A Caffeine Lover’s Nightmare? The Potential Impact of Climate Change on Indigenous Arabica Coffee Plants

Canada’s Morning Cup of Coffee

On October 2011, Canada’s Agri-Food Trade Services attended Vancouver’s Canadian Coffee and Tea Show, and reported that coffee is the most popular hot beverage in Canada. About 86% of adults-especially between the ages of 25 to 49-consume coffee during the morning or at breakfast time [4].

That same year, Canada was reported to import about $5 billion worth of coffee products from Brazil, Indonesia, Columbia, Ethiopia, and Vietnam. Moreover, within recent years, more Canadians have been investing in  ‘consumer conscious’ coffee products (i.e. organic, fair-trade) and single-serve devices, estimated to be worth approximately $650 and $750 million annually respectively [4, 5].

What with its enticing aroma and earthy taste, all these numbers only mean one thing: Canada really loves its coffee!

World Coffee Production: The Arabica Coffee Bean

Chances are your delicious morning coffee is made from a blend of Coffea arabica Linné, or Arabica, beans. With over 200 varieties, Arabica coffee is the most commercially produced coffee product next to the robusta (Coffea canephora spp.) variety [8].

While indigenous Arabica varieties originate in Northeast Tropical Africa (such as parts in Yemen, Ethiopia, and Sudan), unique hybrids have also been introduced in areas of the Caribbean, Pacific, Southeast Asia, China, and Latin America [6, 7].

According to the International Coffee Organization, the global annual retail value of Arabica coffee was estimated at US $90 billion in 2011, so they don’t call it the top ‘cash crop’ for nothing! Moreover, this variety is the sole economic income for over 25 million families in 60+ nations, especially in Ethiopia, which is Africa’s main coffee producer and the 5th largest global exporter of Arabica [2, 1, 8].

However, purveyors and connoisseurs of Arabica coffee should know that the plant is sensitive to a changing climate, something we’ve been experiencing quite a bit these days.

So, what’s the big hubbub? You may ask me. I still get my morning cup of coffee! 

And I say to you: let science give you the big, heaping scoop.

Predicting the Future Distribution of Indigenous Arabica Species Using Climate Modelling

A 2012 study in PLOS ONE by Davis et al. explored the distribution of naturally occurring (indigenous) Arabica species for present day as well as the future years of 2020, 2050, and 2080 using bioclimatic modelling. This type of modelling has been used in ecological studies for over 10 years, and predicts the impact of global species distribution as a result of climate change [1].

Mapping Arabica Distribution

Davis and colleagues (2012) determined and predicted the distributions of indigenous Arabica species with the aid of physical records (i.e. literature sources, field survey data of Arabica populations in Ethiopia, and herbarium specimen collections) and computer software (i.e. Google Earth, MaxEnt, ArcGIS; Figure 1, 2A).

journal.pone.0047981.g001

This figure represents the estimated (yellow-red colours) and determined (green points) distribution of indigenous Arabica species. In this study, 713 records identified areas–or localities–where the coffee species are possibly found, yielding 349 unique localities for indigenous Arabica. As for predictions, there’s a possibility that indigenous Arabica may not be found in these yellow-red coloured areas, due to several possible factors outlined by Davis et al. (2012; i.e. niche saturation, incorrect modelling, etc.). doi:10.1371/journal.pone.0047981.g001

Using the 349 identified localities, Davis et al. (2012) also mapped different ‘thresholds of bioclimatic suitability’ for the indigenous Arabica. That is, they determined areas that the native Arabica species may possibly grow optimally (68% threshold), intermediately (95% threshold), and marginally (100% threshold) over time (Figure 2B).

journal.pone.0047981.g002-2

An identical map to Figure 1 (with green dots representing unique localities), 2B also illustrates potential areas for optimal (green), intermediate (beige), and poor (red) Arabica coffee growth. 

Using Climate Models to Investigate Future Arabica Distributions

Davis et al. (2012) observed how the unique localities will change by 2020, 2050, and 2080 under 3 different climate change scenarios (referred to as the Intergovernmental Panel on Climate Change’s emission scenarios, 11) under the Hadley Centre Coupled Model version 3 (HadCM3) climate change model [10]:

  • A1B” is a scenario of an Earth that is experiencing a rapidly growing economy, with equally distributed global use of fossil-based and non fossil energy sources and maximum energy demands [1, 11].
  • A2A” represents an Earth with increasing population, high energy requirements but slow, fragmented economic and technological growth [1, 11].
  • B2A” represents an Earth that recognizes environmental sustainability, with low energy requirements and modest, yet diverse technological change [1, 11].

With the same HadCM3 model and climate scenarios, Davis et al. (2012) also used their calculated thresholds to assess how bioclimatic suitable areas for indigenous Arabica will change by 2020, 2050, and 2080 (Figure 5), predicting possible migration patterns.

The Study’s Findings & Results: Indigenous Arabica Distribution by 2020, 2050, and 2080

Davis et al. (2012) observed that across all 3 climate change scenarios, there will be dramatic loss of localities and bioclimatic suitable growing areas for indigenous Arabica species.

Specifically, the most devastating loss will occur in A2A and A1B climate scenarios, where almost 100% of the 349 unique localities will become unsuitable for Arabica growth by 2080 (Figure 3). In contrast, the ‘best case scenario’ will be during a B2A situation, where ‘only’ 65% of the unique localities will become unsuitable for indigenous Arabica growth by 2080 (Table 1).

Furthermore, Davis et al. (2012) observed reductions in large bioclimatic suitable areas for indigenous Arabica overtime. By 2080, they observed area reductions of 38%, 56%, and 55% for scenarios B2A, A2A, A1B respectively. Furthermore, the researchers observed that Arabica growth will migrate to northward directions over time, suggesting the (limited) formation of new bioclimatic suitable space for the coffee plant (Figure 5).

Putting It All Together: What It Means to the Coffee Industry

TldrAccording to results from Davis and colleagues’ (2012) study, the population naturally occurring Coffea arabica in parts of Africa (especially Ethiopia) may be negatively affected by climate change in the future. 

If studies like Davis et al.’s (2012) are correct, climate change can negatively affect crop production of the Arabica, which can devastate the coffee industry in return. Especially for farmers in Ethiopia, Arabica is a source of economic livelihood, with production of forest and semi-forest coffee accounting for ~25% of total coffee production in the country [1].

Davis et al. (2012) does provide implications that should we care about preserving the natural growing areas of the Arabica bean, there should be development of conservation programs to protect the coffee plant.

Further studies should also delve into how climate change, in addition to other factors such as human activities (deforestation, land-use) or diseases/pests, will impact indigenous Arabica crop production and distribution. These are important factors that may not have necessarily been taken into account with David and colleagues’ study (2012).

What it Means to the Everyday Coffee Consumer

Does this mean that ‘naturally grown’ Arabica coffee beans will increase in price? Or will a cup of coffee made from 100% Arabica beans be more costly for the most avid coffee connoisseur? Should coffee purveyors be aware of the possible impending doom that is the decline of ‘naturally grown’ arabica coffee bean production?

Maybe. But let’s not draw hasty conclusions.

For the Jane and Joe that prefers the tender taste of Arabica coffee over other varieties (i.e. robusta), this study may come as unsettling. If you’re a diehard coffee drinker, then maybe this convinced you to raise an eyebrow or two about the capabilities of climate change and its impact on our global environment and our beloved coffee plants.

References
  1. Davis, A. P., Gole, T. W., Baena, S., & Moat, J. (2012). The impact of climate change on indigenous arabica coffee (Coffea arabica): predicting future trends and identifying priorities.
  2. Jaramillo, J., Muchugu, E., Vega, F. E., Davis, A., Borgemeister, C., & Chabi-Olaye, A. (2011). Some like it hot: the influence and implications of climate change on coffee berry borer (Hypothenemus hampei) and coffee production in East Africa. PLoS One6(9), e24528.
  3. Baca, M., Läderach, P., Haggar, J., Schroth, G., & Ovalle, O. (2014). An integrated framework for assessing vulnerability to climate change and developing adaptation strategies for coffee growing families in Mesoamerica. PloS one9(2), e88463.
  4. Agriculture and Agri-Food Canada. (October 2011). Coffee and Tea Industry Trends from the Canadian Coffee and Tea Show. Retrieved from http://www.agr.gc.ca/eng/industry-markets-and-trade/trade-events/post-show-reports/coffee-and-tea-industry-trends-from-the-canadian-coffee-and-tea-show/?id=1410072148362
  5. M Cardwell. (2015, March 9). Coffee Consumption Habits Continue to Shift in Canada. Retrieved from http://www.marketingmag.ca/consumer/coffee-consumption-habits-continue-to-shift-in-canada-139728
  6. Coffea arabica (Arabica coffee) (n.d.). In Kew.org. Retrieved from http://www.kew.org/science-conservation/plants-fungi/coffea-arabica-arabica-coffee
  7. Coffea arabica. (n.d.). Retrieved November 11, 2015 from Wikipedia: https://en.wikipedia.org/wiki/Coffea_arabica
  8. Pohlan, H. A. J., & Janssens, M. J. (2012). Growth and production of coffee. Soil, Plant Growth Crop Produc3, 1-11.
  9. Schmitt, B. C. (2006). Montane Rainforest With Wild Coffea Arabica in the Bonga Region (SW Ethiopia): Plant Diversity, Wild Coffee Management and Implications for Conservation. Göttingen, Germany: Cuvillier Verlag.
  10. Met Office. (n.d.). Met Office climate prediction model: HadCM3. Retrieved from http://www.metoffice.gov.uk/research/modelling-systems/unified-model/climate-models/hadcm3
  11. IPCC. (2001). Climate Change 2001: Impacts, Adaptations, and Vulnerability. Retrieved from http://www.grida.no/publications/other/ipcc_tar/

Renee has received her B.Sc. in Honours Life Sciences at McMaster University. She loves educating others about different topics in science, and has developed a passion for scientific outreach. When she’s not writing articles for Hemtecks, she’s either volunteering or checking her social media accounts every 20 minutes. Along with Tiffany and Adelle, she also facilitates the blog’s Facebook page. 

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