Skip to content


Folders and files

Last commit message
Last commit date

Latest commit


Repository files navigation

DOI DOI License: GPL v3 Contributor Covenant


cerc-web is the web interface to the Climate Equity Reference Calculator. It is mainly written in PHP with some user interface elements written in javascript to achieve dynamic interactivity.


You will need a web server with php enabled and sqlite3 installed. The web server must be permissible enough to allow compiled executables (the calculator engine) to be run by the php process. You will also need a MySQL database server that is accessible from the web server. Finally, you need a way of compiling the calculator engine from its C source code for whatever operating system your web server is running.


Pre-installed docker file

Since installation of cerc-web is a bit complicated, a self-containing docker image with all of the required code elements and dependencies is available at The Dockerfile used to build the docker image from source and further details (e.g. download and run instructions) are also contained in the docker sub directory of this repository. Docker is free virtualization software, is available for all major operating systems, and can be downloaded from

Your own Installation

This repository contains all files of the web interface, however, there are several databases to obtain and/or create and you also need to obtain or compile an executable of the calculator "engine." Instead of installing your own version of the software, you can also simply head over to where the authors maintain a fully functional installation of the calculator.

  1. Install the web interface files: Download or check out the files in this repository and put them on any php-capable web server.
  2. Obtain and/or create databases.
    1. Obtain a "core" database. The authors maintain the calculator's "core" database as an SQLite3 database which is published in the Harvard Dataverse. Within the Dataverse data repository you will want to find the .sql3 file and download it. For most purposes we recommend the most recent version, but you can also pick any other version or create a core database yourself. This might be of interest for example if you want to assess a different mitigation pathway or effort sharing between entities other than the countries provided (for example, @krueschan has created a core database for Canadian provinces). Contact us if this is of interest.
    2. Put the core database on the same webserver, since it's SQLite, it is fully contained in a single file. Make sure the file's location and permissions allows the php process of your server to have read/write access to it.
    3. Create a "pledge" database. The pledge database is a MySQL database, so you need a MySQL server that can be accessed from the webserver where you put the web interface code. The repository includes a sql file which can be run on your MySQL server to create the necessary database structure. From time to time we dump our own current pledge database in the same folder in the repository. Contact us if you want our most recent version, but you can also run cerc-web with an empty pledge database. Or enter your own quantifications of pledges using the included pledgedb manager.
    4. Create a "helptext" database. The helptext database is a MySQL database. Similar to the pledge database, an sql file exists to assist you in creating this database on your server.
  3. Obtain and/or compile the Climate Equity Reference calculator "engine," which is also released as open source package and can be obtained on SourceForge.
  4. Rename the file to config.php and enter the relevant information, in particular, the location of the engine and the core database file as well as the connection data to the two MySQL databases you created above. Typically, this will also involve the creation of temporary folders and such; make sure to set those folders' permissions such that the php process on your server has read/write access to them.
  5. Done.

Contact and trouble shooting

If you run into issues, feel free to create a ticket on Github, or contact us via There is also more information available on how to contribute to the project.

Please note that cerc-web has adopted the Contributor Covenant v1.4.1 which is a Code of Conduct that describes the conduct expected of everybody who interacts with this project. The Contributor Covenent is an initiative to make the Open Source Software community a more inclusive, safe and welcome place and cerc-web is proud to be part of it.