The earth’s atmosphere contains several chemical substances that act as greenhouse gases. Most of the visible light from the Sun passes through the atmosphere and reaches the Earth’s surface. When the Earth’s surface is heated by sunlight, a portion of the energy is radiated back into space as infrared radiation. Unlike visible light, this radiation tends to be absorbed by greenhouse gases in the atmosphere, increasing the temperature. The heated atmosphere reflects infrared radiation to the Earth’s surface. Despite its name, the greenhouse effect is not the same as the warming that occurs in a greenhouse, where glass panes reflect visible light but trap heated air inside the structure.
Earth’s average surface temperature would be just approximately 18 °C without the greenhouse effect’s heating. On Venus, the extremely high carbon dioxide content in the atmosphere generates an intense greenhouse effect, resulting in surface temperatures of up to 450 degrees Celsius.
The earth’s atmosphere contains several chemical substances that behave as greenhouse gases. Some of the sunlight that touches the earth’s surface is reflected into space as infrared radiation (heat). Greenhouse gases absorb this infrared radiation and retain the heat in the atmosphere, resulting in global warming and climate change.
NATURAL GREENHOUSE EFFECT
The oceans and land naturally release greenhouse gases on a yearly cycle.
CO2 is absorbed into plants as they develop and sprout leaves, while CO2 is released when the vegetation decomposes. GHG is produced by volcanoes. CO2 is exhaled by animals as they breathe. Methane may be found in manure and wetlands.
ENHANCED GREENHOUSE EFFECT
Humans contribute to global warming by releasing more greenhouse gases into the atmosphere. Burning fossil fuels (such as coal, gasoline, and natural gas) produces most of the extra greenhouse gases, which are responsible for disrupting the natural balance of the Greenhouse Effect.
As more greenhouse gases are created, they build up in the atmosphere, where they absorb long-wave counter-radiation. Infrared (i.e., infrared) More radiation is reflected on Earth, resulting in increased global warming.
TYPES OF GREENHOUSE GASES
International estimates of greenhouse gas emissions include many important greenhouse gases produced by human activity:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Industrial gases include –
- Hydrofluorocarbons (HFCs)
- Perfluorocarbons (PFCs)
- Sulfur hexafluoride (SF6)
- Nitrogen trifluoride (NF3)
IMPACT OF GREENHOUSE GASES ON OZONE LAYER
The ozone layer protects the Earth’s surface from damaging UV rays. The ozone layer is found in the lower stratosphere of the Earth’s atmosphere (15-35 km above the surface) and has quite high ozone concentrations (O3). Ozone layer depletion is the gradual reduction of the earth’s ozone layer in the upper atmosphere.
The existence of excess greenhouse gases, particularly human-made chemicals such as halocarbon refrigerants, solvents, propellants, and foam-blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons), is the primary cause of ozone depletion.
The ozone layer’s depletion has negative impacts on human health, wildlife, the environment, and marine life. According to studies, an increase in UV-B rays increases the risk of skin cancer, has a big role in the development of malignant melanoma, sunburns, rapid ageing, eye cataracts, blindness, and the weekend immune system. In animals, direct exposure to UV light causes skin and eye cancer. UV-B rays hurt plants and crops. It may result in little plant growth, reduced leaf size, blooming, and photosynthesis in plants, as well as lower-quality human harvests. Reduced plant productivity influences soil erosion and the carbon cycle. UV-B radiation has a significant impact on planktons and zooplankton. If plankton levels decline, it will have far-reaching implications for all aquatic animals in the food chain.
IMPACT OF GREENHOUSE GASES ON THE CLIMATE
Climate change as a result of the ‘increased greenhouse effect’ caused by human activity is regarded as a serious worldwide environmental risk to humanity. Human activities have resulted in gradually growing amounts of greenhouse gases—carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons—in the atmosphere since industrialization, raising concerns about the ‘enhanced greenhouse effect.’ Carbon dioxide accounts for around two-thirds of the ‘increased greenhouse effect.’
According to historical records, the Earth has warmed by 0.5°C and the global sea level has risen by 15 cm since the beginning of the century. If no efforts are taken to reduce greenhouse gas emissions, climate models project further warming of 0.3°C every decade. This rate of warming is faster than it has been in the last 10,000 years, and it is expected to cause global changes in agricultural patterns, precipitation, water resources, sea-level rise and coastal inundation, and the occurrence of more frequent and intense extreme events such as droughts and hurricanes. Some of these developments will be particularly harmful to African countries. Climate change forecasts at the regional level, as well as the amount and timing of such changes, remain uncertain.
CONCLUSION
As it is, life on Earth depends on the natural greenhouse effect of the atmosphere. This is caused by a mechanism in which the atmosphere of a planet traps solar energy and heats the planet’s surface. Climate change is speeding up, and habitat fragmentation caused by human activities is one of the selection forces shaping a new Earth’s surface. One of the mechanisms driving climate change is greenhouse gases. Climate change is a multidimensional and simultaneous shift in the duration, frequency, and severity of characteristics such as temperature and precipitation, which affects the seasons and life on Earth. Plant species with more adaptive plasticity will be better able to cope with variations in the frequency of extreme weather events in this scenario.