Harmonization of CARB's Cal e-GGRT and EPA's e-GGRT
Note: The Cal e-GGRT help system includes general instruction on using the California GHG reporting tool. However, the help system may not explain differences between California and U.S. EPA reporting requirements. Please refer to the ARB reporting website for California-specific reporting requirements and additional help.
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The California Air Resources Board (CARB) has been working with the U.S. EPA to develop and launch an electronic tool that supports GHG reporting under AB 32 (California’s Mandatory GHG Reporting Program). Cal e-GGRT was launched on February 22, 2012.


At the time the US EPA finalized its Mandatory Reporting of Greenhouse Gases Rule (40 CFR Part 98), more than a dozen states already had or were in the process of implementing their own greenhouse gas data collection programs, including California. As part of its commitment to work with states to harmonize data systems and, where possible, reduce reporter burden, EPA launched a State-EPA Integrated Project Team (IPT) on greenhouse gas data collection and exchange in 2010. Development of Cal e-GGRT was an outgrowth of this effort. Cal e-GGRT supports CARB’s effort to harmonize its GHG data collection efforts under AB32 with EPA’s Greenhouse Gas Reporting Program. Beginning with the submittal of 2011 data, CARB’s annual GHG data reporting methods will gradually align with many of EPA’s requirements. Over the next several years, CARB intends to harmonize its program with EPA’s. The Cal e-GGRT reporting framework and “look and feel” is similar to EPA’s e-GGRT system and should be familiar to California users of EPA’s e-GGRT.


The launch of Cal e-GGRT is the first step in CARB’s efforts to harmonize its greenhouse gas reporting program with EPA’s. In the future, CARB and EPA hope to develop a system that will allow California reporters subject to both state and federal requirements to use one system to enter their data.

Questions & Answers

Who will use Cal e-GGRT?
Approximately 700 facilities and suppliers subject to California’s mandatory greenhouse gas reporting program will use Cal e-GGRT to meet their annual reporting requirements.

Why do CARB reporters need a separate tool from U.S. EPA e-GGRT?
Cal e-GGRT includes numerous modifications to support California's cap-and-trade program, verification, and other CARB programs. Because of the differences between CARB and U.S. EPA reporting requirements, data submitted to U.S. EPA will not meet ARB reporting requirements. Therefore, separate reporting to Cal e-GGRT is required.

How many CARB reporters are also required to report GHG data to EPA?
California estimates that approximately 550 reporters under the California mandatory greenhouse gas reporting program will also report annual GHG data to EPA under 40 CFR Part 98.

What are some of the differences between CARB’s program and EPA’s?
Primary areas where the programs differ are in the areas of transportation fuels (CA reporters are the terminal racks and not refineries), and also imported electrical power entities. CA also requires reporting of data that would be considered confidential business information, that EPA deferred (see 76 FR 53057, August 25th, 2011).

Can a California reporter use Cal e-GGRT to report their GHG data to EPA?
No, the two systems are currently independent. However CARB and EPA hope to continue their collaboration so that the ability to use one tool to enter data for both programs would be possible in the future.

Reporting Tool - https://ssl.arb.ca.gov/Cal-eGGRT/login.do
Help Content Homepage - Home
Reporting Tool - https://ghgreporting.epa.gov
Help Content Homepage - http://www.ccdsupport.com/confluence/display/help/Home

This web site is maintained by a contractor to the California Air Resources Board (RY2015.R.03)