Nevada Statewide Greenhouse Gas Emissions Inventory and Projections, 1990 to 2030
Nevada Statewide Greenhouse Gas Emissions Inventory and Projections, 1990 to 2030
1. Introduction
1.1
Overview
During the 2007 Nevada Legislative Session, the legislature passed Senate Bill 422, which is now codified
in the Nevada Revised Statutes (NRS) Chapter 445B.137 and 445B.380. NRS 445B.137 defines the gases
that are collectively referred to as greenhouse gases (GHG) and NRS 445B.380 requires that a statewide
GHG inventory be prepared and issued at least every 4 years beginning in 2008. It further stipulates that
the report must include the origin, types, and amounts of GHGs emitted throughout the state, and all
supporting analyses and documentation. This report represents a comprehensive inventory of all
anthropogenic GHG emissions in Nevada as it considers all 6 GHGs listed in NRS 445B.137: carbon
dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFC), perfluorocarbons (PFC),
and sulfur hexafluoride (SF6). This report was developed using the United States Environmental
Protection Agency's (EPA) State Inventory Tool (SIT).¹
1, 2 The SIT is a series of emissions calculators
broken up by sectors designed to help states develop GHG inventories (the SIT is discussed in more
detail in 1.2).
The GHGs considered in this report each have characteristic global warming potentials (GWPs) and
therefore contribute to the overall atmospheric greenhouse effect differently. The GWP is used to
derive a common metric, known as the CO2 equivalent (CO2eq), which uses the GWP of CO2 as a
reference unit. The biggest difference in values between this report and the 2012 version is that the
2012 report used GWPs from the International Panel on Climate Change's (IPCC) third assessment and
this report utilizes the GWPs from the IPCC's fourth assessment. Table 1-1 lists the GWPS on a 100 year
horizon for the gases considered in this report. The use of CO2eq allows estimating and comparing total
GHG emissions from sources emitting different GHGs.
3,4
Table 1-1: The 100 Year Global Warming Potentials (GWPs) for Selected GHGs
Gas
GWP
CO₂
1
CH4
25
N₂O
298
HFC-23
14,800
HFC-32
HFC-125
675
3,500
1
The six GHG gases listed in NRS 445B.137 are similarly included in the definitions of a GHG by the International
Panel on Climate Change (IPCC) and by the United States Environmental Protection Agency (EPA).
2
3
https://www.epa.gov/statelocalclimate/state-inventory-and-projection-tool (accessed October 2016).
IPCC (2007) Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth
Assessment Report of the Intergovernmental Panel on Climate Change. [S. Solomon, D. Qin, M. Manning, Z. Chen,
M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press. Cambridge, United Kingdom
996 pp.
4
While the Intergovernmental Panel on Climate Change (IPCC) has since updated the GWPS for the GHGs listed in
Table 1-1, the modeling software provided by the EPA that is used in this report has not been updated to reflect
those changes. The IPCC's most recent GWP's are published in their fifth assessment:
https://www.ipcc.ch/report/ar5/ (accessed October 2016).
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