Climate Change & The Coffee Industry

In February 2013, a Guatemalan smallholder named Mauricio Mendez watched coffee leaf rust destroy a harvest his family had protected for decades. "I never thought this would happen to me," he told Guatemala's Prensa Libre (McCook). His farm had survived the first major rust outbreak in the 1980s without serious damage. This time, the fungus reached altitudes where it had never been a threat. A neighboring farmer, Bartolo Chavajay, couldn't contain his tears. The rust had destroyed his entire harvest, his only source of income.

Rising temperatures are shrinking the altitude band where arabica grows, and the farms behind your favorite coffees are already adapting to survive. The science behind this shift is specific and measurable. So are the responses from producers in Honduras, Nicaragua, and Costa Rica who've spent the last decade rebuilding around it.

How does climate change affect where coffee can grow?

Arabica coffee, which accounts for roughly 70% of global production and includes nearly all specialty-grade coffee, grows in a narrow altitude band between about 2,000 and 6,000 feet (Jaffee). That's a tight window. It depends on temperatures staying within roughly 15°C to 28°C year-round (McCook). When the climate warms, that viable band shifts uphill. And there's only so much hill.

Stuart McCook, a historian of coffee agriculture, describes this dynamic using a three-belt model. Picture a tropical mountainside divided into altitude zones. In the highest, coolest belt, diseases like coffee leaf rust exist but don't cause serious damage. Farmers don't need special measures. In the lowest, warmest belt, the fungus thrives so aggressively that production becomes unprofitable. Most of the world's coffee grows in the middle belt, where coexistence with disease is possible but requires constant effort (McCook).

Climate change is compressing those belts. Warming temperatures push disease-favorable conditions uphill into zones that were historically safe. The boundaries "ebb and flow according to changing economic and ecological conditions," McCook writes, and coexistence with the rust "is always provisional." A 2020 analysis of climate projections estimates that half the land currently used for coffee farming will be unproductive by 2050 (Gokavi and Mote).

What is coffee leaf rust, and why is it spreading?

Coffee leaf rust is a fungal disease that spreads through airborne spores, attacks leaves from the bottom up, and can destroy an entire crop in a single season. The spores germinate optimally between 21°C and 25°C (McCook). Heavier rainfall splashes them further and accelerates spread. As the fungus kills leaves, photosynthesis drops, the plant starves, and yields collapse. Fewer leaves this year means fewer branches producing fruit next year, so a single bad season compounds into multiple years of loss.

Starting in 2007, a wave of severe outbreaks swept through Colombia, then across the Andes, Central America, and the Caribbean. McCook calls it "the Big Rust." Between 2007 and 2011, Colombia's production fell by a third. By 2012 and 2013, the epidemic had reached peak intensity across an arc from Peru to Mexico. El Salvador's production fell 57%, Mexico's 46%, Peru's 39%. Across Central America as a whole, the decline was 16% (McCook).

The trigger was climate change. Warming minimum temperatures and irregular rainfall shortened the rust's latency period, the time between infection and visible symptoms. That let the fungus reproduce faster and hit harder at higher altitudes where it hadn't previously caused significant damage (McCook). Several Central American countries declared states of emergency (Hoffmann). Honduras was among the hardest hit, with the government issuing an international emergency appeal describing the outbreak as a "plague" devastating the country's primary export crop ("CWS Emergency Appeal").

What other threats do coffee farms face from a changing climate?

Rising temperatures and shifting rainfall create favorable conditions for pests that were previously manageable. The coffee borer beetle, the most damaging insect pest in coffee production, spends its entire life cycle inside the coffee fruit. That makes pesticides almost useless against it. Warmer temperatures speed up its reproduction cycle, and a 2018 study of Mesoamerican coffee farms found it struggles to thrive in shaded environments (Groenen).

Root-knot nematodes present a different kind of problem. They attack the root system, and wet soils create ideal conditions for their population to explode. The chemical treatments that control them can be toxic to the coffee plant itself. There are irrigation and land-use adjustments that help, but they're expensive and depend on predictable conditions that are becoming less common.

Then there's rainfall. Coffee bloom is triggered by a prolonged period of rainfall (Hoffmann). When that pattern becomes erratic, bloom timing shifts. In regions where wet and dry seasons blur, it's common to see multiple flowerings on a single tree (Hoffmann). That complicates harvest logistics, increases labor costs, and creates inconsistent quality across a single farm's output.

What happens when coffee farming becomes unprofitable?

When coffee can't cover its costs, farmers abandon their land, and the environmental systems those farms supported collapse with them. The Wall Street Journal reported that the collapse of world coffee prices affected an estimated 125 million people worldwide (qtd. in Jaffee). In Central America alone, 200,000 permanent and 400,000 temporary coffee workers lost their jobs. Nicaragua was the worst hit: 122,000 workers were fired. Regional famine followed in the northern Matagalpa region. Fourteen unemployed coffee pickers starved to death during August 2002 alone (Jaffee).

The revenue split tells the structural story. By 2001, the global coffee market had grown to nearly $80 billion in annual sales. Producer countries earned less than $6 billion. Their share had dropped from 33% in 1989 to under 8% in just over a decade (Jaffee).

When farming stops paying, farmers convert their land. More than 20,000 hectares of shade-coffee agroforestry were abandoned or converted in El Salvador and Honduras combined (Jaffee). That loss reaches beyond coffee. Shade-coffee farms are ecosystems. They fix carbon, produce oxygen, stabilize soil, and host diverse plant and animal species. When they're cleared for cattle grazing or other crops, all of those functions disappear. "The coffee production crisis in Central America is taking a toll on environmental equilibrium," as journalist Jose Eduardo Mora reported, with increased soil erosion and lost carbon sequestration across abandoned plantations (Jaffee).

This creates a feedback loop. Climate change damages coffee economics. Damaged economics push farmers to clear forest and shade systems. Clearing those systems reduces carbon capture and accelerates warming. The cycle compounds itself.

How are producers adapting at the farm level?

Farmers are responding with specific strategies: varietal diversification, shade management, processing innovation, and biodiversity conservation. The solutions are real. They're also expensive and require the kind of financial stability that most smallholders don't have.

After the rust crisis devastated Honduras, many producers shifted to rust-resistant varieties like Lempira, Parainema, Icatu, and IHCAFE 90 while maintaining quality through careful cultivation and processing. In Marcala, Central America's first coffee Denomination of Origin (established 2005, covering 19 municipalities across the Montecillos range), the COMSA cooperative supports over 1,200 producer-members in these transitions. Their La Fortaleza demonstration farm teaches organic and agroecological practices to farmers across the region.

At Finca San Isidro in Honduras, fourth-generation farmer Katia Duke grows coffee under Inga trees (a nitrogen-fixing species) and hardwood forest canopy at 1,300 meters. Her property hosts over 180 orchid species and provides habitat for hummingbirds and butterflies. Duke started her own operation in 2012, the same year the rust crisis hit Honduras hardest. The crisis became her turning point toward specialty production and ecological farming. She chose Catuai deliberately for her elevation range, knowing the variety is extremely susceptible to leaf rust but produces exceptional cup quality when managed with shade and organic inputs. That tradeoff, vulnerability balanced by ecological infrastructure, is what climate adaptation looks like in practice.

Costa Rica's Aquiares Estate is working on what climate-adapted coffee looks like a generation from now. Their 25-variety test garden, developed with CIRAD and CATIE research institutes over a decade-long collaboration, evaluates cultivars bred specifically for climate resilience. One result is the Centroamericano H1 hybrid, an F1 cross between Sarchimor T-5296 and Rume Sudan (an Ethiopian landrace) that yields 22-47% more than conventional varieties while maintaining disease resistance and high cup quality. The farm captures 3,790 tons of CO₂ annually and emits only 1,042, making it carbon negative. Eighty percent of their 924 hectares grow under shade from 40+ tree species, with 200 hectares of protected rainforest serving as a wildlife corridor connecting two national parks. Loom sources from Aquiares through Ally Coffee.

Shade management runs through both approaches. Coffee growing wild in forests provided the original clue: the density and diversity of surrounding vegetation matters. Shade trees offset rising temperatures, create habitat for birds and insects that prey on coffee pests, and slow cherry maturation in ways that produce more complex flavors in the cup. Duke's Finca San Isidro and Aquiares both demonstrate that ecological farming and specialty quality reinforce each other.

Plant spacing also matters. Greater distance between coffee plants makes it harder for fungal spores to transfer plant to plant and reduces host density for pests. Combined with crop rotation and interplanting with fruit, vegetable, and grain crops, these methods diversify the biology in the field and allow soil to regenerate between growing seasons while providing alternative income streams.

What does this mean for your cup of coffee?

The coffees you enjoy depend on specific climate conditions at specific altitudes, and the cost of protecting those conditions flows through the entire supply chain. Arabica grown between 1,200 and 1,800 meters in a region like Marcala, Honduras, sits in that middle altitude belt. The flavors you associate with specialty coffee, the brightness, the complexity, the clean finish, come from slow cherry maturation at altitude. As that band compresses, the geography of quality coffee compresses with it.

Adaptation costs real money. Rust-resistant seedlings, shade tree planting, processing infrastructure, organic certification, water recycling systems. These are survival investments for farms operating on thin margins. And they only happen when farmers have enough financial room to plan beyond the next harvest.

That room comes from the price paid for green coffee at every stage of the chain. Buyers and exporters who pay prices reflecting the true cost of climate-adapted production give farmers the freedom to make long-term decisions. Roasters who choose those importers extend the chain further. And when you choose a roaster that sources with these relationships in mind, you're funding the specific infrastructure that keeps these coffees viable.

The price of a bag of coffee already reflects dozens of decisions made at the farm level. When those decisions include shade canopy management, varietal diversification, water conservation, and soil restoration, the coffee is better and the farm has a future.

Works Cited

"CWS Emergency Appeal: Coffee Rust Plague (Honduras)." ReliefWeb, 6 Nov. 2013, https://reliefweb.int/report/honduras/cws-emergency-appeal-coffee-rust-plague-honduras.

Gokavi, Nagaraj, and Kishor Mote. "Impact of Climate Change on Coffee Production: An Overview." 2020.

Groenen, D. "The Effects of Climate Change on the Pests and Diseases of Coffee Crops in Mesoamerica." Journal of Climatology & Weather Forecasting, vol. 6, no. 3, 2018. doi.org/10.4172/2332-2594.1000239.

Hoffmann, James. The World Atlas of Coffee. 2nd ed., Bloomsbury, 2018.

Jaffee, Daniel. Brewing Justice: Fair Trade Coffee, Sustainability, and Survival. University of California Press, 2007.

McCook, Stuart. Coffee Is Not Forever: A Global History of the Coffee Leaf Rust. Ohio University Press, 2019.