Coffee in a Changing Climate

Climate change and coffee: assessing vulnerability by modeling future climate suitability in the Caribbean island of Puerto Rico

Stephen J. Fain, Maya  Quiñones, Nora L. Álvarez-Berríos, Isabel K. Parés-Ramos, William A. Gould

What data were used?

This study investigated the effects of climate change on coffee production in Puerto Rico. Although coffee is grown in several countries around the world, by 1899 the country was the sixth largest producer of coffee, with over 40% of its cultivated area dedicated to coffee production. Coffee was grown in great numbers into the 1990’s, when harvests were more than 12 million kilograms per year. Coffee plants are mostly grown in mountainous regions on land that is owned by independent farmers. Two species of coffee, Coffea arabica and Coffea canephora, are plants that are shade-loving and thrive within a narrow range of climatic conditions. In other words, the plants cannot tolerate huge changes in temperature, moisture, and precipitation. Increased temperature has caused the plants to decrease quality, have stunted growth, and exhibit growth abnormalities. With reduced crops and quality, Puerto Rican farmers will have reduced yields, reduced income, and thus will not be able to hold as many employees to care for the plants and pick the coffee beans.

The authors of this study wanted to investigate how these two species of coffee plants will fair under climate change scenarios projected for the future. The scientists first gathered data about what temperature, moisture content, and precipitation amounts were favorable for the coffee plants. Then, the authors used a climate model with three different emissions scenarios (amount of CO2 that is projected to be released into the atmosphere in the future): A2 Scenario, which is the highest emissions scenario; A1B Scenario, which is the mid to low emissions model; and the B1 Scenario, which is the lowest CO2 emissions scenario. They modeled how climatic variables  (such as temperature and precipitation) will change over time under these three emissions scenarios for five time periods: 1960-1990; 2011-2040; 2041-2070; and 2071-2099.

The authors came up with an index to for each time period to assess how well coffee will fare under climate change. The index ranged from 0 to 5, with 0 being unfavorable conditions, and 5 indicating favorable coffee growth conditions.

Results

The model for 1991-2010 was used as a baseline for which to compare the other four models to. In this model, the amount of land that is most suitable for coffee growth (suitability index of 5) is confined to the mountainous regions of Puerto Rico.

The 1991-2019 coffee sustainability model, with the lightest areas least suitable for coffee growth, and the darkest areas most suitable for plant growth.

Other models for future years under the high, mid-low, and low CO2 emissions scenarios all indicate that as climate change induces increased warming over Puerto Rico, less and less land will be suitable for coffee growth.

Under the high emissions scenario (A2), the top ten coffee-producing areas in Puerto Rico are expected to lose 47% of their high-quality coffee producing range by 2040! Under the low emissions scenario (B1), this loss is reduced to 21% by 2040. After the year 2040 in both scenarios, the amount of land that will be lost for coffee production greatly increases. Under the low emissions scenario (B1), the island’s top ten producing municipalities may face a 60% decline in prime coffee-growing habitat. Under the high-emissions scenario, this number increases to 84%.

The models for high CO2 emissions scenario (A2), mid-low CO2 emissions scenario (A1B), and low CO2 emissions scenario (B1) for the five time slices studied. Notice that in all models, the amount of suitable land for coffee growth decreases dramatically (less and less dark brown area) through time.

In the A2 (high emissions) scenario, the island only retains 289 km2 of highly suitable growth space (index of 5 in figures) from 2041-2070, which declines to only 24 km2 by 2071-2099! For comparison, under the low emissions (B1) scenario, Puerto Rico retains 680 km2 of highly sustainable coffee growth space by 2041, which is reduced to an area of 329 km2 by 2071-2099.

Why is this study important?

As less land is available to grow high-quality coffee, the island of Puerto Rico will lose money from reduced exports. In effect, the people of the island who rely on the coffee industry will suffer financially, as the growth of the plants provides thousands of residents with income and financial stability. This study highlights just one way in which climate change will negatively affect a country’s economy and people.

The big picture

Climate change will lead to increased warming in tropical and sub-tropical areas, such as Puerto Rico. With increased warming comes a change in climate and weather regimes, most of which will have a negative impact on the region and the people who live there.

Citation

Fain, S. J., Quiñones, M., Álvarez-Berríos, N. L., Parés-Ramos, I. K., and Gould, W. A., 2018. Climate change and coffee: Assessing vulnerability by modeling future climate suitability in the Caribbean island of Puerto Rico. Climatic Change 146, 175-186.

 

 

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