Will Coffee Survive Climate Change?

If you didn’t know better, as you walked the dirt path onto Naygney Assu’s coffee farm, you’d think it had been abandoned. His farm is located on an otherwise serene hillside in Espirito Santo state in eastern Brazil in the heart of the equatorially centered coffee belt. The typically lush Robusta coffee plants Naygney has grown for years, are now bare sticks rattling with a crown of dry curled leaves. Naygney and the neighboring farmers haven’t seen any rain in over three months and a review of longer term trends of the region have revealed a steady decrease in rainfall for the past several years. In fact, eighteen years ago, the area typically experienced 51 inches of rainfall while 2016 brought just 15.7 inches of rainfall. Wells are dry and debts are rising. Naygney has already lost ninety percent of his coffee crop this year and while he can do nothing but wait for rain, Naygney’s hopes for a future in coffee farming are lost. A closer look at the science of coffee farming today paints a clear picture that the changing climate is behind many of problems facing coffee production worldwide and that things are likely to continue to deteriorate.

In order to understand the future of coffee, a little knowledge of the past and current state of coffee production is necessary. One of the most important qualities of coffee farming, as it relates to climate change, is that coffee plants experience optimum growth in a relatively narrow set of environmental conditions- the plant must be warm, but not too warm, and have a predictable wet and dry season. Optimal conditions are found in about 70 countries along the equator typically in tropical highlands. Among hundreds of species and thousands of varieties, there are two main species of coffee grown for global distribution; Robusta (Coffea canephora) and Arabica (Coffea robusta). Beans from Robusta plants are often considered a lower quality because of their low acidity, high bitterness, and generally unrefined “burnt rubber” flavor. Yet, Robusta contributes to about 30% of global production and is used for freeze-dried coffee and coffee blends. Robusta differs dramatically from Arabica because the Robusta plant can grow at lower elevations, in warmer temperatures, and can often produce coffee berries even with sporadic rainfall events.

Arabica coffee makes up the other 70% of the global production and is known to produce a higher quality bean used in specialty coffee drinks. Arabica’s optimal growing temperatures are between 64° and 70° F in cooler, shaded environments. During critical growing periods, even a half a degree outside of this range can cause stunted growth, prevent flowering, or cause the drop of existing flowers; greatly impacting coffee bean quality and quantity. These narrow environmental conditions are often met in tropical highlands thus Arabica is often grown in forests on mountain sides. Traditionally, coffee plants are established within existing forests and harvested by hand. However, today coffee cultivation practices vary widely and coffee farming practices also include clear cutting in order to produce large monocrop field and include the implementation of large agricultural machinery useful for quick and cheap harvesting.

Oftentimes when monocrop fields are planted quantity of bean is the goal. While this method can reduce the cost of labor for harvesting and allows more coffee plants to be grown in the same amount of space than a shade grown coffee farm, large monocrop fields of coffee heavily impacts the pollinator-plant relationship. When large swaths of land are devoted to producing one crop like coffee, the crop will all flower during a short concise window. During flowering, pollen and nectar is abundant but outside of the flowering period, the monocrop field is like a wasteland providing no food until the next flowering cycle. In a botanically diverse forest, pollinators are more abundant and diverse because they have access to more abundant and diverse plants flowering throughout the year providing the food and other necessary resources. Study after study shows that when pollinators are reduced or absent, the coffee yield is also impacted in quality and quantity. One study showed that bee species diversity increased fruit set in coffee: in Indonesia, coffee plants visited by three species of bees had 60% fruit set and those with 20 species or more had 90% fruit set.

Coffee plants grown in shaded forests also have been shown to suffer less from two of the most common ailments facing coffee today as a result of increased temperatures brought on by climate change - coffee rust fungus and coffee berry borer. Global warming has expanded the habitat and thus the range and damage of the coffee berry borer, a predator which infests coffee beans. This pest is placing additional stresses on all coffee crops, as is coffee rust, a devastating fungus which attacks the coffee plant through its open stomata (pores plants breathe through) that previously did not survive the cool mountain weather. Costa Rica, India, and Ethiopia, three of the top fifteen coffee-producing nations in the world, have all seen a dramatic decline in yields mainly attributed to secondary problems related to climate change. Shaded coffee farms have been shown to provide some protection from the coffee berry borer and coffee rust fungus and can be partially explained by the widely accepted ecological concept which maintains that diversity creates ecological stability. In other words, the more biodiversity a system is, the healthier the ecological workings and environment. Shade grown coffee farms with many species of plants supporting a diverse fauna including birds, lizards, and arthropods which form a complex and dynamic food web which often work to the farmer’s advantage. In addition to the pollinator services discussed above, the diversity of species in shade grown systems provides additional ecosystem services. For example, in a study conducted in Jamaica where birds were excluded from coffee plants researchers noted a 70% increase in proportion of coffee berries infested with the coffee berry borer. The biological control or ecosystem service being conducted by these birds was estimated to be worth about $75 per hectare in 2005, averaging $1004 per farm at a time when $3000 was about equal to the average national income at the time.

Higher temperatures, long droughts punctuated by intense rainfall, reduced annual rainfall, reduced diversity and abundance of pollinators, and more resilient pests and plant diseases—all of which are associated with climate change—have reduced coffee supplies dramatically in recent years (Figure 1).

What is more important to consider than the differences in ecosystem services provided by shade grown farming methods in comparison to a large monocrop field, is the biggest factor expected to change with increasing temperatures- suitable land area. In today’s changing climate, land which meets coffee’s specific environmental needs is shrinking. In an attempt to better understand how climate change would affect the suitable habitat for coffee farming, in 2016 Conservation International (CI) used trends in climate change and supply and demand to model the possible futures of coffee to the year 2050. Potential changes in land use, climate, and human values will impact the future of coffee and the future of many ecosystem services.

The first component CI explored for the coffee and climate model was the dimensions of future supply and demand. CI used trends from 1990 to 2010 reported by the International Coffee Organization to determine a Low Consumption (LC) scenario and a High Consumption

(HC) scenario. The HC scenario assumes that traditionally tea-drinking cultures such as China and India as well as in Sub Saharan Africa will experience great growth of coffee consumption. CI assumes the HC scenario is more likely and this is consistent with recent moves by coffee giants such as Starbucks which has been making huge efforts to influence culture in China and India with the opening of several mega Starbucks stores in strategically located areas. These strategic plans aim to integrate coffee into urban culture in the hopes of creating massive new markets for their products.

In the Low Consumption (LC) scenario, Europe, North America, and Latin America continue to dominate the largest proportion of coffee consumption, while traditionally coffee drinking regions don’t substantially change their coffee consumption. It is also important to note that in this LC scenario, because Europe, North America, and Latin America are traditional coffee-drinking cultures, they are considered to be near saturated and don’t see major growth in cups of coffee per capita thus the scenario is considered low consumption overall. The saturation assumption of existing coffee drinking cultures is consistent with a poll conducted by Gallup in 2015. The poll reported coffee consumption in the United States has not changed much from previous polls in 2012 or 1999. Each poll showed that about 64% of Americans consume at least one cup of coffee a day, averaging of 2.7 cups of coffee consumed a day among drinkers.

After devising potential supply and demand components, CI then introduced the complexity of potential coffee yield as it relates to the pressures of climate change. Similar to the consumption scenario, CI created a low yield (LY) and high yield (HY) scenario. In the low yield scenario, the effects of climate change are left unchecked. As a result, coffee bean yield slows by 2030, stagnates in 2040, and decreases in 2050. In the high yield scenario, it is assumed agronomists and geneticists will be able to provide solutions to help negate the impact of climate change by moving the crop into more favorable areas, irrigating their fields, and developing a coffee plant which is more resistant to the stresses of climate change including higher temperatures, erratic or decreased rainfall, and increased presence of the coffee berry borer.

Next the study combined the consumption factors and yield factors to produce four scenarios as they related to the spatial footprint needed to address consumption and yield from 2000 to 2050. In the low consumption, high yield (LCHY) scenario, the spatial footprint required to meet global coffee demand would remain relatively unchanged. In the low consumption, low yield scenario (LCLY) the spatial footprint required to meet demand would increase somewhat from what it is today. But in both high consumption scenarios (HCHY, HCLY) significant increases in spatial footprint would be required. For example, in the worst-case scenario, high consumption, low yield (HCLY) demand for coffee would be growing rapidly but the effects of climate change would create a shortage of coffee. Thus about 600,000 hectares would be needed per year by 2050 to meet demand. For reference Costa Rica has about 150,000 hectares of plantations as of 2016.

In order to understand what these numbers meant in the global context, CI analyzed where existing coffee habitat existed and how much was currently being used to farm coffee. Their results showed that in 2010 across the globe no region was using more than 20% of the suitable coffee growing area for either Robusta or Arabica. In fact, most regions were using well under 10% of the suitable coffee growing area. From here CI used climate models to project where and how much land would be suitable for coffee production in 2050. Among other things, this model excluded areas which would become too hot and dry for coffee production and included some areas further up the mountains which would become warmer offering perfect coffee farming habitat. The results showed that the overall area suitable for coffee production would be cut in half! A nearly 20% increase in unsuitable habitat from predictions in 2013 evaluating the same thing.

From here CI questioned what this would mean for the worst-case scenario, high consumption-low yield (HCLY) in order to project how much of the new suitable land would be needed to meet demand in 2050. The results showed that by 2050 under the HCLY South Asia would max out use of its coffee suitable habitat, however the rest of the world would use less than 30% of their suitable coffee habitat. For some this may sound like good news. Based on CI’s models, the year 2050 will provide ample space for coffee farming. However, there is always a catch. The report found that over 60% of the land which would be suitable for coffee farming in 2050 is currently forested (Figure 2). And in most cases 5-20% of the newly suitable land is in conservation areas. The superabundance of suitable coffee growing areas is surprising to many people, this does not mean, however, that there will not be large scale displacement of coffee plantations over the next 30 years. If plant geneticists are unable to breed to coffee varieties adapted to warmer and dryer conditions or if plantation managers fail to develop cultural practices which mitigate the impacts of climate change, farmers will be forced to migrate their plantations to cooler and more humid landscapes. This shift may lead to significant deforestation which in itself would contribute to the release of greenhouse gases further exacerbating the effects of climate change.

Several reports published in the last two years have confirmed Naygney’s fears; hotter weather and changes in rainfall patterns are fueling conditions which are edging him out of the coffee growing business. And although coffee will survive climate change, at least until 2050, it will be important for consumers to learn about the challenges faced by coffee farmers and their communities in order to support businesses and governments which take action to protect forests from deforestation and help famers build capacity to adapt to climate change. Potential changes in land use, climate, and human values will impact the future of coffee and the future of many ecosystem services.

References:

Christian Bunn, Peter Läderach, Oriana Ovalle Rivera, & Dieter Kirschke. (2014). A bitter cup: climate

change profile of global production of Arabica and Robusta coffee. Springer, (129), 89–101.

https://doi.org/10.1007/s10584-014-1306-x

Imbach, P., Fung, E., Hannah, L., Navarro-Racines, C. E., Roubik, D. W., Ricketts, T. H., … Roehrdanz, P.

R. (2017). Coupling of pollination services and coffee suitability under climate change.

Proceedings of the National Academy of Sciences, 114(39), 10438–10442.

https://doi.org/10.1073/pnas.1617940114

Lulu Garcia-Navarro. (2016, October 12). Coffee And Climate Change: In Brazil, A Disaster Is Brewing.

Retrieved December 18, 2017, from

https://www.npr.org/sections/thesalt/2016/10/12/497578413/coffee-and-climate-change-inbrazil-

a-disaster-is-brewing

Lydia Saad. (2015). Americans’ Coffee Consumption Is Steady, Few Want to Cut Back (Well-Being).

Gallup, inc. Retrieved from http://news.gallup.com/poll/184388/americans-coffee-

consumptionsteady-few-cut-back.aspx

Robert Rice, & Mauricio Bedoya. (2010). The Ecological Benefits of Shade-Grown Coffee: The Case for

Going Bird Friendly. Smithsonian Migratory Bird Center. Retrieved from

https://nationalzoo.si.edu/scbi/migratorybirds/coffee/bird_friendly/ecological-benefits-ofshade-

grown-coffee.cfm

Takahashi, R., & Todo, Y. (2017). Coffee Certification and Forest Quality: Evidence from a Wild Coffee

Forest in Ethiopia. World Development, 92(Supplement C), 158–166.

https://doi.org/10.1016/j.worlddev.2016.12.001

Timothy J Killeen, & Grady Harper. (2016). Coffee in the 21st Century: Will Climate Change and

Increased Demand Lead to New Deforestation? Conservation International. Retrieved from

https://www.conservation.org/publications/Documents/CI-Coffee-Report.pdf