INTRODUCTION
IMPLAN’s environmental data come from the U.S. Environmental Protection Agency (EPA) and consist of ratios representing physical emissions or inputs per dollar of industry output, with the physical unit depending on the particular pollutant or input under consideration. The total amount of emissions/inputs comes directly from the EPA, while the output used to create ratios comes from IMPLAN. The EPA data has somewhat less sector-specificity than the IMPLAN data, so the total amount of emissions/inputs may be mapped to more than one IMPLAN sector. This means that ratios for each IMPLAN sector should be unique, despite sharing the numerator of total emissions across a few industries. These ratios can be used to gain insight into some of the environmental impacts associated with a given economic impact modeled via the IMPLAN system. They can also be used to compare environmental footprints across geographies or time.
IMPLAN does its very best to provide accurate regional economic models, just as the EPA does its very best to provide accurate industry-specific environmental coefficients. It is upon the analyst to understand the IMPLAN data and input-output modeling framework, including its limitations, and to employ best practices when using the IMPLAN system, in which case the resulting associated environmental impacts and/or footprints can be taken seriously.
CHANGE IN USEEIO VERSION
This release of IMPLAN’s environmental data is the first in which we use the EPA’s United States Environmentally-Extended Input-Output (USEEIO) table version 2.0. The first release of IMPLAN’s data used the first iteration of the USEEIO model (1.0) which contained less current data and varying satellite accounts. For full details on this model, please see USEEIO v2.0, The US Environmentally-Extended Input-Output Model v2.0.
Of note is that environmental ‘tags’ are removed as a result of this shift. The new organizational method employed defines environmental flowables according to their ‘context'.
UPDATES TO CATEGORIES OF ENVIRONMENTAL DATA
Changes in the source data for this product resulted in a change in the number and contents of all satellite tables for our environmental data. The below images provide a mapping reference between the tables found in the first and second releases. The years in parentheses indicate the year in which the ratios for each compound were sourced from.
In addition to the nine tables above, new tables have also been added for Commercial Non-Hazardous Waste From Construction Activities (2014); Commercial RCRA-Defined Hazardous Waste (2017); and Commercial Non-Hazardous Waste Excluding Construction (2015).
Of note, the Water Use and Emissions table also no longer includes estimates for releases back to the water. The ‘emissions’ context found within the data refers solely to water that is removed from the environment due to evaporative loss as a result of industry activity, and thus results for water use can now be summed without having to manually edit out water releases to create a net value.
Below is the list of the 12 broad Categories of Environmental Data we have, listed by table acronym pulled directly from the USEEIO model:
- CHAIR (Criteria and Hazardous Air Emissions)
- Examples:
- Nitrogen Dioxide
- Chromium III
- Formaldehyde
- Styrene
- Chlorine
- Examples:
- CNHW (Commercial Non-Hazardous Waste From Non-Construction Activities)
- Examples:
- Tires
- Ash
- Aluminum Cans
- Paper Bags
- Examples:
- CNHWC (Commercial Non-Hazardous Waste From Construction Activities)
- Examples:
- Asphalt Pavement
- Bricks
- Cardboard
- Glass
- Drywall
- Examples:
- CRHW (Commercial RCRA-Defined Hazardous Waste)
- Examples:
- Dried Paint
- Sodium Azide
- Waste Oil
- 2-Butanone
- Examples:
- GHG (Greenhouse Gasses)
- Examples:
- CO2
- N2O
- Sulfur Hexafluoride
- Examples:
- GRDREL (Point Source Industrial Releases to Ground)
- Examples:
- Ammonia
- Lead
- Zinc compounds
- Mercury
- Anthracene
- Examples:
- LAND (Land Use)
- Examples:
- Land use by m2*a
- Examples:
- MINE (Mineral Extraction)
- Examples:
- Copper
- Lead
- Gold
- Examples:
- NPAG (Nitrogen and Phosphorus Releases from Agriculture)
- Examples:
- Nitrogen
- Phosphorus
- Examples:
- PEST (Pesticide Releases)
- Examples:
- Pyraclostrobin
- Imazamox
- Carbaryl
- Examples:
- WAT (Water Withdrawals)
- Examples:
- Water, fresh (emission and resource)
- Water, saline
- Examples:
- WATREL (Point Source Releases to Water)
- Examples:
- Formaldehyde
- Nitrogen
- Zinc
- Aluminum
- Examples:
ADDITION OF THE ReCiPe LCIA DATA
IMPLAN Estimates of Land Use and Greenhouse Gasses now also include equivalencies data from the ReCiPe method of Life Cycle Impact Assessment (LCIA). These data extrapolate upon what is already available for Greenhouse Gasses and Land Use, allowing users to compare the environmental damages caused by resource use or flowable pollution in a more equitable fashion.
Land Use data contains measures for converting land used into Characterization Factors (CF) for occupation or transformation of land in terms of annual crop equivalents. Annual crop equivalents place varying types of land use into a comparable state. For example, plots of land with separate contexts such as agricultural and urban human-dominated lands can be converted into an equivalent measure in meters squared for comparison to one another in terms of impact to the environment. In IMPLAN, this unit is expressed as CFocc (annual crop eq). Furthermore, these annual crop equivalents can be converted to endpoint units of species loss per year per meter squared of annual crop equivalents, represented in IMPLAN as Species/M2 annual crop eq.
Greenhouse gas emissions data contain measures for converting greenhouse gasses into Carbon Dioxide equivalents, such that analysts can compare the Global Warming Potential (GWP) of each gas to one another. Conversions are available for kilograms of Carbon Dioxide equivalents per kilograms of each greenhouse gas (kg CO2 eq/ kg GHG). Ratios are available to represent global warming potential over 20 years, 100 years, and 1000 years.
"GWP20, 100, 1000" refers to the "Global Warming Potential" of a greenhouse gas, with "20" indicating the potential over a 20-year timeframe, and "100" signifying the potential over a 100-year timeframe, and "1000" signifying the potential over a 1000-year timeframe. The EPA typically uses the "100-year GWP" to compare the environmental impact of different greenhouse gases, meaning they consider how much heat a gas will trap over a 100-year period relative to carbon dioxide (CO2) which is assigned a GWP of 1 per kilogram. To learn more about GWP, read the EPA’s Understanding Global Warming Potentials.
REFERENCES
Yang, Y., W.W. Ingwersen, T.R. Hawins, M. Srocka, and D.E. Meyer, 2017. USEEIO: A new and transparent United States environmentally extended input-output model. Journal of Cleaner Production, 158: 308-318.
Written November 9, 2023
Updated October 31, 2024