Robusta is on the rise. What once used to account for 30% of global coffee production has recently jumped all the way up 43%. The primary factor for this shift? Climate change. Robusta is generally believed to be more resilient to a warming planet, which is true; robusta can handle higher temperatures than Arabica. But that’s not the whole story, with one of the preeminent coffee researchers grabbing headlines by calling robusta’s climate resilience “an internet myth.”
It sounds very hot take-y, and admittedly I was fully ready to dismiss it as bluster, or even write a fiery op-ed against whichever snooty coffee bro said it. Except that the person in question is none other than Dr. Aaron Davis of London’s Royal Botanic Gardens, Kew.
Dr. Davis is most known in coffee circles for his work discovering (or rediscovering) coffee species outside of the typical Arabica/robusta paradigm that may offer a viable alternative in the face of a changing production climate. His previous research includes discoveries Stenophylia, Excelsa, six native species in Madagascar, and Libex, a Liberica and Excelsa hybrid.
For his latest paper, recently published in the journal Sustainable Development, Dr. Davis along with Akshay Dashrath and Justin Moat examined the current scientific evidence available regarding robusta and climate resilience. Looking at over 50 previously published scientific studies on the topic, the team took a more granular approach to the question.
Heat tolerance, they find, is only part of the equation, and reliance upon it as the metric is what leads to the misleading claim about robusta’s climate resilience. The other main factor is water needs. And while Arabica and robusta production have similar annual water needs, in practice the two species vary greatly.
For their research, Dr. Davis and team examined information on native populations of robusta and Arabica from various producing regions in Africa, Asia, and South America. Per the paper, “naturally occurring Arabica receives most of its rainfall during 8–9 months of the year, with low rainfall (i.e., a distinct dry period) for 3–4 months of the year… Indigenous robusta receives the bulk of its yearly rainfall for 9–10 months in each year, usually with a shorter, less severe, 2–3-month drier period.”
In short, robusta isn’t necessarily equipped to handle longer periods of dry weather. So in practice, farmed robusta, which has the same water needs as wild robusta, requires assistance, ie additional irrigation, fertilizers, etc. Thus, robusta as a climate-friendly alternative falters due to its need for additional water, often in areas where water availability is already limited. Fertilizers meanwhile, particularly the synthetic type that are more cost-effective, “is a large contributor to greenhouse gas emissions” for global agriculture.
Viewed wholistically, when looking for an alternative coffee species in the face of climate change, robusta, it turns out, may actually contribute more to those factors than alleviate them. So the “internet myth” about robusta may be more than just a snappy headline.
“I found it troubling that people weren’t interpreting the science correctly and that they were advocating robusta as the savior of the coffee sector under climate change,” Dr. Davis tells Reuters. “Robusta is more heat-tolerant than arabica, but it’s drought-intolerant.”
Zac Cadwalader is the managing editor at Sprudge Media Network and a staff writer based in Dallas. Read more Zac Cadwalader on Sprudge.
