Non-CO2 greenhouse gases (GHGs) such as methane (CH4) and nitrous oxide (N2O) play a critical role in global warming and are essential components of comprehensive GHG inventories. Although CO2 is the most abundant and well-known GHG, CH4 and N2O have much higher global warming potentials (GWPs) over shorter time horizons—approximately 28-34 times for methane and around 265-298 times for nitrous oxide over 100 years. Methane primarily originates from agriculture (e.g., enteric fermentation), waste management, and fossil fuel extraction, while nitrous oxide emissions come mainly from agricultural soil management, industrial activities, and biomass burning. Including these gases in inventories is vital for accurately assessing a country’s or sector’s total climate impact and for designing effective mitigation strategies. Because of their potency and different atmospheric lifetimes, targeting CH4 and N2O reductions can yield faster climate benefits compared to CO2 alone. Accurate accounting of these gases helps policymakers prioritize actions, meet international reporting obligations (such as under the UNFCCC and IPCC guidelines), and track progress toward climate goals. Ignoring non-CO2 gases can lead to significant underestimation of emissions and undermine climate mitigation efforts.

Published on: 2026-01-24 at 00:15:01