EcoMyths: Why your coffee may go extinct

April 1, 2013

Kate Sackman

Sacré bleu! Scientists at Kew Gardens, London recently predicted that before the century's end, global warming could force into extinction the plant source of most of the world’s coffee. Two main coffee species create the coffees that most people drink: Arabica (Coffea arabica) and Robusta (Coffea robusta). Arabica is most widely enjoyed: about 70% of all coffee varieties consumed globally derive from the Arabica bean. So when we heard that the Arabica plant could go extinct where it grows wild, in the Ethiopian rainforests, we had to know more. We asked two scientists why wild Arabica, as opposed to cultivated Arabica grown on plantations, is so critical to the coffee industry.

Not one to take such threats to my morning coffee routine lightly, for our regular EcoMyths segment, I invited Nicole Cavender, PhD, vice president of Science and Conservation at the Morton Arboretum and Abigail Derby Lewis, PhD, conservation ecologist at the Field Museum of Natural History, to talk with Jerome and me about the future of the wild Arabica coffee plant. This also gave us the opportunity to ask our experts about biodiversity, what that high falutin’ word means, and why it matters.

Cavender, a PhD in horticulture and crop science, says that Arabica coffee grown in the wild is important because of its genetic diversity. By contrast, farm-grown Arabica is genetically fairly uniform and therefore more vulnerable to the impact of diseases, pests, and climate change. Because wild Arabica has a more diverse gene pool, it provides a fallback in case the cultivated versions of Arabica die off or are threatened.

“Biodiversity” describes the many different genetic variations of a single species of plant or animal, as with wild Arabica. The word biodiversity can also describe a variety of different species within a defined ecosystem, such as the number of plant varieties in a prairie. The more plants in a prairie, the more biodiverse it is; this makes the prairie more resilient to drought and other stresses and thus more likely to remain healthy in the long-run.

Derby Lewis, who for the Field Museum, studies the impact of climate change on biodiversity, has worked in some of the most biodiverse and threatened areas of the world. In Chicago, she leads the Climate Change Task Force for Chicago Wilderness. She was instrumental in developing the Chicago Community Climate Action Toolkit. Derby Lewis wishes biodiversity were a more commonly used term in the U.S. More people would understand the importance both of preserving habitat and the genetic bank. She encourages individuals to help preserve biodiversity in their own backyards and neighborhood parks by planting a wide variety of flower, bush, and tree species. Ideally, Derby Lewis recommends we use native plants - meaning species that have naturally grown in this region - for hundreds of years or more. Because of their naturally deep roots, native plants require less energy, pull more carbon out of the air, and store more water underground.

Cavender points out that in northern Illinois, native ash trees are an example of what could happen to the Arabica coffee plant as the climate continues to change. The emerald ash borer has attacked our Ash trees since 2002. The pest seems thrive due to global warming.  As the climate changes, precipitation levels change and invasive species now threaten plants even in their native habitats. Protecting and maintaining a biodiverse population of plant species in its native habitat, such as the Arabica coffee plant, is one of the many ways we can improve species sustainability well into the future.

Cavender left us with this bit of wisdom: “Every time you take a sip of coffee, think about the importance of biodiversity”. Well said.