If you are fond of the little black boy and concerned about the environment, you have probably asked yourself this question. A 2013 study wanted to estimate the ecological impact of coffee production1. It has been evaluated at 4.98 kg EqCO2 per kg of coffee from Costa Rica, of which 3.05 kg EqCO2 / kg related to roasting and distribution in Europe and 1.93 kg for transport and production. These results can of course vary depending on where the coffee is grown and where it is consumed. But they have the merit of drawing a trend. Knowing that a coffee requires on average 7g of powder, the imprint per small black is therefore 0.035 kg EqCO2.
The ecological impact of coffee production according to its preparation method
Roland Hischier from the Swiss Federal Laboratory for Materials Testing and Research (Empa), wanted to go further in this analysis. He assessed the overall ecological impact of coffee according to the method of preparation2. He analyzed the effects of the origin of the coffee and the method used (coffee in capsules, Italian coffee maker, filter coffee, soluble coffee) on the environmental footprint. According to this expert, the determining criterion is not the method of preparation. This is the method of cultivation (including the production of fertilizers). It could influence the overall impact from 1 to 70%, 55% on average according to the Öko institute in Germany. This result therefore justifies all the more to favor responsible sectors. Regarding the method of brewing coffee, the choice of coffee machine represents around 25% of the environmental footprint, but there is no objective and exhaustive method of quantifying the impact. The most economical solution is to use an Italian-style coffee maker or the traditional filter coffee maker (or soluble coffee, but less interesting for health because of its manufacturing method, concentrating the acrylamide contents). Another important point: on condition that you do not leave it plugged in when it is not in use. The use of a capsule certainly has the advantage of limiting the amount of coffee strictly necessary (around 7g / cup) but it remains the most impactful system.
Why donate pesticides
Regarding the pesticide content in coffee, there is little data on the subject. It seems that the residual content is low, apart from a few traces of lindane and chloropyrifos in green coffee. A Japanese study that analyzed 1866 samples concluded that “only” 0.3% had levels above the permitted limit (especially DDT) and that roasting completely eliminated them.3. This is confirmed by studies evaluating the impact of roasting on residual values of pesticides4. The use of gas (methyl bromide, basamid) to preserve the coffee once harvested appears to be the main source of contamination. Concentrations of pesticides in the hessian of the bags were found in amounts 100 times greater than in green coffee. One of the main risks of health contamination by coffee remains mycotoxins, in particular ochratoxin A (OTA) produced by Aspergillus and Penicillium depending on storage conditions. The highest rates were observed in unwashed Robusta and Arabica coffees from African countries (58.3% of samples and Asia (11.1%).
The risks of PAH contamination of coffee
Another important point to consider regarding the risks of contamination of coffee is its content of polycyclic aromatic hydrocarbons (PAHs), including benzo[a]carcinogenic pyrene. Coffee can contain up to 13 different PAHs5. They can come either from contamination during drying, in particular on roadsides in contact with car exhaust gases, or from roasting. Duration and temperature are therefore decisive6. When the coffee undergoes a dark roasting or even burnt, the benzo contents[a]pyrene may exceed the maximum recommended daily intakeseven. So the best advice I can offer you is to discover a roaster near home, who is knowledgeable about his profession and the origins of the coffee he uses (including the duration and storage conditions), mastering the roasting process. It is by talking to him that you will certainly have the best answers to your questions. The principle of trust therefore prevails!
What coffee consumption in the future?
The real question to ask when it comes to coffee is how long are we going to be able to keep drinking it? There are more than 80 varieties of coffee (Typica, Maragogype, Bourbon, Blue Mountain or Mundo Novo, etc.), arabica is the most consumed in the world (market of 16 billion dollars) but also the most threatened. According to some experts, coffee from wild harvest could disappear by 2080 due to a fungus (causing orange rust), but especially because of global warming and deforestation. According to a January 2019 study on 124 varieties of wild coffees present in several African forests, 75 are directly threatened, including 13 critically endangered.8. In Tanzania, each degree of temperature rise would generate a loss of about 137 kg of coffee per year per hectare. Productivity has already fallen by 50% for 50 years in this country. A study published in 2017 estimates the drop in global production from 73 to 88% in 2050 if we reach global warming of 2 ° C. Robusta, as its name suggests, resists better but is less popular with amateurs today. Perhaps we have to accept that this will be the benchmark coffee of tomorrow … In addition, half of the coffee consumed in the world is already cultivated industrially by putting the coffee in full sun, in Brazil and Africa in particular. However, such exposure, associated with global warming, requires the use of large quantities of pesticides. The development of agroecology would, however, make it possible to cultivate coffee trees in the shade, as was the case historically, in particular by crossing resistant wild varieties and crops. Mexico, for example, is developing its research in this direction.
(1) [PDF] Carbon footprint in the coffee supply chain: the case of Costa Rican coffee | Semantic Scholar https://www.semanticscholar.org/paper/Carbon-Footprint-across-the-Coffee-Supply-Chain%3A-of-Bernard-Killian/38fb5407ae59ae2cea459ca97bb6d3daff52e431 (accessed December 15, 2019).
(2) The eco-assessment of coffee capsules under the microscope: It is the coffee that is decisive https://www.admin.ch/gov/fr/start/dokumentation/medienmitteilungen.msg-id-39078.html (accessed Dec 15 , 2019).
(3) Durand, N .; Gueule, D .; Fourny, G. Contaminants in coffee. Agriculture Notebooks 2012. https://doi.org/ Contaminants in coffee. Durand Noël, Gueule Dominique, Fourny Gérard. 2012. Cahiers Agricultures, 21 (2-3): 192-196.http://dx.doi.org/10.1684/agr.2012.0551
(4) Sakamoto, K .; Nishizawa, H .; Manabe, N. Behavior of pesticides in coffee beans during the roasting process. Shokuhin Eiseigaku Zasshi 2012, 53 (5), 233-236. https://doi.org/10.3358/shokueishi.53.233.
(5) Orecchio, S .; Ciotti, vice-president; Culotta, L. Polycyclic Aromatic Hydrocarbons (PAHs) in Coffee Brewing Samples: GC-MS Analysis Method, Profile, Levels and Sources. Food Chem. Toxicol. 2009, 47 (4), 819-826. https://doi.org/10.1016/j.fct.2009.01.011.
(6) Houessou, JK; Maloug, S .; Leveque, A.-S .; Delteil, C .; Heyd, B .; Camel, V. Effect of Roasting Conditions on Polycyclic Aromatic Hydrocarbon Content in Ground Arabica Coffee and Brew Coffee. J. Agric. Food Chem. 2007, 55 (23), 9719–9726. https://doi.org/10.1021/jf071745s.
(seven) Houessou, JK Polycyclic aromatic hydrocarbons in coffee: development of analytical methods and study of the roasting process. 272.
(8) High extinction risk for wild coffee species and implications for the sustainability of the coffee sector | Science Advances https://advances.sciencemag.org/content/5/1/eaav3473 (accessed December 15, 2019).