Explain how infrared spectroscopy can monitor gases such as CO2, CH4 and H2O.

Infrared spectroscopy is a technique used to monitor gases like CO2, CH4, and H2O by measuring the absorption of infrared radiation. Each gas has specific vibrational modes that correspond to distinct wavelengths of infrared light. When infrared radiation passes through a sample, certain wavelengths are absorbed by the gas molecules, causing them to vibrate. By analyzing the absorption spectrum, we can identify the presence and concentration of these gases. This method is crucial for environmental monitoring and understanding atmospheric changes.