Last edited Thu Nov 14, 2024, 08:46 AM - Edit history (1)
Water vapor is not emitted directly by human activities like other greenhouse gases (CO₂, CH₄, N₂O, etc.). Instead, it acts as a feedback mechanism. As the atmosphere warms due to increased greenhouse gas concentrations, the amount of water vapor in the air increases. This is because warmer air can hold more moisture.
The increase in water vapor can be quantified indirectly through its relationship with temperature and other greenhouse gases. For instance, if the global temperature rises by about 1°C (a common projection by 2030 depending on emissions scenarios), the atmosphere's water vapor content could increase by about 7% per degree Celsius rise.
Water Vapor's Role:
Water Vapor in 2019: At the current global temperature and humidity levels, the atmosphere typically contains about 12,900 gigatons of water vapor.
Water Vapor in 2030: If the temperature rises by 0.5–1°C over the next decade (depending on the emissions path), water vapor levels could rise by 3.5–7% in total.
Example Calculation of Projected Water Vapor Change:
1. 2019 Estimate: 12,900 gigatons of water vapor in the atmosphere.
2. Projected 2030 Estimate (assuming a 1°C increase):
gigatons.
Percentage Difference:
Percentage Increase (2019–2030):
~7% increase in water vapor due to higher temperatures and associated humidity increases.
This increase is not directly due to human emissions of water vapor, but rather an amplification effect from rising global temperatures caused by other greenhouse gases.
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