CALM, Carbon Accounting for Land Managers, is the first, fully-free, business based calculator showing the balance between annual emissions and carbon sequestration, of the key Greenhouse Gases (GHGs) associated with the activities of land-based businesses.
Understanding the carbon balance of a business is a vital first step towards thinking about management decisions that may have some mitigating effect on climate change by reducing GHG emissions.
STOP PRESS: The calculator has been updated with the latest UK National Inventory Report (1990-2006) data which was published in April 2008. The only factors to change are the N excretion factors. This may alter your figures.
Working through the steps below will help you calculate your carbon balance and understand the results.
- Step 1 - Why do a CALM audit?
- Step 2 - Decide your business boundaries
- Step 3 - Get your data together
- Step 4 - Register and set up your profile and log in. This step is not compulsory but is necessary if you wish to save your data. The process is quick and straightforward. Privacy is guaranteed. Additional notes can be found on the Help page.
- Step 5 - Use the CALM calculator. For more guidance visit the Help page.
- Step 6 - Go to your CALM report by clicking "View onscreen report". A pdf report is also available. For more guidance on reading the reports visit the Help page.
- Step 7 - Use the mitigation advisory notes to assess ways you can improve your carbon balance. These can be found in your CALM report or are available as a pdf download. Guidance notes found on the Help page.
The Further Reading page gives more information and web links to the references and sources used in our research for CALM. Click to see how CALM fits the international guidelines for greenhouse gas accounting.
"CALM is an excellent first step, and offers a useful tool to land-managers" Prof. Gareth Edwards-Jones Professor of Agriculture & Land-Use Studies at the University of Wales, Bangor (CALM peer reviewer).




