Trash burning emissions
On this page we shall provide an overview of the global trash burning emissions inventory. This inventory has been incorporated into GEOS-Chem v11-02 and newer versions via the HEMCO emissions component.
Avoid double counting trash emissions
A temporary fix to turn off TRASH emissions was included in GEOS-Chem 12.0.0.
According to the CEDS publication, CEDS anthropogenic emissions already include trash emissions based on Wiedinmyer et al. (2014). To avoid double counting between the CEDS and TRASH inventories, we should not read in TRASH emissions when CEDS emissions are used (this is the default in GEOS-Chem 12). However, many regional inventories do not include trash burning emissions, so the TRASH inventory should ideally be used in those regions where this pollution source is missing.
An elegant solution for applying TRASH in certain regions, but not others has not been found yet. In an attempt to properly apply TRASH emissions, we noted the following:
- CEDS already includes trash emissions from Wiedinmyer et al. (2014). Therefore, we need to bracket the trash emissions with the (((.not.CEDS ... ))).not.CEDS to avoid double counting.
- The EPA/NEI2011 and APEI (Canada) inventories appear to already include trash burning emissions:
- From the NEI2011 technical support document (section 3.32.5, page 277): "Open burning of residential municipal solid waste (MSW) is the purposeful burning of MSW in outdoor areas. Criteria air pollutant (CAP) and hazardous air pollutant (HAP) emission estimates for MSW burning are a function of the amount of waste burned per year."
- From the APEI inventory website: "The Waste Sector includes emissions from the treatment and disposal of wastes. Sources include solid waste disposal on land (landfills), wastewater handling and waste incineration."
- Using the same methodology for applying missing emission sectors from EDGAR over Africa, we can apply TRASH emissions to specific regional inventories that don’t include trash emissions already. The complicating factor here is that the regional inventories don’t include all emitted species, so emissions for those species are still taken from global inventories. As an example, trash burning emissions don't seem to be included in EMEP. We can add TRASH emissions to the anthropogenic emissions for that region by passing cat=1, hier=10, mask=1000 so that they’re added to EMEP emissions. However, VOC emissions (e.g. ACET) are not included in EMEP and are instead provided by RETRO (cat=1/2, hier=3). Therefore ACET trash emissions will overwrite RETRO ACET emissions, which is not what is intended. That will lead to lower total anthropogenic emissions over Europe.
- We will keep trash burning emissions as a separate HEMCO category (cat=12) in an attempt to resolve zeroing RETRO VOC emissions as described above. However, this comes with new complications. CEDS now needs to be defined as cat=1/2/12 (i.e. anthropogenic + biofuel + trash). CEDS is also assigned a higher hierarchy than TRASH so that TRASH doesn’t overwrite CEDS, but that would result in zero trash (cat=12) emissions globally. From the HEMCO User's Guide, “Up to three emission categories can be assigned to each entry (separated by the separator character). Emissions are always entirely written into the first listed category, while emissions of zero are used for any other assigned category.”
- Wiedinmyer, C., R.J. Yokelson, and B.K. Gullet, Global Emissions of Trace Gases, Particulate Matter, and Hazardous Air Pollutants from Open Burning of Domestic Waste, Environ. Sci. Technol., 48, 9523-9530, doi:10.1021/es502250z, 2014.