Question: What is the Greenhouse Effect?

Answer: Definition
The overall process by which short-wavelength light rays from the sun penetrate the atmospheric layers to heat the Earth’s surface, and subsequently, long-wavelength infrared (IR) rays emitted from the surface are trapped by certain atmospheric gases, causing the Earth’s overall temperature to rise above normal levels, is called the Greenhouse Effect. In this process, the lower layer of the atmosphere acts like a greenhouse.

Question: Explain the mechanism and process of the Greenhouse Effect.

Answer: The greenhouse effect primarily occurs in several steps:

• Arrival of Solar Radiation: The Sun is the primary source of Earth’s heat and energy. Short-wavelength rays from the Sun (e.g., Near-UV, Visible light, Near-IR, etc.) penetrate the atmospheric gas layers and easily reach the Earth’s surface. Greenhouse gases in the atmosphere do not obstruct these incoming light rays.
• Radiation of Heat from the Surface: The Earth does not absorb all of the sunlight it receives. After the surface warms up, it re-radiates or releases the excess energy back toward space as long-wavelength Infrared Rays.
• Trapping (Absorption) of Heat: Not all of this long-wavelength infrared radiation emitted from the Earth’s surface can escape into space. Carbon dioxide (CO₂), water vapor (H₂O vapor), and other greenhouse gases in the lower atmosphere absorb this emitted heat or IR radiation.
• Heat Retention and Temperature Rise: This absorbed heat does not escape into space but remains trapped in the atmosphere and is reflected back toward the Earth’s surface. As a result, the heat-retention capacity of the atmosphere gradually increases, causing the Earth’s average temperature to rise.

Question: Explain the global response/impact of the Greenhouse Effect.

Answer: Two types of responses to the greenhouse effect are observed in the current world: (a) Adverse Reactions and (b) Favorable Reactions.

(a) Adverse Reactions

Environmental degradation is a major problem in the modern world. Due to human negligence, a toxic atmosphere is being created every day, pushing current and future generations into a silent poisoning. The major adverse effects of the greenhouse effect are discussed below:

1. Rise in Earth’s Surface Temperature: It allows harmful and ordinary light rays from the Sun to reach Earth, but prevents long-wavelength heat radiated from the surface from escaping into space. As the amount of these greenhouse gases increases in the atmosphere, the intensity of Global Warming will also increase.
– Historical Record: Due to the greenhouse effect, the Earth’s temperature has increased by 0.3° – 0.6°C over the last 100 years.
– Future Forecast: If this warming trend continues at the current rate, the Earth’s temperature will rise by 1.4°C – 4.5°C by 2030, and could reach up to 6°C by 2050.

2. Sea Level Rise and Geographical Disaster:
– Cause of Sea Level Rise: Temperature rise will cause thermal expansion of ocean water. Additionally, the melting of glaciers and polar ice will contribute to sea-level rise.
– Important Reports and Global Damage: According to a report by the Worldwatch Institute, the climate change resulting from the greenhouse effect will put three percent of the Earth’s area at risk, including valuable agricultural land. Furthermore, about one billion people will become homeless. According to researchers at the National Academy of Sciences (USA), the melting of polar ice could cause sea levels to rise by 50–100 cm by 2087.
– Region-Specific Impacts: Potential loss of coastal regions includes areas in America (Miami and 1900 km of Florida coast), Europe and Asia (Seoul, Beijing, London, Netherlands, and England’s east coast), and the Indian Subcontinent (Maldives, Sri Lanka, India’s Madras, Goa, Nainital, Ganges basin, and parts of Bangladesh).

3. Weather Changes and Natural Disasters: Northeast China will become arid. Conversely, India, Bangladesh, Pakistan, Indochina, Maldives, and Indonesia will become wetter (rain-prone). Australia’s summer has lengthened, with rainfall now occurring from October to March. Natural disasters like the 1988 drought in America and the devastating floods in Bangladesh could recur. Cyclones will strike more frequently with greater intensity.

4. Impact on Water Cycle: By 2030, rising temperatures will accelerate thermal expansion and ice melting. By 2030, the sea level is estimated to rise by 30–40 cm above current levels, submerging many low-lying areas and making the environment hazardous.

5. Impact on Ecosystem: Rising surface temperatures will reduce the biological productivity of the oceans. This will diminish the exchange of nutrients between deep seas and surface waters, disrupting the food chain and endangering existence. Changes in atmospheric conditions will lead to short, humid winters and long, hot summers. Biodiversity will be destroyed, forests will vanish, and humans will lose their habitats.

6. Impact on Human Health: Increased temperatures are likely to cause various diseases, including adverse effects on human skin.

7. Impact on Forests and Food Production: Temperature rise will be a major threat to food production. Wheat-producing countries in the northern latitudes, such as Russia and Canada, will turn into desert regions, and soil fertility will significantly decrease. Additionally, intense forest fires will destroy vast forest areas, eventually turning them into deserts.

(b) Favorable Reactions of the Greenhouse Effect

While the greenhouse effect causes overall harm to the Earth, it will bring some benefits or favorable environments to specific countries:

• Rainfall in Arid Regions: Rainfall will increase in the driest areas of China, India, Africa, Australia, and the Middle East.
• Suitability for Cultivation and Habitation: As ice in polar and cold regions begins to melt, millions of acres of desert or ice-covered land in Siberia (former Soviet Union) and northern Canada will become ice-free, making these vast regions suitable for new cultivation and human habitation.