Causes of Global Warming

Causes of Global Warming

The phenomenon of global warming, also known as the greenhouse effect, refers to the retention of solar energy in the Earth’s atmosphere in the form of heat. This process primarily occurs on the Earth’s surface and in the troposphere, which is the lowest layer of the atmosphere. It is driven by an increased concentration of certain gases, such as carbon dioxide (CO2), water vapor, methane (CH4), and other greenhouse gases. Among these, water vapor has the most significant impact on this phenomenon. These gases are characterized by their ability to transmit most wavelengths of solar radiation, allowing sunlight to reach the Earth’s surface. However, they are relatively opaque to infrared radiation, which results in heat being absorbed by these gases and then re-emitted, making it difficult for the heat to escape back into space.

For more information about greenhouse gases, you may refer to the article on greenhouse gases.

Sources of Greenhouse Gas Emissions

Greenhouse gases or greenhouse gas emissions occur due to the accumulation of specific gases in the atmosphere, such as carbon dioxide, nitrogen oxides, methane, and fluorinated gases including chlorofluorocarbons (CFCs). While some of these gases are produced naturally in the atmosphere, human activities have significantly increased their concentrations, leading to global warming. The following outlines the primary causes:

Human Activity

Several human activities contribute to global warming, including the following:

Burning Fossil Fuels

The Industrial Revolution, which began in the mid-18th century, led to a dramatic rise in atmospheric carbon dioxide levels from 280 parts per million (ppm) to 387 ppm. This increase is primarily due to the heightened use and combustion of fossil fuels, resulting in an annual increase of 2-3 ppm. By the end of the 21st century, levels are expected to rise further to between 535 and 983 ppm. Consequently, the projected rise in greenhouse gas concentrations in the atmosphere is expected to increase the Earth’s temperature by 1.4° to 5.6° Celsius by the year 2100.

Deforestation

Land utilization methods have changed significantly in recent years, particularly with the removal of forests, especially in tropical regions, to make way for alternative investments. This deforestation contributes to approximately one-third of carbon dioxide emissions in the atmosphere, thereby exacerbating global warming.

Agricultural Activities

Agricultural practices, including the use of fertilizers, rice cultivation, and specific irrigation methods, lead to increased concentrations of methane in the atmosphere. Additionally, the excessive use of fertilizers raises nitrogen oxide (N2O) levels, while deforestation alters the Earth’s albedo, affecting the amount of solar radiation absorbed and reflected by the Earth’s surface.

Livestock Farming

Livestock farming is a significant contributor to global warming, accounting for roughly 18% of global greenhouse gas emissions according to a UN report. The need for grazing land has led to extensive deforestation, particularly in the Amazon rainforest, where about 70% of deforestation is attributed to cattle ranching. Furthermore, methane released from livestock further increases greenhouse gas concentrations, intensifying global warming.

Cement Manufacturing

The cement manufacturing process contributes to carbon dioxide emissions through the heating of calcium carbonate, resulting in the release of carbon dioxide and lime. Additionally, burning fossil fuels needed to produce the required heat also contributes to increased carbon dioxide emissions. Human contributions from cement production represent approximately 5% of total carbon dioxide emissions, while the rest arises from fossil fuel combustion and associated chemical processes, with around 900 kg of CO2 emitted for every 1,000 kg of cement produced.

Industrial Waste and Landfills

Industrial facilities and operations release a variety of harmful gases into the atmosphere, further aggravating global warming. Landfills also contribute to the emission of methane and carbon dioxide, significantly increasing the effects of greenhouse gases.

Population Growth

The world’s population continues to grow annually, leading to increased demand for food, shelter, clothing, and various industrial products. This surge drives the establishment of more factories and industrial activities, resulting in higher emissions of harmful gases in the atmosphere and magnifying the greenhouse effect. Additionally, the growing population leads to increased fossil fuel consumption, significantly exacerbating global warming.

Natural Causes

Several natural factors also contribute to the elevated levels of greenhouse gases in the atmosphere. Historically, the natural contribution of greenhouse gases was relatively balanced, but conditions have changed over time. The following are some of these natural factors:

• Termites contribute to methane emissions through their digestive processes.
• Wild ruminants and certain herbivorous animals increase methane emissions.
• Wildfires release various harmful gases, including carbon monoxide, methane, carbon dioxide, nitrous oxide, and nitrogen oxides.
• Wetland ecosystems contribute to methane emissions.
• Terrestrial ecosystems, such as grasslands, forests, and savannas, emit nitrous oxide.
• Freshwater bodies, including lakes, streams, rivers, and wetlands, emit greenhouse gases like methane, nitrous oxide, and carbon dioxide.
• Volcanic activity.
• The natural decomposition of organic matter from animals and plants.
• The melting of ice caps and glaciers.

For further information on global warming, please refer to the article on what global warming is.

Video on the Causes of Global Warming

To gain more insights into the causes of global warming, please watch the following video.