The Greenhouse Gas Bulletin (GGB) issued by the World Meteorological Organization (WMO) provides a detailed analysis of the concentrations of long-lived greenhouse gases (LLGHGs) in the atmosphere and their impact. This bulletin is helpful in understanding changes in atmospheric composition and its effects on climate. The GAW program monitors interactions between the atmosphere, oceans, and the Earth’s biosphere and observes the concentrations of long-lived greenhouse gases such as CO₂, CH₄, and N₂O.
Key Points of GGB
- Concentration levels: Based on global average surface concentrations in 2023, the concentration of CO₂ has increased by 151%, methane (CH₄) by 265%, and nitrous oxide (N₂O) by 125% since 1750 (pre-industrial levels).
- Increase in radiative forcing: Radiative forcing from long-lived greenhouse gases is projected to increase by 5% from 1990 to 2023, with CO₂ alone contributing 81%. Radiative forcing measures how these gases affect the Earth’s energy balance, leading to warming.
- Atmospheric methane increase: There has been a record increase in atmospheric methane (CH₄) over the past three years, caused by higher emissions from natural wetlands due to climate change.
- Impact on climate change: Rising temperatures and ocean acidification can cause ecosystems to emit more greenhouse gases, wildfires can increase CO₂ emissions, and oceans can absorb less. All of this can exacerbate global warming.
Radiative forcing and its importance
- Radiative forcing represents the amount of energy added or removed from the climate system per unit area. When greenhouse gases trap heat, this heat warms the Earth, causing climate imbalances.
Introduction to World Meteorological Organization (WMO)
- Specialized agency of the United Nations: WMO is headquartered in Geneva, Switzerland.
- Founded: 1950.
- Membership: It has 187 member states (including India) and 6 member territories.