Climate change is a very significant issue in our society and the world today.
In recent years, most countries of around the world have come to understand the importance of this topic, and the potential problems and challenges that may soon arise as a result of climate change.
In fact, these potential challenges are so serious that they affect the chances of survival of the entire human populace. An important question which may be asked, is;
This article explores the different significant ways climate change occurs. It also discusses these causes of climate change.
The contents of this article include the following, broad categories;
The Causes of Climate Change
As stated at the beginning of this article, the causes of climate change in the world today can easily be grouped into two broad categories.
One of these is the Natural Causes.
The second is the Anthropogenic, or Man-made Causes.
* Natural Causes of Climate Change
Natural Causes of Climate Change are simply those factors which exist in nature, and which contribute to climate change.
The manner by which natural factors may cause climate change, could be either passive or active.
By ‘passive’ here, we mean that these natural factors may cause climate change by contributing to a series of micro effects or chain reactions that affect the climate.
By ‘active’, we refer to natural factors that can affect the climate simply by attacking the environmental components that control climate, such as the oceans, forests, soil, ozone layer, and other parts of the atmosphere.
The natural causes of climate change include the following;
1). Ocean currents and Climate Change
As we have stated earlier, the oceans are among the most significant natural factors that may affect climatic conditions. This means that they are a fundamental, natural component of the climate and its system .
Ocean currents simply refer to currents in the ocean which occur above or below the surface. These currents may function either at the very surface of the ocean, or up to 300 meters deep .
Ocean currents have the ability to move marine waters in a vertical or horizontal direction, and they may be large or relatively small in their scale and effect.
Ocean currents are driven mainly by other natural factors. These include tides, wind, solar energy, differences in water density across space, ocean floor topography, shape or profile pf ocean basins, and rotation of the Earth (or Coriolis Effect) [16; 7].
Differences in water density are known to mainly drive deep ocean currents, while the currents at or close to the surface, are more influenced by other factors like wind and tides.
Also, the deep Ocean currents are slightly different from surface ocean currents in terms of their speed, energy and magnitude.
Density of water is itself controlled by salinity, depth, and temperature, In general, water density increases with increase in salinity, decrease in temperature, and increase in depth .
How Ocean Currents Cause Climate Change
The differences in density of water within the ocean, leads to circulation and mixing. This is because, denser water masses are always sinking or moving downward, while less-dense water masses will move upward under the force of gravity.
These movements which are involved in mixing and circulation, all result in what is known as the Ocean Conveyor Belt . This is a circulatory system formed by the sinking and rising of water masses in the oceans.
The processes by which these water masses sink and rise are simultaneous. Also, the ocean conveyor belt circulation system, is self-sustaining, and consistent as long as the oceans exist.
We can also look at it as a result of the movement of water masses away from, and toward, the equator, as follows;
– Less-dense water masses (which are warmer) rise and move away from the Equator toward the polar regions.
– Dense water masses (which are colder) sink and move toward the Equator
Through these movements, ocean currents circulate or distribute heat energy across the globe.
This affects the climate by controlling the balance in temperature across different regions of the globe.
It also helps to circulate atmospheric gases, which may be dissolved in ocean water. These gases, such as Carbon dioxide (CO2) and Nitrogen, affect the weather and ultimately the climate.
Nutrients and oxygen which are circulated in ocean currents, determine the distribution of living organisms which depend directly or indirectly on these for their survival.
The distribution and population size of living organisms affects the climate.
This is because they influence how natural processes are maintained in the ecosystem.
2). Volcanic Eruption and Climate Change
Volcanic eruptions have been found to affect the climate in different ways. Mainly, they may cause cooling of the Earth’s atmosphere for a relatively short period of time.
This is because volcanic eruptions involve the emission of large volumes of particulate materials. Some of these materials include ash and dust particles. These materials generally block out sunlight and heat energy from the sun, reducing the amount of solar radiation that reaches the Earth’s surface .
After a period of time which is often no more than three months, these ash and dust particles fall to the surface of the Earth under the force of gravity (due to their own weight).
However, sulfur dioxide, which is also usually contained in volcanic ash, can remain in the atmosphere for much longer periods.
Because of their relatively light weight, this gas can stay for over a year in the atmosphere, after the volcanic eruption which produced them has occurred .
Sulfur dioxide may combine with dust particles and water vapor in the atmosphere, forming sulfate aerosols that deflect solar radiation from the Earth Surface.
On the other hand, volcanic eruptions release greenhouse gases that contribute to Ozone layer depletion and Global Warming.
However, the cooling effect of volcanic eruption outweighs its warming effect on the climate .
3). Solar Radiation and Climate Change
Variations in the intensity of solar radiation are known to contribute to climate change.
In fact, the Sun can be viewed as the main source of energy to the Earth’s atmosphere and climate.
While the energy produced by the Sun may appear to be constant, it in fact changes over time .
This leads to changes in the climate. It is believed by some scientists that solar energy has contributed to a significant portion of global warming and climate change.
As earlier said, the Sun serves as the basic source of energy to the Earth and the climatic system.
This implies that changes in solar radiation have played a significant role in climate change.
4). Changes in Earth’s Orbit as one of the Causes of Climate Change
The Earth’s orbit experiences numerous shifts over time. These shifts can lead to climatic changes like ice ages and cooling cycles.
However, these orbital changes occur gradually and can be noticed only over a long period of time. The Earth is currently tilted at 23.5° to the perpendicular plane of its orbit.
Although it typically takes thousands of years to show significant changes, the alteration of the Earth’s orbital path leads to climatic changes.
5). Meteorite Impact as one of the Causes of Climate Change
While cases of meteorite impact are not common, they are known to affect the climate.
Meteorite impact typically raises large clouds of dust into the atmosphere. These dust clouds may form a temporary layer of protection from solar radiation.
However, meteorite impact also typically produces greenhouse gases like methane and carbon dioxide . These gases may later attack the ozone layer, causing increase in climatic temperature around the globe.
* Anthropogenic or Man-made Causes of Climate Change
Human activities are known to be a major cause of climate change on Earth today.
These activities can be collectively referred to as Anthropogenic or Human-induced causes of climate change.
Some of the important, anthropogenic causes of climate change are discussed below;
6). Burning of Fossil Fuels as one of the Causes of Climate Change
Fossil fuels include coal, oil and gas . These materials are composed of mainly hydrogen and carbon, and are formed by the alteration of organic remains which have been buried for millions of years.
Fossil fuels are used extensively as a source of energy for different purposes. However, they have been found to negatively impact the climate.
How Fossil Fuels Contribute to Climate Change
When we use fossil fuels to produce energy (through a process of combustion), they release greenhouse gases into the atmosphere.
These gases include methane, carbon dioxide, sulfur dioxide, nitrogen oxide and water vapor.
The gases attack and deplete the ozone layer whose sole function is to protect the earth from harmful solar radiation. It therefore causes an increase in the atmospheric temperature near the Earth’s surface.
Over the years, the level of Global carbon emissions as a result of the burning of fossil fuels, has risen notably.
There has been an increase by approximately 90%, of the emissions of CO2 from fossil fuels, worldwide, since the year 1970. This increase is significantly driven by industrial processes that use these fossil fuels as a source of energy.
It was found by the Intergovernmental Panel on Climate Change (IPCC) has found that fossil fuel gaseous emissions are the most notable cause of global warming. They account for 85-89% of CO2 emissions globally.
7). Deforestation as one of the Causes of Climate Change
It is well-known how plants take in carbon dioxide (CO2) and release Oxygen (O2) during the process of photosynthesis.
This process is very important to ensure that the amount of CO2 in the atmosphere is kept at its minimum.
Deforestation refers to the cutting-down of trees. These treed may thereafter be used for furniture, firewood, manufacturing, or left to rot away.
Recall that carbon dioxide is one of the greenhouse gases. Larger amounts of this gas in the atmosphere increases the risk and rate of ozone layer depletion .
Also, when trees are felled (cut down) and either used ad fuel or left to rot, they release their stored carbon dioxide into the atmosphere.
Deforestation alone, accounts for up to 10 percent of greenhouse gas emissions in the world today.
Currently, the area of land on Earth which is covered by forests is about 29%. However, this proportion is likely to reduce in the coming years.
Up to 520,000 square miles of forest land has been lost since 1990, and nearly 50 percent of forest area before the industrial revolution has been ‘reclaimed’ and converted to human habitation or industrial land area.
The problem of deforestation is very pronounced in developing areas of the world, where forest timber is still relied upon as a fuel, by a significant proportion of the rural population.
For example, Nigeria in West Africa experienced a loss of about 15% of her forest land between 2000 and 2020. Most of the former forestland was converted to agricultural land for subsistence farming.
This further worsens the condition with respect to climate change, since agricultural practices have been shown to be a major source of nitrous greenhouse gases.
Annually across the globe, approximately 10-20 million hectares of forest land is lost to logging and timber trade activities.
Sadly, deforestation is a widespread practice in our modern society.
This is because of growth in the human population which results in more need for land and raw materials.
Places that were once forests are now being cleared and bulldozed for human habitation.
Agriculture accounts for a significant proportion of the cause of climate change.
This proportion is the equivalent of 8-14 percent of the overall greenhouse gas emissions each year.
In general, there are a few main aspects of agriculture that can lead to climate change. They are discussed as follows;
8(a). Livestock Farming
Livestock farming also contributes immensely to climate change. This is because there are several greenhouse gases which are produced in the process of rearing livestock.
Examples of such gases are Carbon Dioxide (CO2), Methane (CH4), and Nitrogen Oxide (N2O) .
Methane is both produced in large quantities while food is being digested by cattle. This process of called Enteric Fermentation .
Methane and Carbon Dioxide (CO2) are both produced in the process of manure storage.
8(b). Fertilizer Usage
The use of Nitrogen-based fertilizer across the globe has increased, due to pressure on food supplies by the growing human population .
These fertilizers affect the climate negatively, by increasing the nitrogenous content of the soil.
Soil nitrogen is later released as nitrous oxide (N2O) into the atmosphere, as a result of the activities of microbes.
Nitrogen-based fertilizers and nitrous oxide emissions are significant to global warming and the change in the climate.
By estimate, fertilizers are responsible for 2.5% (approx.3.0%) of the overall volume greenhouse gas emissions around the world. This equals to roughly 1 billion metric tons equivalent of CO2 in 2021.
Nitrogen-based fertilizers produce greenhouse gas emissions, from the actions of microbes in the soil.
These microbes, including examples like Achronobacter and Pseudomonas, are often referred to as Denitrifying Bacteria (or Denitrifying Microbes).
They break down the complex nitrogen compounds in the fertilizer, and produce gaseous nitrates (N2O), which are released into the atmosphere.
Nitrous Oxides are the third most active greenhouse gases, after Methane and Carbon dioxide.
Up to 80 percent of nitrous oxides released due to human activities, are agriculturally produced.
The rate at which these gases are produced, has been significantly increased by the use of nitrogen-based fertilizers.
8(c). Bush Burning
Especially in regions where mechanized agriculture is not widely practiced, bush burning is usually applied for clearing farmlands before and/or after planting and harvest.
Bush burning produces carbon dioxide (CO2) which is a greenhouse gas.
9). Aerosol Release as one of the Causes of Climate Change
Most aerosol products are known to cause ozone layer depletion, which is one of the processes involved in climate change.
These aerosols often contain chlorofluorocarbons, that attack the ozone layer when released into the atmosphere. They may be found in sprays like insecticides and paint.
10). Land-use and Climate Change
Land use is a very significant factor with respect to climate change.
A land area can be typically used for any of the following purposes;
* Habitation, Dwelling or Settlement (Urban, Semi-Urban, Rural)
* Agriculture (Livestock, Crop)
* Industry (Manufacturing, Energy, Processing)
* Forestry (Vegetation and/or Wildlife Conservation)
For any of these purposes, the consequences on the environment are often unique.
In the case of land used for habitation or settlement purpose, urban dwellings are more likely to influence climate change than rural areas.
This is because the use of fossil fuels, aerosol products and other materials that release ozone depleting substances (ODS) into the atmosphere, is generally more pronounced in urban regions .
In rural areas, the burning of biomass as a fuel can lead to elevated levels of CO2 in the atmosphere, which can contribute to global warming.
Biomass here refers to timber and other materials gotten from vegetation and/or animals, which can serve as firewood or other forms of fuel for domestic purposes.
Land-use for Agriculture may be either by crop or livestock farming.
In crop production, practices like bush burning and fertilizer usage can release greenhouse gases into the atmosphere.
Also, other practices like crop rotation can lead to changes in the amount of greenhouse gases. Crop production may reduce greenhouse gases and global warming, when the plants absorb carbon dioxide and use nitrogen in the course of their respiration and growth.
Industrial uses of land can also lead to climate change.
Most industrial processes are known to emit greenhouse gases directly into the atmosphere. Some manufacturing industries like cement production, steel and iron manufacturing, eject large quantities of carbon dioxide, sulfur dioxide and methane among others.
Other manufacturing industries like paper, textile, and chemicals require large amounts of energy. This implies that fossil fuels are used extensively in such industries, and it leads to greenhouse emissions, ozone layer depletion, global warming, and ultimately; Climate Change.
Industrial Process – Fossil Fuel Combustion – Greenhouse Gas Emission – Global Warming- Climate Change
Energy industries include Electricity Generation and Heat Production companies. These companies use fossil fuels extensively.
Others like oil and gas industries produce enormous amounts of carbon dioxide, methane, nitrous oxides and sulfur dioxide.
This usually occurs during drilling (methane or natural gas is released), gad flaring, transport and processing (by fractional distillation) of hydrocarbons.
Mining of other energy-producing materials like coal also results in greenhouse gas emissions.
This is usually due to large volumes of methane in coal mines and the use of machinery that require other fossil fuels to operate.
The amount of methane in coal mines may be so enormous that it could lead to blowouts during mining, causing loss of lives and equipment.
These greenhouse gases released by industries all contribute to global warming and climate change.
Commerce is a very important factor of the society. It requires the use of fossil fuels, especially for transportation, and powering of electrical equipment and utilities.
E-commerce platforms like Amazon are large scale operators. These companies emit large volumes of methane, sulfur dioxide, carbon dioxide and other greenhouse gases in the process of transporting, distributing and delivering goods and services.
Forestry affects climate change in a generally positive way. This is because trees and other forms of vegetation, use carbon dioxide (a greenhouse gas) in the atmosphere, and release oxygen. They also help to balance the equilibrium of energy transfer in the ecosystem.
However, changes in the type of vegetation in forest land over time can cause minor changes in the climate. This is because different types of vegetation consume carbon dioxide and emit oxygen in different ways.
In general, vegetation and forestry land-use affect the climate in a positive way, by consuming CO2, releasing Oxygen and storing away carbon and nitrogen.
Conclusion: Climate Change Causes
Climate change can be caused by natural or man-made processes and factors.
The natural causes of climate change include volcanic eruption, Earth orbital variation, meteoric impact, and solar radiation.
Man-made or anthropogenic causes of climate change include burning of fossil fuels, land-use, deforestation and agricultural practices.
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