What is Global Warming Potential (GWP)?
GWP is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific period (usually 100 years) compared to CO₂. It provides a standard scale for comparing the impact of different GHGs.
- Examples:
- CO₂: GWP of 1 (baseline)
- Methane (CH₄): GWP of 28 (i.e., 1 tonne of CH₄ has the same warming effect as 28 tonnes of CO₂ over 100 years)
- Nitrous Oxide (N₂O): GWP of 265
- Fluorinated Gases (e.g., HFCs, PFCs, SF₆): GWPs ranging from hundreds to thousands.
Sample Calculation for CO₂e
- Formula: CO₂e = ∑(Mass of GHG × GWP of GHG)
- Example: If an emission source releases 1 tonne of CH₄ and 1 tonne of N₂O, the total CO₂e would be: CO₂e = (1 tonne of CH₄ × 28) + (1 tonne of N₂O × 265) = 28 + 265 = 293 tonnes CO₂e