CBSE Class 8 Answered
The greenhouse effect is a process in which greenhouse gases, like carbon dioxide in the Earth's atmosphere, cause thermal radiation emitted by the Earth's surface to be reflected back down, therefore causing the climate to warm.
About 30 percent of the sunlight falling on Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet's surface and is reflected upward again as a type of slow-moving energy called infrared radiation. The heat caused by infrared radiation is absorbed by greenhouse gases such as water vapor, carbon dioxide, ozone, and methane, which slows its escape from the atmosphere. The greenhouse gases regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet. This phenomenon is the greenhouse effect.
Causes: The greenhouse effect is accelerated due to the following human activities:Burning natural gas, coal, and oil for automobile engines-raises the level of carbon dioxide in the atmosphere. Certain farming practices and land-use changes increase the levels of methane and nitrous oxide. Several industrial gases emitted by many factories contribute significantly to the enhanced greenhouse effect and "global warming" Deforestation also contributes to global warming. Population growth is another factor in global warming because as more people use fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the atmosphere.
Effects:Global warming is a huge problem caused by increased greenhouse effect. Scientists agree that even a small increase in the global temperature would lead to significant climate and weather changes, affecting cloud cover, precipitation, wind patterns, the frequency and severity of storms, and the duration of seasons.