Global warming has been happening all around us and has been for hundreds of years. We need to fix it soon as it will have a huge adverse impact on our future generations.
Learning objectives
In this lesson, we will learn about
- What is global warming?
- What are the causes of global warming?
- Man-made versus natural causes of global warming
- What are the effects of global warming?
What is global warming?
The Earth is heating up. Both land and oceans are warmer now than in 1880 when record-keeping began. Temperatures are still rising. This rise in temperature of the Earth is global warming.
Global warming is defined as the gradual increase in the average temperature of the Earth’s atmosphere and oceans since the preindustrial age.
Since 1880, the earth’s average temperature has risen about 1 degree Celsius or 1.9 degrees Fahrenheit.
Causes of global warming
The major cause of global warming is the greenhouse effect. When carbon dioxide (CO2) and other air pollutants and greenhouse gases collect in the atmosphere and absorb solar radiation that has bounced off the earth’s surface. Normally, this solar radiation would escape into space but these pollutants trap the heat and reflect it back, causing the Earth to get hotter. This phenomenon is known as the greenhouse effect.
Following are the major causes of global warming
Man-made causes of global warming
- Deforestation – Plants take in carbon dioxide and release oxygen into the environment. Due to residential and commercial purposes, trees are cut down. This has led to an imbalance in the environment thereby increasing the carbon dioxide levels in the atmosphere.
- Use of vehicles – Vehicles burn fossil fuels which emit a large amount of carbon dioxide and other toxins into the atmosphere resulting in a rise in temperature.
- Chlorofluorocarbon (CFCs) – They are a group of compounds that contain the elements chlorine, fluorine, and carbon. At room temperatures, they are usually colorless gases or liquids which evaporate easily. They are widely used in air conditioners and refrigerators. The CFCs had led to ozone layer depletion making way for ultraviolet rays, thereby increasing the temperature of the earth.
- Industrial development – The harmful emissions from the factories add to the increasing temperature of the earth.
- Agriculture – Various farming activities produce carbon dioxide and methane gas. These add to the greenhouse gases in the atmosphere and increase the temperature of the earth.
- Overpopulation – An increase in population means more people breathing. This leads to an increase in the level of carbon dioxide, the primary gas causing global warming, in the atmosphere.
Natural causes of global warming
- Volcanoes – The ash and smoke emitted during volcanic eruptions go out into the atmosphere and affect the climate.
- Water vapor – Water vapor also acts like greenhouse gases. Due to the increase in the earth’s temperature more water gets evaporated from the water bodies and stays in the atmosphere adding to global warming.
- Melting permafrost – Permafrost has environmental gases trapped in it for several years. As the permafrost melts, these environmental gases are released back into the atmosphere, thus increasing the earth’s temperature.
- Forest fires – Forest blazes and forest fires emit a large amount of carbon-containing smoke. These gases are released into the atmosphere and increase the earth’s temperature resulting in global warming.
Effects of global warming
- Rise in temperature – Global warming has led to a rise in the earth’s temperature. This has resulted in an increase in the melting of glaciers which have led to an increase in the sea levels.
- Climate change – Global warming has led to a climatic imbalance with droughts and floods.
- The spread of diseases – The rise in temperature had resulted in patterns of heat and humidity. There is a rise in illnesses such as heat stress, infectious diseases like asthma and allergies, and insect-borne infections such as dengue fever.
- The threat to the ecosystem – Increasing temperatures are stressing both terrestrial and marine species and habitats. Loss of natural habitats is making several plants and animals vulnerable to extinction.
