Question

Which of the following gases is not a green house gas? (A) \(\mathrm{CO}\) (B) \(\mathrm{O}_{3}\) (C) \(\mathrm{CH}_{4}\) (D) \(\mathrm{H}_{2} \mathrm{O}\) vapour

Short answer

The gas that is not a greenhouse gas among the given options is (A) \(\mathrm{CO}\) - Carbon monoxide.

Step-by-step solution

Understand what makes a gas a greenhouse gas

A greenhouse gas is a gas that absorbs and emits infrared radiation. This property contributes to the greenhouse effect, as these gases trap heat within Earth's atmosphere, thereby increasing the planet's temperature.

Evaluate each option based on greenhouse gas properties

(A) \(\mathrm{CO}\) - Carbon monoxide does not readily absorb infrared radiation and therefore does not contribute significantly to the greenhouse effect. This is a candidate for the correct answer. (B) \(\mathrm{O}_{3}\) - Ozone absorbs and emits infrared radiation, making it a greenhouse gas. This is not the correct answer. (C) \(\mathrm{CH}_{4}\) - Methane is a potent greenhouse gas that absorbs and emits infrared radiation. This is not the correct answer. (D) \(\mathrm{H}_{2}\mathrm{O}\) vapour - Water vapour is a greenhouse gas that absorbs and emits infrared radiation, and it is the most abundant greenhouse gas in the Earth's atmosphere. This is not the correct answer.

Select the correct answer

Based on our evaluation in step 2, we can conclude that among the given options, the gas that is not a greenhouse gas is: (A) \(\mathrm{CO}\) - Carbon monoxide

Key concepts

Carbon Monoxide

Carbon monoxide, often represented as \( \mathrm{CO} \), is a colorless and odorless gas. It is produced from the incomplete combustion of carbon-containing materials. Despite being a significant pollutant, it is not classified as a greenhouse gas. This is because carbon monoxide does not effectively absorb or emit infrared radiation. Hence, it does not play a role in trapping heat in Earth's atmosphere like true greenhouse gases do.

While carbon monoxide does not contribute directly to the greenhouse effect, it can have indirect effects. For example:

• It can react with hydroxyl radicals, reducing the number available to break down methane, a potent greenhouse gas.
• In the presence of other pollutants, it can contribute to the formation of ground-level ozone, which is a greenhouse gas.

Though its impacts are complex, the primary role of carbon monoxide in atmospheric science is as an air pollutant rather than a contributor to climate change.

Infrared Radiation

Infrared radiation is a type of electromagnetic wave that falls beyond visible red light in the spectrum. Humans cannot see it, but we can feel it as heat. This is the type of radiation that greenhouse gases absorb and emit. When the Sun's visible light reaches Earth, it warms the surface, which then radiates heat back towards space as infrared radiation.

Greenhouse gases like \( \mathrm{CO}_{2} \), \( \mathrm{CH}_{4} \), and ozone trap some of this energy, capturing heat and warming the planet—a process central to the greenhouse effect.

Some key characteristics of infrared radiation include:

• Its wavelength is longer than visible light but shorter than microwaves.
• It plays a crucial role in thermal imaging technologies because it is emitted by all objects based on their heat.
• It is essential for Earth's energy balance, as it is the main way the Earth loses energy back to space.

Understanding infrared radiation is critical to comprehending why certain gases reinforce the greenhouse effect and contribute to global warming.

Greenhouse Effect

The greenhouse effect is a natural process that warms the Earth's surface. It is a vital mechanism, as without it, our planet would be too cold to support life as we know it. This effect occurs when greenhouse gases in Earth's atmosphere trap heat. When solar energy reaches the Earth, the surface absorbs it and re-radiates it as infrared radiation.

Greenhouse gases such as carbon dioxide \( \mathrm{CO}_{2} \), methane \( \mathrm{CH}_{4} \), water vapor, and ozone \( \mathrm{O}_{3} \), among others, absorb this heat and then re-emit it in all directions, including back towards Earth's surface, warming it.

Here are some points that highlight the significance and impact of the greenhouse effect:

• It maintains the Earth's average temperature at about 15°C, instead of the frigid -18°C it would be without it.
• It affects weather patterns and climate changes due to its influence on temperature regulation.
• Human activities, especially the burning of fossil fuels, have increased the concentration of greenhouse gases, intensifying the natural greenhouse effect and contributing to climate change.

Understanding the greenhouse effect is crucial for addressing global warming and environmental conservation efforts.