Who this is for
Anyone reading completed carbon assessments who needs to see farms against each other, or one farm against its own earlier years — checking why a farm looks like an outlier, or working out what sits behind a difference in footprint.
Before you start
Only completed assessments can be compared, and an assessment still in progress is not offered as an option for comparison.
You can put between two and four assessments in a comparison, and assessments also have to be comparable with each other, so a comparison cannot mix assessment types (i.e Beef carbon with Dairy carbon or Dairy carbon with Dairy animal welfare).
Steps
The assessment list and Farm Emissions both start the same comparison. Use whichever you are already on.
From Assessment Management
- In the left-hand menu, select Farm Data, then Assessments. Assessment Management opens on the Data Collection tab, listing every farm's assessments by year.
- Narrow the list if you need to. Search farms, Filters and Columns all work here.
- Tick the checkbox at the left of each assessment you want to compare. A count appears next to Clear selection.
- Select Compare. The button carries the number of assessments you have selected.
From Farm Emissions
- In the left-hand menu, select Measurement, then Farm Emissions. For finding your way around this screen, see Read the results of a dairy carbon assessment.
- Tick the checkbox at the left of each farm you want to compare.
- Select Compare results, which appears as a bar above the table once you have made a selection. It carries the number of assessments you have selected.
How to confirm it worked
The comparison opens on Data inputs, with one column for each assessment. Each column is headed by the farm name, the farm code and the reporting year.
Check the year at the top of each column before you read anything else. The same farm can appear in a comparison more than once, one column per year, and the columns are otherwise near-identical.
Compare one farm across years
Open the farm's detail page and find Previous results. Tick the assessments you want, then select Compare. What opens is the same comparison described below.
Reading the comparison
The comparison has two tabs.
Data inputs
Data inputs puts the figures the assessments were built from side by side, grouped into sections — survey, herd composition, milk production, feed purchases, grazing and intake, fertiliser, and manure. This is the tab to use when a result looks wrong and you want to know which input explains it.
Results and ratios
Results & ratios covers what the assessments produced. A chart, Allocated emissions by category, opens the tab with a bar per assessment for each emission source, and a Basis toggle switching between Footprint and Absolute.
Below the chart, the same side-by-side table returns with the result figures, again in sections: headline, intensity and ratios, productivity, lactating cow ratios, footprint by category, and emission share.
For what any single figure covers and the units it uses, see Dairy farm metrics.
Arrows, shading and gaps
An arrow next to a figure tells you whether that assessment is the higher or the lower of the ones being compared. It is a comparison between the columns on screen, not a judgement against a benchmark.
On the emissions figures — the carbon footprint, total emissions, emissions per animal and the footprint split by category — the cell is shaded as well, green on the lower figure and red on the higher. Rows where higher is not straightforwardly worse, such as an emission share, get the arrow without the shading.
Where the figures are identical across every column, no arrow appears. A dash means that assessment has no value for that row, which is worth noticing before you read anything into a difference.
Changing what you are comparing
Select the × at the top of a column to drop that assessment out of the comparison. Select Back to return to the list you started from and choose a different set.