"Mountain-grown" coffee is a well-known and well-worn catch phrase, due to a long-running advertising campaign, but it also indicates the obvious: much of the world's coffee supply is indeed grown in tropical mountainous regions. The iconic image of Juan Valdez and his burro in front of a mountain, symbolizing "Cafe de Colombia," emphasizes this enduring geographical relationship in the coffee-producing South American nation of Colombia.
Yet, mountain regions are quite susceptible to regional climate variability, and recent meteorological factors have caused a reduction in the amount of coffee produced in Colombia, driving up world coffee prices. The short-term factor for this reduction in Colombia and also the coffee-growing regions of Brazil is above-average rainfall. Over the longer term, the increase in temperature over the past three decades, which reduces the range of mountainous habitats in which coffee plants thrive, is the main contributing factor.
Bloomberg News reported that heavier than normal rainfall last year reduced coffee production in Colombia (heavier rainfall could continue this year), and Nestle subsidiary Nespresso reported problems with their high-end arabica bean supply due to poor weather conditions in both Colombia and Brazil.
The New York Times, in the article, "Heat damages Colombia coffee, raising prices," provides the following information:
- "Coffee plants require the right mix of temperature, rainfall and spells of dryness for beans to ripen properly and maintain their taste. Coffee pests thrive in the warmer, wetter weather."
- "The shortage of high-end Arabica coffee beans is also being felt in New York supermarkets and Paris cafes, as customers blink at escalating prices. Purveyors fear that the Arabica coffee supply from Colombia may never rebound — that the world might, in effect, hit “peak coffee.”
- "The Colombian Coffee Growers Federation says high fertilizer prices have also dented yields. But it agrees with a 2009 report from the International Coffee Organization that concluded, “Climatic variability is the main factor responsible for changes in coffee yields all over the world.”
- "Average temperatures in Colombia’s coffee regions have risen nearly one degree in 30 years, and in some mountain areas the increase has been double that, says Cenicafé, the national coffee research center. Rain in this area was more than 25 percent above average in the last few years."
- “Half a degree can make a big difference for coffee — it is adapted to a very specific zone,” said Néstor Riaño, a specialist in agroclimatology for Cenicafé. “If temperature rises even a bit, the growth is affected, and the plagues and diseases rise.”
The two images below, generated with Tropical Rainfall Measuring Mission data, plotted with the NASA Goddard Giovanni system, and displayed in Google Earth, show the rainfall anomaly over Brazil and Colombia from September 2010 to January 2011. Green, yellow, and orange colors indicate higher-than-average rainfall during this period. The small map insets show the coffee-growing regions in each country. In both regions, the positive rainfall anomalies indicate the adverse growing conditions the farmers experienced last year.
Figure 1. Rainfall anomaly in Colombia, September 2010-January 2011. Inset map shows the main coffee-growing regions in pink and blue.
Figure 2. Rainfall anomaly in Brazil, September 2010-January 2011. The inset map shows the coffee-growing regions in southeastern Brazil.
The time series of monthly surface skin temperatures over the coffee regions of Colombia shown in Figure 3 is plotted with the Modern Era Retrospective-analysis for Research and Applications (MERRA) data set in Giovanni. The highest peaks in temperature correspond to El Niño years, but the generally increasing temperature trend is also easily discerned.
Figure 3. Time series of MERRA surface skin temperatures for the coffee-growing region of Colombia, January 1979 to December 2010. The three highest temperature peaks correspond to the 1982-1983, 1997-1998, and 2009-2010 El Niño events.
Another prime coffee region that is being affected by rising temperatures is the narrow mountain range of Costa Rica. The Seattle Times, from a city strongly connected to the rise of premium coffee and coffeehouses in the United States and around the world, described the coffee situation in Costa Rica in the article, "Climate change takes toll on coffee farmers, drinkers too." The article states the following:
- "A mile above this rural mountain town, coffee trees have produced some of the world's best arabica beans for more than a century. Now farmers are planting even higher — at nearly 7,000 feet — thanks to warmer temperatures."
- "Almost all coffee grows in the tropics, and in general, tropical species are more sensitive to climate change, said Joshua Tewksbury, the Walker professor of natural history at the University of Washington. There are more species there, they can withstand only a narrow band of temperatures, and they are not likely to adapt well to change."
- "Costa Rica has 25 percent fewer acres planted in coffee than it did a decade ago, according to the national coffee agency iCafe. Roughly 10,000 farmers have quit coffee, some converting their land to pasture for cattle or dairy businesses. The remaining coffee farms produce less, with yields down 26 percent in a decade."
The two Giovanni images (Figs. 4, 5) show a comparison of average annual surface skin temperatures in Costa Rica from the Modern Era Retrospective-analysis for Research and Applications (MERRA) data set. The two images are for 1980 and 2010, at the beginning and end of the MERRA data set, respectively. 2010 was a very warm year, essentially tied with 2005 for the warmest year recorded in the instrumental data set dating back to about 1880. By plotting temperatures at these two ends of the data set, with 1980 considerably cooler than 2010 (similar to the time-series trend for Colombia shown in Figure 3), the differences in regional climate conditions can be clearly seen, highlighting the reported trends. The temperature range is approximately 20-29 °C (68-84 °F). [Remember that these are temperatures averaged over the entire year; winter temperatures could be somewhat cooler and summer temperatures somewhat warmer than the temperature limits used for the Giovanni plots.]
Figure 4. MERRA average surface skin temperature over Costa Rica for the year 1980.
Figure 5: MERRA average surface skin temperature over Costa Rica for the year 2010.
Giovanni home page: http://giovanni.gsfc.nasa.gov