How We Calculate the Carbon Footprint of a Coffee Seedling
When Taiwan talks about agricultural carbon footprints, the count usually starts in the field. But a coffee tree has already spent months in a nursery before it is planted: the substrate, containers, water, lighting and fertiliser it used are all part of its footprint. This "starting footprint" has been a blank in Taiwan's data. At the Net-Zero Resilience Research Centre container lab at Dharma Drum Institute of Liberal Arts, the association is filling that blank this year. Coffee seedlings are the first exercise.
What we count
The scope runs from a seed to a seedling ready to leave the nursery. Everything that enters the nursery during that time enters the calculation:
- the seed or tissue-culture plantlet itself
- growing substrate and containers
- irrigation water
- electricity for lighting and irrigation equipment
- fertiliser and consumables
- transport up to the nursery gate
What happens after the seedling leaves is out of scope. Cutting it this way means that whichever field the seedling ends up in, the field stage can simply be added to this number instead of recalculated.
How we count
The method follows the international standard for product carbon footprints: every input needs a quantity, a source and an emission factor, and nothing goes into the table without all three. The container lab was designed so that these quantities can actually be measured. Perovskite solar panels supply the lighting and equipment, an AIoT irrigation system logs every watering, and biochar buried in the facility stores carbon. Electricity and water are read from meters, not estimated.
The same procedure is applied to tree, vegetable and coffee seedlings so the three can be compared.
Why count at all
First, to fill the data gap. Taiwan currently has no citable starting footprint for the seedling stage, so crop footprints either ignore it or borrow foreign figures.
Second, so members get seedlings with a number attached. Association members will be able to obtain tree, vegetable and coffee seedlings with a carbon footprint that can be used directly in corporate inventories and ESG disclosures.
Third, to move towards product category rules. Once the calculation is complete, the association plans to submit seedling product category rules (PCR) to the Ministry of Environment in 2027, with the association as co-author. With a rule in place, any nursery can calculate the same way, and the numbers become comparable.
Why coffee first
Under the mountain-to-sea natural carbon sink programme, the association works with the Mawudu Coffee Cooperative, using its plantation as a demonstration site for regenerative farming and validating biochar in a real production system. A coffee seedling raised in the lab, carrying its starting footprint into the cooperative's plantation, with the field stage added on, is a complete footprint chain. It is the crop we are most confident of walking end to end.
Timeline and results
The container lab was completed in June this year. Breeding tests and the seedling footprint calculation are scheduled to finish in December. When the results are in, the figures, the method and the data sources will be published together on this site's carbon disclosure platform, not just a headline total.
Until then this article will not contain a single number. We would rather be slow than publish a figure without a source.