No, achieving exactly 0% humidity is considered practically impossible on Earth.
Even in the driest environments, trace amounts of water vapor are typically present in the air. The concept of humidity refers to the amount of water vapor present in the air. Relative humidity, specifically, expresses this amount as a percentage of the maximum amount of water vapor the air can hold at a given temperature.
Therefore, even in extremely arid conditions like the Atacama Desert, it's highly improbable to find air completely devoid of water molecules, preventing a reading of 0% relative humidity. The presence of even minute amounts of water vapor means there's always some degree of humidity.
Factors contributing to this impossibility include:
- Evaporation from water bodies: Oceans, lakes, rivers, and even damp soil contribute to atmospheric moisture through evaporation.
- Transpiration from plants: Plants release water vapor into the atmosphere through transpiration.
- Human activities: Industrial processes, agriculture, and even daily human activities introduce water vapor into the air.
While controlled laboratory environments might theoretically achieve near-zero humidity, such conditions are not naturally occurring or sustainable in the Earth's environment.
In summary, while extremely low humidity levels are possible, truly achieving 0% humidity in a natural setting on Earth is an impossibility due to the constant presence of at least trace amounts of water vapor in the atmosphere.
