Trees absorb CO₂, but massive logging reduces this natural ability to "clean" the atmosphere. In addition, burning or decomposing wood releases even more CO₂.
- Agriculture and livestock : Methane, a much more potent gas than CO₂ in terms of heat retention, is produced in large quantities in the digestion of livestock and in the decomposition of organic matter in rice paddies or landfills.
- Use of industrial products : Some fluorinated gases, such as CFCs or HFCs, are used in refrigeration, aerosols or industrial processes, and although they are present in smaller quantities, they are very effective at trapping heat.
3. Population growth and consumption
As the world's population grows, so does the demand for energy, food and goods.
This increases activities that generate GHGs, such as transportation, industrial production and intensive agriculture.
4. Waste and waste management
Garbage dumps produce methane as organic waste decomposes.
In addition, inadequate wastewater treatment also contributes to emissions.
10 Effects of the greenhouse effect
1. Rising global temperatures
The increase in greenhouse gases is raising the Earth's average temperature, leading to more frequent and intense heat waves. This seriously affects human health, especially in regions where extreme temperatures exceed 40°C.
In addition, global warming alters entire ecosystems, disrupting natural cycles such as migration and plant flowering. These changes also impact agricultural production and global biodiversity.
2. Melting of glaciers and ice caps
Global warming is rapidly melting glaciers and ice caps, posing a serious threat to polar ecosystems. Species such as polar bears and penguins are losing their natural habitat, putting them at risk of extinction.
Globally, this melting ice is raising sea levels, putting coastal cities and small islands at risk. It is also disrupting key ocean currents, impacting weather patterns.
3. Rising sea levels
Rising sea levels are one of the most visible consequences of the intensified greenhouse effect. Many coastal communities face frequent flooding, losing habitable land and resources.
In addition, saltwater intrusion into aquifers contaminates freshwater sources, affecting agriculture and human consumption. This phenomenon is displacing thousands of people, turning them into climate refugees.
4. Extreme weather events
Climate change is intensifying hurricanes, storms and droughts. Hurricanes like Katrina and Dorian have shown how these phenomena can be more destructive due to rising ocean temperatures.
On the other hand, prolonged droughts affect food production, leaving millions in food insecurity. Torrential rains, on the other hand, cause landslides and floods that destroy infrastructure and crops.
5. Loss of biodiversity
The greenhouse effect is altering natural habitats at a rate that many species cannot sustain. Forests, coral reefs and wetlands are disappearing, leading to the extinction of animals and plants essential to ecosystems.
In addition, changes in climate cycles make it difficult for species to migrate or adapt to new environments. This leads to imbalances in food chains and the loss of ecosystem services.
6. Ocean acidification
Oceans absorb some of the atmospheric CO₂, which changes their chemistry and makes them more acidic. This phenomenon affects marine species such as molluscs, corals and crustaceans, whose shells are weakened by acidity.
The loss of marine biodiversity not only affects ecosystems, but also millions of people who depend on fishing as a source of food and employment.
7. Impacts on agriculture and food security
Climate change is destabilizing agricultural production. Droughts, floods and extreme temperatures affect the growth of staple crops such as wheat, corn and rice.
In addition, changes in climate cycles make it difficult to plan planting and harvesting, reducing food availability and increasing prices. This exacerbates food insecurity in vulnerable communities.
8. Human health problems
Extreme temperatures are increasing cases of heat stroke and respiratory illnesses. In addition, warmer climates facilitate the spread of mosquito-borne diseases such as dengue and malaria.
Air pollution, caused by burning fossil fuels, also worsens conditions such as asthma and other lung diseases, especially affecting children and the elderly.
9. Movement of people
Rising sea levels, droughts and extreme events are forcing entire communities to flee their homes. These people, known as climate refugees, face uncertainty and lack of resources.
Climate-induced mass migration creates social and economic tensions in destinations. If not properly managed, this phenomenon could intensify geopolitical conflicts in the future.
10. Impact on the global economy
Climate change causes massive economic losses due to natural disasters, damage to infrastructure and reduction in agricultural production. The most affected sectors are tourism, fishing and agriculture.
Governments must also allocate huge resources to respond to disasters and rebuild affected areas. This puts a strain on economies, especially in developing countries that have less capacity to adapt.
Why is the greenhouse effect a problem?
The greenhouse effect is not a problem for life on Earth. In fact, it is essential to retain solar heat and prevent it from freezing. The problem arises when this natural effect is enhanced by human action.
By increasing this effect through other types of gases, the Earth's temperature rises and negatively affects the species that live on it. For example, carbon dioxide or nitrogen oxide.
This is what is called global warming and one of the causes of climate change.
Burning fossil fuels or setting a forest on fire causes carbon dioxide to be emitted. If the concentration of CO2 in the atmosphere increases, the greenhouse effect increases.
Popular opinion began to worry about this at the end of the 20th century.
Consequences of global warming
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Desertification and droughts, which cause hunger pandemics.
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Deforestation, which further increases the change.
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Melting of Antarctic ice caps, causing sea level to rise. Rising ocean levels would cause coastal cities to flood.
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Destruction of ecosystems.
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It would alter climatic regions and ocean currents, with potentially significant consequences for human activities.
Relationship with energy
The greenhouse effect is closely related to the use of energy, especially that generated from fossil fuels such as coal, oil and natural gas.
These energy sources are responsible for the majority of carbon dioxide (CO₂) emissions, one of the main greenhouse gases. Burning these fuels to generate electricity, move vehicles or power industries releases large quantities of gases that accumulate in the atmosphere, intensifying global warming.
Furthermore, energy consumption in human activities such as transport, heating and cooling is also linked to increased emissions of methane (CH₄) and nitrous oxide (N₂O), which are generated in processes such as natural gas extraction and the use of fertilizers. On the other hand, renewable sources, such as solar, wind and hydroelectric energy, represent a key alternative to reduce these emissions, since they produce electricity without emitting greenhouse gases. However, their implementation still faces economic, technological and political barriers in many regions of the world.
Finally, increasing energy demand due to population and economic growth exacerbates the problem. As more people gain access to electricity and transportation, dependence on fossil fuels remains high in many countries. This highlights the need for an energy transition towards more sustainable systems, where energy efficiency and the use of clean technologies are essential to mitigate the effects of climate change and curb the impact of the intensified greenhouse effect.
Greenhouse gases
Greenhouse gases are responsible for this effect on the atmosphere. We list them in order of importance.
- Water vapor (H 2 O)
- Carbon dioxide (CO 2 )
- Ozone (O 3 )
- Other gases in smaller proportions.
- Methane (CH 4 )
- Nitrous oxide ( N2O )
- Sulfur hexafluoride (SF 6 )
- CFC
One of the most relevant moments was during the industrial revolution. During this process, the consumption of fossil fuels increased exponentially. Consequently, the emission of gases also increased in the same proportion.
The Kyoto Protocol: agreements reached
The Kyoto Protocol is an international agreement that attempts to limit greenhouse gas emissions globally. The protocol arises from international concern about global warming, which could lead to an increase in uncontrolled emissions of these gases.
The agreements that were carried out in the Kyoto Protocol in 1997 were:
- The signatory industrialized countries have committed to reducing greenhouse gas emissions by 5% between 2008 and 2012 compared to 1990.
- Rich countries must reduce their greenhouse gas emissions by 25% to 40% by 2020 compared to 1990.
- The long-term negotiations stipulate that the temperature increase must be below two degrees compared to pre-industrial levels. This target will be revised to not exceed 1.5 degrees.
- Adaptation of less industrialized countries to cope with disasters related to climate change.
- Industrialized countries should promote strategies to reduce carbon emissions and developing countries should limit emissions with appropriate national plans and actions.
- Action plans must be subject to an international control and verification system every two years, although they must be done in a way that is non-instructive, non-punitive and respectful.
- Industrialized countries must provide $30 billion in aid over three years, by 2012, and mobilize resources of up to $100 billion annually by 2020.
- The aid will be channelled through a fund with 24 members, 12 of which will come from rich countries and others.