Climate change refers to long-term changes in weather patterns and temperature. These changes might be generated by natural sources, such as solar cycle oscillations. However, human activities have been the dominant source of climate change since the 1800s, owing mostly to the usage of fossil fuels such as coal, oil, and gas.
In this article, we will look into the various causes of climate change and its impacts.
Causes of climate change
Greenhouse effect and greenhouse gases
Certain gases in the Earth’s atmosphere retain heat and prevent it from escaping into space. These gases are known as “greenhouse gases”. Both human and natural sources emit greenhouse gases. Carbon dioxide, methane, and nitrous oxide are all naturally occurring greenhouse gases in the environment. Others, like chlorofluorocarbons (CFCs), are created by humans. These gases serve as a warming blanket around the Earth, and this is when the “greenhouse effect” occurs.
When the sun’s short-wave radiations reach Earth, most of them pass right through and touch the surface. Most of this energy is absorbed by the surface, which emits longer-wavelength infrared light. Instead of being sent directly into space, greenhouse gases absorb part of this infrared light. The atmosphere then emits the absorbed light rays in all directions, sending some of them back to the surface, thus, causing the planet to heat up.
The greenhouse effect is essential for survival as the planet would be about 30 degrees cooler if it did not occur. However, since the industrial revolution, human activities have led to an increase in the amount of greenhouse gases in the atmosphere, therefore, heating up the planet at a faster rate than ever before.
Natural causes of climate change
The climate can vary between warming and cooling due to various natural phenomena. Among these are:
Milankovitch Cycles:
The route of the Earth and the tilt of its axis might shift somewhat as it revolves around the Sun. These fluctuations, known as Milankovitch cycles, have an impact on the quantity of sunlight that falls on Earth. As a result, the temperature of the Earth may change, but across tens or hundreds of thousands of years.
El Nino Southern Oscillation (ENSO):
ENSO is a pattern of shifting Pacific Ocean water temperatures. The global temperature rises during an ‘El Nino‘ year (warming of the central and eastern Pacific ocean’s surface) and falls during a ‘La Nina‘ year (cooling of the surface of the Pacific ocean). These trends can have a short-term impact on global temperature.
Volcanic eruptions
Volcanoes have an unfavourable impact on our climate. Eruptions emit aerosol particles that cool the Earth, but they also emit carbon dioxide, which heats it. However, volcanoes emit 50 times less carbon dioxide than people, indicating that they are not the primary source of global warming.
Solar irradiance
Changing energy from the Sun has influenced Earth’s temperature in the past. However, we have not observed anything significant enough to cause a shift in our climate.Â
Human causes of climate change
By releasing carbon dioxide and other greenhouse gases into the atmosphere, humans contribute to climate change. In fact, there is more carbon dioxide in the atmosphere today than there has been in at least 2 million years. We emit greenhouse gases in a variety of ways, including:
Use of fossil fuelsÂ
Carbon dioxide has been ‘locked up’ in the Earth for thousands of years in fossil fuels such as oil, gas, and coal. When we burn them, we release the carbon dioxide that has been stored in the soil into the atmosphere.Â
Deforestation
Carbon is stored in forests and plants. When they are damaged or fully destroyed, for example, by fire, this stored carbon is released back into the atmosphere as carbon dioxide, which contributes to climate change. According to the Intergovernmental Panel on Climate Change, deforestation contributes to 10% of the carbon dioxide emissions created by human activities. However, if tropical peatland emissions are included, this percentage jumps to 15%.
Agriculture
Planting crops and raising livestock emits a variety of greenhouse gases into the atmosphere. Animals, for example, create methane, which is 30 times more strong as a greenhouse gas than carbon dioxide. Nitrous oxide, which is used in fertilisers, is ten times more toxic and over 300 times stronger than carbon dioxide.
Cement production
At high temperatures, calcination of limestone (CaCO3) produces lime (CaO), and carbon dioxide(CO2). The reaction is as follows:
The reaction described above causes around half of the emissions from cement. One of the primary reasons cement emissions are difficult to reduce is because of the carbon dioxide produced by the aforementioned chemical reaction. Therefore, simply changing fuel or boosting efficiency will not reduce these emissions.
Another 40% of cement emissions are caused by the use of fossil fuels to heat kilns to high temperatures required for the calcination process. The remaining 10% of emissions come from fuel needed for the extraction and transportation of raw materials.
Are humans responsible for climate change?
Thus, there is irrefutable evidence that humans are the leading cause of climate change. Natural climatic cycles may modify Earth’s temperature, but the changes we’re experiencing are on a scale and at a rate that natural cycles cannot explain. Moreover, longer-term changes like Milankovitch cycles and solar irradiance take thousands of years to cause any sort of visible change. Thus, human activities, such as burning fossil fuels and changing how we use the land, are the leading cause of climate change.
Final thoughts
Climate change is one of the greatest problems humans are facing today. Not only does it adversely affect the environment, but it also greatly impacts human life and health. Therefore, it is essential to take appropriate steps to control the release of greenhouse gases. Although this might seem difficult, if all of us try to individually change our actions, then we might succeed in saving our planet. The following video shows some actions we can take to help the Earth.
To learn more about climate change visit Podium School.
