WARM USERS 6UIDE
Calculating Greenhouse Gas Emissions
With the WAste Reduction Model
WHAT i$ THE WA$TE
REDUCTION MODEL?
"TTie WAste Reduction Model (WARM)
I was created by the U.S. Environmen-
tal Protection Agency (EPA) to help solid
waste planners and organizations estimate
greenhouse gas (GHG) emission reduc-
tions from several different waste manage-
ment practices. WARM is available in a
Web-based calculator format and as a
Microsoft Excel® spreadsheet. Both ver-
sions of WARM are available on EPAs
Web site at www.epa.gov/mswclimate.
WARM calculates and totals GHG emis-
sions of baseline and alternative waste
management practices—source reduc-
tion, recycling, combus-
tion, composting, and
landfilling. The model cal-
culates emissions in metric
tons of carbon equivalent
(MTCE)1 across a wide
range of material types that
compose municipal solid waste
(MSW). In addition, the
Microsoft Excel® version can
break down emission results by
type of GHG (carbon dioxide,
methane, etc.). The user can con-
struct various scenarios by simply entering
data on the amount of waste handled by
material type and by management practice.
WARM then automatically applies emis-
sions factors specific to material type and
management practice to calculate the GHG
emissions of each scenario. Several key
inputs, such as landfill gas collection and
transportation distances to MSW facilities,
can be modified by the user.
The GHG emissions factors were devel-
oped following a life-cycle assessment
methodology using estimation techniques
developed for national inventories of
GHG emissions. EPAs report Greenhouse
Gas Emissions From Management of
Selected Materials in Municipal Solid Waste
(EPA 530-R-98-013) describes this
methodology in detail. For a free copy of
this report, visit www.epa.gov/mswclimate
or call EPAs RCRA hotline at 800 424-
9346.
WHO SHOULD U$E
WARM?
WARM was developed for
solid waste managers (from
state and local governments and
other organizations) who want
to calculate the GHG emissions
associated with different waste
management options. Emis-
sions estimates provided by
WARM are intended to sup-
port voluntary GHG mea-
surement and reporting
initiatives. These initia-
tives include waste manage-
ment components of climate change
action plans, the Department of Energy's
I605(b) voluntary program for reporting
GHG emissions, and other waste manage-
ment projects for which an understanding
of GHG emissions is desired.
U$iN6 WARM
Before using WARM, you first need to
gather data on your baseline waste manage-
ment practices and an alternative scenario.
^MTCE is a unit of measurement that expresses the heat-trapping effects of various green-
house gas emissions in carbon equivalents. An international protocol has established carbon
dioxide (CO2) as the reference gas.
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You should know how many tons of waste you manage
(or would manage) for a given time period under each
scenario by material type and by management practice.
Both models allow you to customize your results based on
project specific landfill gas recovery practices and trans-
portation distances. Note that you may use default values
if you are unsure of landfill gas recovery practices and/or
transportation distances.
Web-based Version:
To use the web-based version of WARM, you
will need Internet Explorer or Netscape versions 4 or
higher.
• For the web-based WARM model to be able to cal-
culate your GHG emissions you must enter the tons of
each material type managed into the baseline and alterna-
tive management tables. The boxes in the baseline and
alternative tables correspond to specific material types and
management practices. Be sure to enter your data in the
correct boxes.
MSW Material Types
Recognized by WARM
Newspaper Glass
Office Paper HOPE
Corrugated LDPE
Boxes PET
Mixed Paper* Dimensional
Aluminum Lumber
Food
Discards
Yard
Trimmings
Mixed
Recyclables
Steel Cans
Density
Fiberboard
* Broad. Residential, and Office
Answer the questions pertaining to landfill gas recovery
and trsnsportation distance by selecting the appropriate
toggle buttons. If the requested data is not available,
WARM will use the national average defaults.
• Once you've completed the tables and answered all
of the questions on the inputs page, WARM has all the
information it needs to calculate the GHG emissions
associated with the baseline and alternative waste man-
agement scenarios you specified. Click "create summary"
to see your results.
• The summary sheet provides a concise report of
GHG emissions from the baseline and alternative waste
management scenarios, as well as a net emissions figure.
Once you have seen your results, you can return to the
inputs page to run additional scenarios by selecting the
button labeled "exit summary."
Alternatively, you can view the emission factors used to
estimate emissions for various materials and management
practices; note that these emission factors will reflect
national average default values for landfill gas recovery
and transportation distances. To access these emission fac-
tors, select the button labeled "view emission factors"
from either the inputs page or the summary page.
Microsoft Excel® Version:
To use Microsoft Excel® WARM, you will need
Microsoft Excel® version 5.0 or higher.
• Once you've gathered these data, you're ready to get
started with WARM. Follow directions on the Web site
for downloading and installing the Microsoft Excel® ver-
sion of WARM. After successfully downloading the file,
open the spreadsheet. WARM will prompt you with
"Open as read-only?" If you plan to save your work in
WARM, click "No." Otherwise, click "Yes." Next,
WARM will prompt you with "This document contains
links. Re-establish links?" Simply click "No."
WARM Summary Report
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• Now, click on the "Analysis Inputs" tab at the bottom
center of the screen to open the input sheet. Follow the
instructions for Steps 1 and 2 to fill in the tables describing
your baseline and proposed alternative waste management sce-
narios.
Fill in the data requested in Steps 3—6. In these steps,
WARM is asking for additional waste handling information to
allow it to customize its calculations to your waste manage-
ment situation. For example, you are asked for data on trans-
portation distances and on your landfill gas and ferrous metal
recovery systems, if applicable. If the requested data is not
available, WARM will use the national average defaults.
Once you've completed Steps 1—6 on the "Analysis
Inputs" sheet, WARM has the information it needs to calcu-
late the GHG emissions attributable to the baseline and alter-
native waste management scenarios you've specified. Emissions
calculations are presented on three separate output sheets, as
described below. From the "Analysis Inputs" sheet, click on a
tab at the bottom of the screen for the results sheet you want
to view first.
— The "Analysis Results" sheet shows GHG emissions for each
scenario in units of MTCE. You can compare the total impact
of the baseline and alternative scenarios, or, if you want more
detail, you can scroll down to view GHG emissions per mate-
rial type and management practice.
— The "Analysis Results by Gas" sheet provides a breakout of
emissions of specific GHGs per material type under each sce-
nario. The specific GHGs are carbon dioxide (CO 2), methane
(CH^), nitrous oxide (N2O), and perfluorocarbons (CF^ and
— The "Summary Report" sheet provides a concise report of
GHG emissions from the baseline and alternative waste
management scenarios, as well as a net total MTCE figure.
Assistance
If you need additional asistance with using WARM, please
email Henry Ferland at ferland.henry@epa.gov or Eugene Lee
at lee.eugene@epa.gov.
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