Arabica growing regions are shrinking: Scientific evidence from climate change

For many years, climate change was considered a distant and difficult-to-quantify risk for Arabica coffee. However, scientific studies over the past decade have gradually transformed that risk into concrete and comparable figures. When climate models, crop growth simulations, and synthesis analyses are considered together, a relatively consistent picture emerges: the area of land suitable for Arabica is shrinking, and this trend is structural rather than temporary.

Shrinking ecological space under the impacts of temperature and rainfall

Numerous climate simulation studies and land suitability assessments indicate that rising global average temperatures, combined with increasingly irregular rainfall patterns, are significantly reducing the ecological space suitable for Arabica. In global projection models, traditional Arabica-producing regions, particularly lowland areas and tropical zones are identified as those experiencing the earliest and most severe impacts.

One notable feature of these findings is not only a reduction in total area, but a change in the spatial configuration of suitable zones.

Rather than disappearing uniformly, Arabica-growing areas tend to shift toward higher elevations with cooler temperatures, or become increasingly constrained and fragmented as optimal climatic conditions are no longer maintained (according to the study by Ovalle-Rivera et al., 2015). Under many warming climate scenarios, a substantial proportion of areas currently cultivating Arabica are projected to lose sufficient suitability, even if farming practices are improved.

From area to yield: cascading effects of climate stress

The contraction of ecological space is not merely a geographical issue; it also leads to direct consequences for plant growth and productivity. A study published in 2025 by Peruta et al., using continent-scale simulations of coffee plant growth, shows that Arabica faces a risk of yield decline across most major producing regions.

According to the simulation results, Arabica yields could decrease by 23 – 35% in Latin America and 16 – 21% in Africa, primarily due to the combined effects of rising temperatures and prolonged drought. These conditions shorten fruit development cycles, limit biomass accumulation, and weaken the plant’s physiological resilience. More importantly, the study indicates that climate stress affects not only output but also threatens bean quality, by altering the balance of sugars, acids, and aromatic compounds.

This demonstrates that climate change does not operate along a single pathway, but rather creates a chain of cascading effects from ecological conditions to yields and ultimately to the sensory value of Arabica.

Consensus from global synthesis studies

Findings from individual studies are reinforced by systematic reviews that synthesize data across regions and methodologies. These reviews indicate that by around 2050, land suitable for coffee cultivation will decline in many parts of the world, with Arabica being the most affected species (according to Bilen et al., 2022).

The core reason lies in the fact that Arabica has narrower climatic requirements than other coffee species. While some species can maintain growth across wider ranges of temperature and rainfall, Arabica quickly enters a stress state when conditions exceed optimal thresholds. This convergence across synthesis studies suggests that the decline of Arabica-growing regions does not depend on a single model or scenario, but is a recurring outcome across multiple scientific approaches.

Low genetic diversity as a factor amplifying climate impacts

A key factor making Arabica particularly vulnerable to climate change is its limited genetic base. Data from World Coffee Research (WCR) indicate that most commercial Arabica varieties today originate from a very narrow gene pool, shaped by successive stages of selection and global dissemination throughout history.

This lack of diversity reduces Arabica’s ability to adapt to new environmental conditions, from higher temperatures to complex climate-induced stressors. As ecological space contracts, the absence of suitable genetic variants further increases the risk of widespread decline, rather than impacts remaining confined to specific regions.

Across climate models, growth simulations, synthesis studies, and genetic data, scientific evidence converges on a single conclusion: the decline of Arabica-growing regions is an inevitable outcome of climate change combined with the species’ inherent biological limitations. This is not simply a story of losing farmland, but a fundamental shift in the conditions under which Arabica can exist. Recognizing this scientific foundation is the first step toward understanding why the coffee industry is being forced to seek new pathways of adaptation beyond traditional Arabica.

If climate change is shrinking Arabica’s “living space”, limited genetic resources are what make the species difficult to adapt as that space changes. As temperatures rise, rainfall becomes increasingly erratic, and diseases spread more widely, the long-standing genetic constraints of Arabica are becoming more visible, emerging as a structural bottleneck for the future of the species.

Arabica’s narrow genetic legacy

From an evolutionary perspective, Coffea arabica is a unique species. It is predominantly self-pollinating and originated from a rare natural hybridization event between Coffea canephora and Coffea eugenioides, followed by expansion from a very small initial population. This evolutionary history established a low level of genetic diversity from the outset.

Modern genetic analyses show that most commercial Arabica varieties today from Typica and Bourbon to many later improved cultivars trace back to a limited number of ancestral lines, having passed through multiple genetic bottlenecks during dissemination and breeding. According to synthesis reports by WCR, Arabica’s genetic diversity is significantly lower than that of many other perennial crops, and even lower than that of Robusta.

Under stable environmental conditions, this uniformity once supported consistent quality and uniform production. Under rapidly changing conditions, however, it has become a fundamental vulnerability.

Disease pressure as an amplified consequence of climate change

Environmental stress affects coffee plants directly, and indirectly through diseases and pests. A prominent example is coffee leaf rust (hemileia vastatrix), which caused severe outbreaks in Central and South America during the 2010s. Numerous studies indicate that warmer and more humid conditions created favorable environments for the pathogen, while commonly grown Arabica varieties shared similar levels of disease resistance, enabling rapid and widespread transmission.

Similar patterns have been observed with other pests and diseases, as warming temperatures shorten pest life cycles and expand their geographic ranges. In this context, Arabica’s narrow genetic base not only reduces resistance but also amplifies systemic disease risks.

Limits of current Arabica breeding strategies

In response to these challenges, Arabica breeding programs have sought to develop varieties with improved tolerance to higher temperatures and disease pressure. However, many researchers note that the genetic material available for Arabica improvement is relatively limited, constraining both the speed and scope of progress relative to the pace of environmental change.

Even when tapping into wild Arabica populations in Ethiopia widely regarded as the species’ center of genetic diversity, the process of transferring these traits into commercial varieties remains time-consuming and involves trade-offs in yield, quality, or local adaptability.

This raises a fundamental question: Is improvement within Arabica alone sufficient to cope with increasingly complex environmental pressures?.

As the ecological and genetic limits of Arabica become increasingly evident, the coffee sector stands at a critical crossroads. One path is to continue attempting to “hold on” to Arabica through increasingly costly and risky technical interventions. The other path now supported by a growing body of scientific research and industry organizations is species diversification, aimed at expanding the adaptive capacity of coffee production systems under a changing climate.

From optimizing a single species to strengthening system resilience

For decades, global coffee development strategies have largely focused on optimizing Arabica: improving yields, enhancing quality, and expanding growing areas. However, research on climate-adaptive agriculture increasingly emphasizes that biodiversity is the foundation of resilience.

Under this approach, the goal is no longer to maintain a single species across all conditions, but to build a diversified species system in which each species or variety plays a role suited to specific ecological niches and climate scenarios. FAO and many international agricultural research organizations regard this as a core principle of sustainable agriculture in the 21st century.

Robusta and hybrids: expanding the ecological range

Among commercial coffee species, Coffea canephora (Robusta) is often the first mentioned when discussing adaptability. Compared with Arabica, Robusta has a broader temperature tolerance, greater relative drought resilience, and better resistance to several major diseases.

Breeding programs led by World Coffee Research (WCR) show that Robusta and Arabica – Robusta hybrids (such as F1 hybrid lines) can play an important role in stabilizing production in regions where Arabica is gradually losing suitability. Notably, F1 hybrids are developed not only to improve yields, but also to combine Arabica’s sensory quality with Robusta’s biological resilience.

Liberica and “marginal” coffee species returning to the center

Beyond Robusta, a growing research direction involves re-examining coffee species that were once considered secondary, most notably Coffea liberica. Liberica can grow under higher temperatures, greater humidity, and poorer soils than Arabica, while also showing relatively strong resistance to certain major diseases.

Recent studies on species diversity within the Coffea genus suggest that Liberica and other wild coffee species could serve as strategic genetic resources not only for direct cultivation, but also for breeding and improving the adaptive capacity of future commercial varieties. As Arabica is constrained by a narrow “climate window”, these species offer new ecological space that the coffee sector has historically underutilized.

The role of research and policy in the transition process

Species diversification cannot occur spontaneously. Reports from WCR and numerous research institutes emphasize the central role of breeding research, genetic resource conservation, and supportive policies. The utilization of wild genetic resources, the development of new varieties, and their introduction into production all require time, investment, and coordination among scientists, farmers, and businesses.

In many cases, the challenge lies not in whether new varieties exist, but in market acceptance and value chain adaptation. This calls for a long-term communication and education process, in which quality is understood more broadly not merely as the reproduction of familiar flavor profiles, but as adaptation to a new global reality.

In conclusion,

Under the increasingly visible impacts of climate change, the contraction of Arabica-growing regions is no longer a hypothesis but a scientifically documented trend. Ecological and genetic constraints are placing Arabica under structural risks, forcing the coffee sector to reconsider a development strategy based on a single species. In this context, species diversification is not merely an adaptation measure, but a foundation for building a more resilient and flexible future for the coffee industry.

Images collected from Chepsangor Hills, Ninety Plus Coffee Estates, My Liberica, and other sources.

1. Why are Arabica growing regions shrinking globally?

Rising average temperatures and increasingly unstable rainfall patterns mean that many regions no longer meet Arabica’s optimal ecological requirements. Climate models show that suitable growing areas are shrinking, especially in lowland and tropical regions, while upward shifts to higher elevations are limited.

2. In what ways is Arabica more sensitive to climate change than other coffee species?

Arabica has a narrow “climate window”, particularly with respect to temperature and seasonal stability, making it more prone to stress when environmental conditions change. Compared with Robusta, Arabica is less flexible in adapting to higher temperatures and drought.

3. Why is Arabica’s genetic base considered a risk factor?

Most commercial Arabica today is based on a very narrow genetic foundation derived from a small number of ancestral lines. This lack of diversity reduces adaptability to new climatic conditions and increases vulnerability to widespread disease outbreaks.

4. Which diseases are exerting the greatest pressure on Arabica under warming climates?

Coffee leaf rust (hemileia vastatrix) is the most significant threat, especially as higher temperatures and humidity create favorable conditions for fungal development. In addition, the coffee berry borer is expanding its range into higher elevations.

5. Is species diversification a short-term trend?

No. It is a long-term strategy grounded in scientific evidence on climate change, biological risk, and agricultural system resilience. Diversification helps reduce dependence on a single species and enhances the coffee sector’s adaptive capacity for the future.