Emission trends

With total 2005 emissions of approximately 1300 MtCO₂-eq/yr, the waste sector contributes about 2–3% of total GHG emissions from Annex I and EIT countries and 4–5% from non-Annex I countries (see Table TS.13). For 2005–2020, business-as-usual (BAU) projections indicate that landfill CH₄ will remain the largest source at 55–60% of the total. Landfill CH₄ emissions are stabilizing and decreasing in many developed countries as a result of increased landfill gas recovery combined with waste diversion from landfills through recycling, waste minimization and alternative thermal and biological waste management strategies. However, landfill CH₄ emissions are increasing in developing countries because of larger quantities of municipal solid waste from rising urban populations, increasing economic development and, to some extent, the replacement of open burning and dumping by engineered landfills. Without additional measures, a 50% increase in landfill CH₄ emissions from 2005 to 2020 is projected, mainly from the Non-Annex I countries. Wastewater emissions of CH₄ and N₂O from developing countries are also rising rapidly with increasing urbanization and population. Moreover, because the wastewater emissions in Table TS.13 are based on human sewage only and are not available for all developing countries, these emissions are underestimated (high agreement, medium evidence) [10.1, 10.2, 10.3, 10.4].