Environmental impact of coffee cultivation

Note

In this article/study, we calculate the CO₂ footprint of coffee using our Santa Rita coffee farm 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 ha. The figures are based on the 2021/22 harvest and are only a snapshot due to the relatively small yield. At the time of data collection, large parts of the farm were undergoing renewal, resulting in a low harvest volume and thus a high CO₂ footprint per kilogram. However, the study also primarily outlines a framework for calculating the footprint of other coffee farms and along the coffee chain.

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

Abstract

The CO₂ balance for the 2021/2022 harvest was determined using the Cool Farm Tool. It concerns 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 under 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 high-yield areas. Therefore, we expect a reduced footprint per kilogram in the coming years, partly through improvements in practice and partly through increased yields as more trees come into production.

The practice at Santa Rita is that no further processing steps are carried out on the farm except for harvesting and the initial cleaning of the coffee cherries. The harvested cherries are transported to the partner farm "El Arbol", located 7.4 kilometers away, for further processing. The next steps then take place in Bridazul's Dry Mill in Dipilto, which is another 23.3 kilometers away. The green coffee, along with other coffees from the Dipilto region, is shipped to 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 consciously decided not to include the existing trees and unused areas of the farm as carbon sinks in the calculation. We cannot guarantee that the trees will remain standing for the next 50 to 100 years, should there be forest fires or the sale of the farm. If we were to consider these, approximately 1000 kg of CO₂ could be credited to the farm.

Distribution of emissions from Santa Rita roasted coffee

Overall, 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 part, nearly 1.85 kilograms of CO₂ equivalent per kilogram, is attributable to roasted coffee, accounting for 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 an additional 0.45 kilograms of CO₂ equivalent per kilogram, which is about 15%. The share of coffee from our own farm processed in the roastery is about 2%

Introduction

The study is an environmental impact assessment of the Santa Rita farm of Kaffeemacher, created with the help of the Cool Farm Tool.

Farm

The farm is Santa Rita, including the associated area Mil Varidades, 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 under renovation since its acquisition by Kaffeemacher GmbH. Many plants were removed, and new varieties were planted. Typically, plants bear their first cherries after three years. This explains why only a portion of the plants bear fruit.

The cultivation method is agroforestry with manual harvesting. So far, pesticides have been necessary to protect against Broca infestation or Roya, and synthetic fertilizers and pesticides have been used to promote plant growth. The goal is to gradually eliminate their use. They are to be replaced by "biologicals" and self-produced compost. In the next step, Bridazul and Kaffeemacher are working to centralize and efficiently produce high-quality compost from coffee production by-products.

The farm is located 7.4 km from El Arbol, another farm operated by Bridazul. Bridazul are Kaffeemacher's partners who operate the farm on site. With the exception of an initial selection of cherries, all essential post-harvest processes do not take place at Finca Santa Rita, but at El Arbol.

For further fermentation and drying of the cherries, the coffee is brought to Bridazul's Dry Mill in Ocotal, located 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 inliner.

Limits of the Analysis

Typically, environmental impact assessments only consider activities on the farm. However, since the farm would not function without partners, activities 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 take into account waste or packaging materials. This means that jute bags, liners, and other packaging used either for the coffee or for production are not considered.

The differing 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 use.

Uncertainties in the Data

A major criticism of Environmental Impact Analyses (EIAs) is that uncertainties receive little to no attention in communication <1>. However, every environmental analysis must deal with uncertainties and assumptions. Therefore, it is very important to identify them. Below, you will find the uncertainties rated and contextualized by category.

We rated the uncertainties according to the German grading system. From 1 (very low uncertainty) to 6 (no certainty).

Data Collection

Most of the data was collected on site in April 2022. All ecological, economic, and social factors were collected using a questionnaire specifically developed for coffee farms, comprising over 200 questions. Further details for the calculation were provided by Bridazul. Bridazul bills Kaffeemacher for all work, including materials used, carried out on Santa Rita. Therefore, it is possible to track very precisely what, how much, and when was used.

Furthermore, Kaffeemacher are the sole buyers of coffee from the farm, so it can be precisely stated which processing was applied to which coffee. However, for the calculation, 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 CO₂ equivalents. This corresponds to 101.15 kg CO2e per hectare and 1.57 kg CO2e per kilogram of green coffee.

Energy Usage (Electricity)

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

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

Fertilizer

For many farms where plants are exposed to full sun, fertilizers account for a large portion of emissions (> 80%). This becomes clear when examining the assumptions behind studies used, for example, for Ecoinvent. Ecoinvent is a widely used environmental database. However, Ecoinvent does not have a dataset for coffee from Nicaragua, but it does have one for Honduras. Due to the farm's proximity, this dataset can be used. Here, NPK fertilizer application is assumed to be 343-223-221 kg/ha, resulting in emissions of 10.11 kg CO2e / kg green coffee.

At Santa Rita, NPK fertilizer application is 6.56-5.80-26.67. Biological fertilizers are included here, as are fertilizers for plants that are still growing and not yet yielding.

The high fertilizer application in the Honduras dataset yields 1340 kg/ha. The yield at Santa Rita, in comparison, is 101.15 kg/ha. Thus, the yield is 13.25 times higher. However, the factor for nitrogen (N) fertilizer application is increased by a factor of 52.29, for phosphorus by a factor of 38.45, only for potassium is the factor smaller than the yield factor (8.29). However, it is expected that the yield will increase in the coming years as more plants enter the production phase. (Typically, coffee plants start bearing cherries after three to four years.)

Transport

Transport is a major factor at 14.8%. This is mainly due to the fact that workers and all resources have to 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 additional effort caused by unevenness or unpaved surfaces must be included.

Discussion

Comparison of Emission Data for Green Coffee

Existing environmental data for coffee varies widely or is unavailable. Data in environmental databases such as Ecoinvent aim to cover a high degree of generality. Therefore, the focus is on producing countries such as 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 does not have data for Nicaragua. Since Honduras is a neighboring country of Nicaragua and 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 Carbon Cloud dataset, a freely accessible database focused on food, shows 4.0 kg CO2e/kg green coffee <4> for coffee from Nicaragua. A study by Caravela Coffee, which also considers carbon sequestration by the agroforestry system, results in approximately -12.7 kg CO2e/kg green coffee <5>. The farm under consideration thus falls in the middle of these values. If land use change were considered at Santa Rita, approximately 4 kg CO2e/kg green coffee would have been stored at Santa Rita. This would only consider the area that is no longer managed as forest. New trees and shrubs such as bananas and Inga would also be added.