Carbon Footprint Calculators
What to consider when deciding which calculator tool to use?
- It is recommended that the same calculator tool is used year on year in order to provide a more accurate monitoring system as calculations do vary considerably between tools.
- Each calculator makes different assumptions and considers different factors.
- The greater the energy consumption on a farm, the more difference there are between the tools because embedded calculations are magnified.
Below are brief introductions to a selection of carbon calculators.
CALM Carbon Calculator
CALM is an abbreviation for Carbon Accounting for Land Managers. The CALM Carbon Calculator has been produced by the Country Land and Business Association (CLA) in partnership with Savills. It measures the emissions of GHGs in relation to energy and fuel use, livestock, cultivation and land-use change and application of nitrogen fertilisers and lime against any carbon stored in trees and soil. It is not a measure of carbon capture (sequestration) but rather the annual change in emission pre and post entry.
The free web-based calculator allows the user to input a lot of data and therefore gives the impression that little is assumed. For example, in terms of livestock, the user can specify details such as livestock numbers, age, amount of days per year grazing and what percentage of manure is produced and stored as FYM or slurry. It also allows the user to input a lot of detail in terms of fuel consumption and nitrogen content of fertilisers. Less detail is required in terms of carbon sequestered by woodlands and consequently more is assumed.
To find out more or to use the CALM calculator click here.
Farm Carbon Calculator
The Farm Carbon Calculator is part of the Farm Carbon Cutting Toolkit, a non-profit organisation dedicated to helping farmers and growers get to grips with carbon emissions. Jonathan Smith, an organic grower from the Isles of Scilly who runs Scilly Organics, is the lead developer. If you are interested in his account on creating the calculator; the process, thinking behind it and how it can benefit a farmer or grower, look at Out and about carbon footprinting.
The main difference between this carbon calculator and others is that it takes in to consideration carbon emissions through processing and distribution beyond the farm gates but does not take in to account land use changes. It also considers carbon emissions stored in farm vehicles, building materials and consumables whereas other tools do not.
Version 3.0 is now available and includes new features such as agro chemicals, waste and a new easier-to-use distribution section.
To find out more or to use the FCCT calculator click here.
CPLAN v0 and CPLANv2
The CPLAN calculator was designed by farmers in central Scotland for land based industries and farmers. CPLANv0 is a free online anonymous calculator while CPLANv2 is for members only. It is free to register for CPLANv2 but a small fee is charged to perform the calculation and generate the report. CPLANv0 makes more assumptions and requires less data input and does not take grasslands into account when determining nitrous oxide emissions from crops.
CPLAN v2 is the only web based model that provides the user with both the average and upper and lower estimates of their greenhouse gas budgets. It also allows the user to opt for standard or customised data; customised allows for a lot of detail while standardised makes more assumptions. For example, v2 allows the user to specify species and year of planting whereas v0 only allows the user to differentiate between broadleaf and conifers, and select age brackets.
To find out more or to use the CPLAN calculator(s) click here.
This calculator has been developed by the Low Carbon Farming Project. It claims to be different from other calculators principally through the feedback report generated which highlights areas for improvement, providing targeted, technical support. Users are encouraged to monitor their progress towards best practice in relation to low carbon farming, lowering the emissions impact of their farm, saving valuable resources and improving the overall efficiency of the farm.
The calculator does require the user to collect specific livestock data but provides a data collection sheet and instructions to help do this.
To find out more or to use the FCAT calculator click here.
Sources: Case-study comparison review by the Soil Association, and the website for each of the carbon calculators.