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COBRA – Revision History

This page describes the revisions and updates made to the CO-Benefits Risk Assessment (COBRA) Screening Model since October 2017.

October 2, 2017

EPA released version (3.0) which includes several enhancements, including: 

  1. An improved user interface with more flexible mapping functionality.
    1. With this version of COBRA, users can: customize the map color scheme, modify map interval breaks, explore data geospatially by selecting for specific attributes, and export maps for use in GIS programs.​
  2. New features that enable advanced users to import custom baseline and scenario emissions files, population datasets, incidence datasets, health effect functions, and valuation functions.
    1. This functionality makes it possible to use COBRA for years other than the preloaded 2025 baseline.
  3. An additional analysis year, 2025, so for each COBRA run, users can now select the previously available 2017 baseline or the newly added 2025 baseline. Sources of the new 2025 data include:  
    1. Emissions data: The COBRA 2025 emissions baseline uses emissions data from EPA’s 2011 Version 6.2 Air Emissions Modeling Platform (2011v6.2 platform) to forecast ambient 2025 PM2.5 levels
    2. Population data: COBRA uses 2025 population projections based on US Census of Population and Housing 2010 and economic forecasting models developed by Woods & Poole (2012). 
    3. Incidence data: COBRA 2025 baseline mortality incidence is based on 2025 national-level Census mortality rate projections. 
    4. Valuation data: For consistency with the 2025 COBRA emissions baseline year, all unit values were adjusted for historical/projected growth in real U.S. income between the year of the original unit value estimate and 2025. The 2025 health values, like the 2017 values, are expressed in terms of 2010 U.S. dollars

       (Note: the 2017 baseline remains unchanged from version 2.71)