Question

Name any two gases responsible for causing greenhouse effect.

Hint:

Water vapor ($H_2O$) is actually the most abundant natural greenhouse gas in the atmosphere. However, human-produced emissions of carbon dioxide ($CO_2$) and methane ($CH_4$) are the primary drivers of modern global climate change.

Answer 1

Step 1: Understanding the Greenhouse Effect:
The greenhouse effect is a natural physical process where specific atmospheric gases absorb infrared thermal radiation emitted by the Earth and re-radiate it in all directions. This traps heat in the atmosphere, maintaining temperatures that support life. However, excessive human emissions of these gases are intensifying the effect, leading to global warming.

Step 2: Molecular Criteria for Greenhouse Gases:
To absorb infrared light, a gas molecule must be asymmetrical or be able to bend and vibrate in ways that change its net electrical dipole moment. Symmetrical, homonuclear diatomic gases like Nitrogen ($N_2$) and Oxygen ($O_2$) cannot do this, so they are not greenhouse gases.

Step 3: Listing Primary Greenhouse Gases:
Two major gases responsible for the greenhouse effect are:

• Carbon Dioxide ($CO_2$): The most prevalent anthropogenic greenhouse gas, released primarily through burning fossil fuels, deforestation, and industrial processes.
• Methane ($CH_4$): An extremely potent greenhouse gas with a global warming potential significantly higher than $CO_2$ over a 100-year timescale. It is released through agricultural activities (such as livestock digestion), landfills, and fossil fuel extraction.

Other notable examples include Water Vapor ($H_2O$), Nitrous Oxide ($N_2O$), and Chlorofluorocarbons (CFCs).