Question

The greenhouse effect is (a) rise in temperature of the earth (b) rise in pressure on the earth (c) decrease in oxygen content of the earth's atmo-sphere (d) decrease in CO \(_{2}\) content of earth's atmosphere

Short answer

The correct answer is (a) rise in temperature of the earth.

Step-by-step solution

Understanding the Greenhouse Effect

The greenhouse effect is a natural process that warms the Earth's surface. It occurs when the Sun’s energy reaches the Earth’s atmosphere - some of this energy is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. The absorbed energy warms the Earth’s atmosphere and surface, maintaining temperatures that support life. This process can lead to an overall increase in temperature on Earth, which is characteristic of its name.

Analyzing the Options

Let's evaluate each option based on our understanding of the greenhouse effect: (a) Rise in temperature of the earth - This aligns with our understanding, as the greenhouse effect is known to cause a warming of Earth's surface. (b) Rise in pressure on the earth - This is unrelated to the greenhouse effect, which primarily involves temperature changes. (c) Decrease in oxygen content of the earth's atmosphere - The greenhouse effect does not directly affect oxygen levels. (d) Decrease in CO \(_{2}\) content of earth's atmosphere - This is incorrect, as the greenhouse effect is actually linked to increased levels of CO \(_{2}\) and other greenhouse gases.

Selecting the Correct Option

After analyzing all options, (a) 'rise in temperature of the earth' correctly describes the primary effect of the greenhouse effect. It is the process responsible for warming the planet through the accumulation and emission of infrared radiation by greenhouse gases.

Key concepts

Greenhouse Gases

Greenhouse gases play a key role in the greenhouse effect. These gases are responsible for trapping heat in Earth's atmosphere, keeping our planet warm enough to support life. Some common greenhouse gases include carbon dioxide (CO \(_2\)), methane (CH \(_4\)), and water vapor (H \(_2\)O). Each of these gases has different properties and effects.

• Carbon dioxide is released through activities like burning fossil fuels and deforestation.
• Methane is produced through agricultural practices and decomposition in landfills.
• Water vapor amplifies the warming initiated by other gases.

Without greenhouse gases, Earth would be too cold for life, as most heat would escape into space. However, human activities are increasing greenhouse gas concentrations, enhancing the natural greenhouse effect and warming the planet.

Earth's Atmosphere

The Earth's atmosphere is a thin layer of gases surrounding our planet. This vital layer serves many purposes, most importantly providing us with the air we breathe and protecting us from harmful solar radiation. It consists of several layers: troposphere, stratosphere, mesosphere, and thermosphere. Each of these plays a specific role in regulating the Earth's climate.

• The troposphere is where weather occurs and where most greenhouse gases are concentrated.
• The stratosphere contains the ozone layer, which protects us from harmful ultraviolet rays.

The atmosphere's composition has changed over the years due to natural processes and human activities, affecting climate patterns and influencing natural processes crucial to life.

Global Warming

Global warming refers to the long-term increase in Earth's average surface temperature. It's primarily attributed to the buildup of greenhouse gases from human activities, such as the burning of fossil fuels and deforestation. As the concentrations of these gases rise, they trap more heat, leading to a variety of environmental impacts.

• Melting ice caps and glaciers contribute to rising sea levels.
• More frequent and severe weather events, such as hurricanes and droughts.
• Disruption of ecosystems and changes in wildlife populations.

Addressing global warming involves reducing greenhouse gas emissions and finding sustainable ways to manage human activities that contribute to climate change.

Infrared Radiation

Infrared radiation is a type of electromagnetic radiation invisible to the human eye but detectable as heat. It plays a major role in the greenhouse effect. When sunlight reaches Earth's surface, it's absorbed, and then a portion is radiated back into the atmosphere as infrared radiation.

• Greenhouse gases absorb and emit infrared radiation, which warms the atmosphere.
• This re-radiation is essential for maintaining Earth's habitable temperature.

However, excess greenhouse gases lead to more infrared radiation being trapped, thus contributing to global warming. Understanding the behavior of infrared radiation in the atmosphere helps scientists predict climate changes and devise strategies to mitigate its effects.