Environmental impact of coffee cultivation

Note

In this article/study, we calculate the CO₂ footprint of coffee using our coffee farm Santa Rita as an example, from cultivation to roasting. Santa Rita is located in the Dipilto region in northern Nicaragua and is a small farm of 4.16 hectares. The figures are based on the 2021/22 harvest and, due to the relatively low yield, represent only a snapshot. At the time of data collection, large parts of the farm were undergoing renewal, resulting in a low harvest volume and, consequently, a high CO₂ footprint per kilogram. However, the study also primarily establishes a framework for calculating the footprint of other coffee farms and the footprint along the coffee chain.

The study summarizes essential aspects of our work in the Kaffeemacher:innen research and sustainability department. This area is headed by environmental engineer Tobias Milz.

Abstract

The CO₂ balance for the 2021/2022 harvest was determined using the Cool Farm Tool. This involves a 4.16-hectare farm in Dipilto, Nicaragua, operated by Kaffeemacher in partnership with Bridazul. The calculation is based on a yield of 268.26 kilograms of exportable green coffee. The coffee farm was acquired by Kaffeemacher GmbH in 2017 and has been undergoing renovation since then. During the period under review, less than half of the plants were in production (3665 in production; 5363 not in production). Fertilizers and pesticides were applied to the entire farm, not just the productive areas. We therefore expect a reduced footprint per kilogram in the coming years, both through improvements in practice and through increased yields as more trees come into production.

The practice at Santa Rita is that, apart from harvesting and the initial cleaning of the coffee cherries, no further processing steps are carried out on the farm. The harvested cherries are transported to the partner farm "El Arbol," located 7.4 kilometers away, for further processing. The subsequent steps then take place at the Bridazul dry mill in Dipilto, a further 23.3 kilometers away. The green coffee is shipped together with other coffees from the Dipilto region and reaches our roastery in Basel, where it is roasted and packaged.

The export-ready green coffee has a CO₂ footprint of 1.57 kilograms of CO₂ equivalent per kilogram, which corresponds to 101.15 kilograms of CO₂ equivalent per hectare and a total of 430.79 kilograms of CO₂ equivalent for the entire harvest.

We deliberately chose not to include the farm's existing trees and unused areas as a carbon sink in the calculation. We cannot guarantee that the trees will remain standing for the next 50 to 100 years in the event of forest fires or the sale of the farm. If we were to take these into account, approximately 1000 kg of CO₂ could be credited to the farm.

Distribution of emissions for roasted coffee from Santa Rita

In total, our calculation of transport and the footprint of the Kaffeemacher roastery in Basel in 2022 results in a CO₂ equivalent of 2.96 kilograms of CO₂ equivalent per kilogram of roasted coffee, assuming a roasting loss of 15%. The distribution of this footprint is as follows: The largest share, namely just under 1.85 kilograms of CO₂ equivalent per kilogram, is attributed to the roasted coffee, which corresponds to approximately 62.5%. The transport share is 22.5%, which corresponds to 0.66 kilograms of CO₂ equivalent per kilogram of roasted coffee. The roastery causes a further 0.45 kilograms of CO₂ equivalent per kilogram, accounting for approximately 15%. The share of coffee from our own farm processed in the roastery is about 2%.

Introduction

This study is an environmental impact assessment of the Kaffeemacher's Santa Rita farm, which was prepared using the Cool Farm Tool.

Farm

The farm is Santa Rita, with its associated Mil Variedades area, which has been owned by Kaffeemacher GmbH since 2017. The farm is located in northern Nicaragua, in the Department of Nueva Segovia in the municipality of Dipilto. The farm covers 4.16 ha and, at the time of data collection, had 9028 coffee plants, of which 3665 were in production. The farm has been undergoing renovation since it was taken over by Kaffeemacher GmbH. Many plants were removed, and new varieties were planted. As a rule, plants bear their first cherries after three years. This explains why only a portion of the plants are bearing fruit.

The cultivation method is agroforestry with manual harvesting. Until now, synthetic fertilizers and pesticides have had to be used for protection against coffee berry borer infestation or rust, and to promote plant growth. The goal is to gradually phase these out, replacing them with "biologicals" and self-produced compost. As a next step, Bridazul and Kaffeemacher are working on producing high-quality compost centrally and efficiently from coffee production by-products.

The farm is located 7.4 km from El Arbol, another farm operated by Bridazul. Bridazul are the partners of Kaffeemacher who operate the farm on-site. Except for an initial selection of the cherries, all essential post-harvest processes take place at El Arbol rather than at Finca Santa Rita.

For further fermentation and drying of the cherries, the coffee is taken to the Bridazul dry mill in Ocotal, which is 23.3 km away. The offices and laboratory are also located here. Before the coffee is exported, it is hulled at Edman Café in the same town and packed in 30 kg jute bags with an inner liner.

Limitations of the analysis

As a rule, only on-farm work is considered in environmental impact assessments. Since the farm would not function without partners, work outside the farm must also be included. Therefore, various factors such as energy consumption in the office and during processing must be proportionally allocated to the farm's coffees.

The Cool Farm Tool does not account for waste or packaging materials. This means that jute bags, liners, and other packaging, whether for the coffee itself or its production, are not considered.

The varying resource situations in different countries are also not included in the calculation. Therefore, the calculation of energy consumption is based solely on a global average for electricity usage.

Data uncertainties

A major criticism of environmental impact assessments (EIAs) is that uncertainties are often not or only barely addressed in communication<1>. However, every environmental analysis must deal with uncertainties and assumptions. It is therefore very important to disclose them. Below you will find the uncertainties assessed and contextualized by category.

We have rated the uncertainties according to the German school grading system. From 1 for very low uncertainty to 6 for no certainty.

Data collection

Most of the data were collected on-site in April 2022. All ecological, economic, and social factors were surveyed using a questionnaire specifically developed for coffee farms, which includes over 200 questions. Further details for the calculation were provided by Bridazul. Bridazul invoices Kaffeemacher for all work carried out at Santa Rita, including the materials used. Therefore, it can be tracked very precisely what was used, how much, and when.

In addition, Kaffeemacher is the only buyer of the coffee from the farm, so it can be stated exactly which processing method was applied to which coffee. For the calculation, however, an average must be assumed, which affects water and energy consumption.

Result

The calculation shows that the total footprint of the 21/22 harvest is 420.78 kg of CO₂ equivalents. This corresponds to 101.15 kg CO2e per hectare and 1.57 kg CO2e per kilogram of green coffee.

Energy use (electricity)

At 33.2%, energy emissions for processing are the largest factor. This is due to the fact that these are heavily processed coffees.

The coffees undergo a controlled fermentation process at Bridazul, which also provides a cold storage facility to ensure a controlled environment. This results in high energy consumption, even though the process only runs for one month a year. Assuming electricity costs of $0.05 per pound of green coffee, this corresponds to a consumption of 126.56 kWh for our coffees.

Fertilizer

On many farms where plants are exposed to full sun, fertilizers account for a large proportion of emissions (> 80%). This already becomes clear when looking at the origins of the assumptions in studies used, for example, for Ecoinvent. Ecoinvent is a common environmental database. However, Ecoinvent does not maintain a dataset for coffee from Nicaragua, but it does for Honduras. Due to the farm's geographical proximity, this dataset can be used. This assumes an application rate for NPK fertilizers of 343-223-221 kg/ha, resulting in emissions of 10.11 kg CO2e / kg green coffee.

At Santa Rita, an application of 6.56-5.80-26.67 NPK fertilizer occurs. The organic fertilizers are included here, as is the fertilizer for plants that are still growing and not yet yielding.

The high fertilizer application rate in the Honduras dataset achieves a yield of 1340 kg / ha. By comparison, the yield at Santa Rita is 101.15 kg/ha. The yield is therefore 13.25 times higher. However, the factor for nitrogen (N) fertilizer application is increased by a factor of 52.29, and for phosphorus by 38.45; only for potassium is the factor smaller than the yield factor (8.29). Nevertheless, the yield is expected to increase in the coming years as more plants transition into the production phase. (As a rule, coffee plants start bearing cherries after three to four years.)

Transport

At 14.8%, transport is a significant factor. This is primarily because workers and all resources must be transported to the farm, as no one lives on the farm except for two employees. However, transport does not include the transport of coffee to the port. We calculate this separately, along with shipping and transport within the EU.

Roads in remote regions of Nicaragua cannot be compared to roads in Switzerland, and the extra effort caused by unevenness or lack of paving must be factored in.

Discussion

Comparison of green coffee emission data

Existing environmental data for coffee vary greatly or are unavailable. Data in environmental databases such as Ecoinvent aim to achieve a high degree of general validity. Therefore, the focus is on producing countries like Brazil, Vietnam, Colombia, Indonesia, and Honduras, which account for 85% of the global supply. The remaining 15% are distributed among another 55 producing countries and therefore receive less attention in large-scale studies.<2>

For this reason, Ecoinvent also does not maintain data for Nicaragua. Since Honduras is a neighboring country to Nicaragua, uses similar agricultural practices, and coffee cultivation in Honduras resembles the cultivation structures in Nicaragua, a comparison is appropriate. The Honduras dataset shows 10.11 kg CO2e / kg green coffee<3>. The dataset from Carbon Cloud, a freely accessible database focused on food, indicates 4.0 kg CO2e/kg green coffee<4> for coffee from Nicaragua. A study by Caravela Coffee, which also takes into account carbon storage by the agroforestry system, arrives at approximately -12.7 kg CO2e/kg green coffee<5>. The farm under consideration is therefore in the midfield of these values. If land use change were to be considered at Santa Rita, approximately 4 kg CO2e/kg green coffee would have been stored at Santa Rita. In this case, only the area no longer managed as forest would be considered, in addition to new trees and shrubs such as bananas and Inga.