Research Summary
Is Robusta Really the Future of Coffee? New Data Says: Not So Fast.
Climate change is reshaping the future of coffee—and fast. Those of us in the industry are already living this reality. Rising temperatures, shifting rainfall, and extreme weather are cutting into yields, especially for Arabica, the more delicate of the two major commercial species.
That’s why many companies have put their bets on Robusta (Coffea canephora). With its reputation for resilience—particularly heat tolerance—it’s often painted as the logical alternative to Arabica. But emerging research suggests we need to take a closer, more critical look before we call Robusta coffee’s climate-proof savior.
What the Numbers Say
A comprehensive longitudinal study published by Jath et al. (2020) tracked Robusta yields across 798 farms in Vietnam and Indonesia between 2008 and 2017. These two countries account for 55% of global Robusta production, making the findings especially relevant.
Until recently, much of the literature leaned on generalizations: Robusta grows well in 22°C–30°C, and it’s tough enough to weather future heat. But Jath’s team found that earlier claims often used vegetative vigor as a proxy for productivity—ignoring actual cherry yield.
Their findings challenge the conventional wisdom.
Key Takeaways
Optimal growing season temperatures: Around 20.5°C average.
Yield begins to drop: Once mean minimum temperatures exceed 16.2°C.
Yield drops over 25%: When average temperatures rise above 23.8°C.
Yield drops over 50%: When they rise above 25.1°C.
| Criteria | Min Temp (°C) | Max Temp (°C) | Results | Yield Loss |
|---|---|---|---|---|
| Optimal | ≤ 16.2 | ≤ 24.1 | Ideal | 0–5% |
| Suboptimal | 16.2–18.6 | 24.1–26.5 | Moderate stress | 5–25% |
| Poor | 18.6–20.7 | 26.5–29.5 | High stress | 25–50% |
| Very Poor | > 20.7 | > 29.5 | Critical stress | 50%+ |
During the flowering stage, the sweet spot was 21.7–23.4°C, with losses increasing sharply outside that range.
The conclusion? Robusta isn’t as heat-tolerant in terms of yield as many believed. Yes, it survives hotter climates. But if we’re talking about maintaining productivity and farmer income, “surviving” isn’t enough.
Implications for the Industry
This changes the conversation. Robusta’s resilience is more limited than previously assumed. And if global temperatures continue to rise, even Robusta-producing regions will face significant losses unless we adapt.
Jath et al. note the importance of genetic diversity within Robusta. Different genotypes may react differently to heat, opening the door for selective breeding or genetic research focused on yield stability in rising temperatures.
They also found that for every 1°C increase above a 16.2°C minimum, Robusta yields can drop 350 to 460 kg per hectare.
Where Do We Go From Here?
At Karmic Circle Coffee Trading, we got into this business with eyes wide open. We knew coffee’s future depended on adapting—not just sticking with what’s worked so far.
This research underlines the importance of continuing to invest in:
Genetic trials for heat resilience
Region-specific growing strategies
New processing and farming methods
Because Robusta might be part of the solution—but not the whole answer.
References
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