This project has compiled and improved the Taiwan National Greenhouse Gas Inventory of Waste Sector from 1990 to 2015 using methodologies consistent with those recommended in the 2006 Intergovernmental Panel on Climate Change Guidelines for National Greenhouse Gas Inventories (IPCC 2006 Guidelines). The methodologies for estimating greenhouse gas (GHG) emissions from the Waste Sector described in the National Inventory Report submitted by the Annex I parties in 2017 have been reviewed and analyzed to understand and identify the latest international trends, emission trends, and focal points of inventory review reports. The European policies towards a circular economy including the strategies and evaluation of achieving GHG emission reduction targets were reviewed for better waste management practices. The following efforts were made to identify the benefits of GHG mitigation strategies. Solid waste disposal sites were visited to study the effects of landfill mining operation on reducing CH4 emissions. Domestic and industrial wastewater treatment plants were also visited to identify the benefits of biogas recovery for CH4 emission reduction as well as economic benefits analysis and feasibility study. On-site GHG emissions of industrial wastewater treatment plants have been measured at the second phase of the development of country-specific emission factors. In addition, the methodologies with a reasonable choice of emission parameters for estimating CH4 and N2O emissions from domestic and industrial wastewater treatment and CH4 emissions from industrial wastewater treatment were both studied. The differences in GHG emissions between before and after improving the methodologies were also compared. Concrete conclusion and suggestion with respect to the survey results and mitigation benefits of landing mining, biogas recovery from wastewater treatment plants, and development of country-specific emission factors for industrial wastewater treatment plant have been made after 3 review meetings with the experts. Both Approach 1 (propagation of error) and Approach 2 (Monte Carlo method) were used for the uncertainty analysis of emission estimates in 2015. The level and trend uncertainty from 2013 to 2015 are shown to demonstrate the history of inventory improvement. The Taiwan National Greenhouse Gas Inventory of Waste Sector from 1990 to 2015 has been compiled and submitted by the inventory review process. The GHG reduction action plan for the environment-related sector has been developed. Finally, the promotion materials of the GHG inventory of waste sector were published. The changes in greenhouse gas emissions from the waste sector show that emissions were the highest in 1996 and there was a reduction trend since 2000. The largest contributor to the emissions by category was changed from solid waste disposal to wastewater treatment since 2010. Over the past 10 years, emissions have decreased substantially and gradually from solid waste disposal and domestic wastewater treatment, respectively. However, emissions from industrial wastewater treatment have increased. In 2015, the largest three contributors accounting for 96.5% were domestic wastewater treatment, industrial wastewater treatment, and solid waste disposal. Emissions from the waste sector resulted in 4,108.8 kt-CO2 eq. Among the waste sector emissions in 2015, the largest contributor was domestic wastewater treatment accounting for 39.1%, followed by industrial wastewater treatment accounting for 29.6%, solid waste disposal accounting for 27.7%, incineration of waste accounting for 2.6%, and biological treatment of waste accounting for 0.9%. Breakdown of emissions in 2015 by gas shows that the largest contributor to the emissions is CH4 accounting for 88.7%, followed by N2O accounting for 8.8%, and CO2 accounting for 2.5%. The emissions from this sector had decreased by 53% compared with 2005 levels and decreased by 5.8% compared with 2014 levels.

Greenhouse gas, waste sector, national inventory report (NIR), local emission parameter, mitigation benefits