Although petroleum is easily Colombia's biggest export, the one more associated with Colombia is coffee. Coffee is both a point of pride and a significant economic driver for Colombia. Coffee cultivation employs approximately 570,000 families, providing 800,000 direct jobs and another 1.6 million indirect jobs, accounting for the employment of roughly 25% of Colombia's rural population .

Colombia's environment makes it an ideal place for the cultivation of Arabica, its primary coffee varietal. Arabica accounts for 70% of all coffee sold worldwide and grows best in areas with a steady, year-round rainfall of between 1.0 to 1.5 meters? and at altitudes between 1,300 and 1,500 meters. It is no wonder, then, that Colombia's southwestern mountain region is also its prime growing area. This region has year-round precipitation ranging between 0.5 and 3 meters (1-1.5m on average); temperatures between 8°C and 24°C and an exceptionally rich soil due largely to Colombia's remarkable biodiversity.

A Changing Climate Threatens Harvests

Steadily, however, these natural advantages are being eroded as a changing climate alters Colombia's coffee growing terrain. Daily high temperatures in the mountains have been increasing by an average of 0.1°C per year, while daily lows decreased by an average of 0.5°C per year between 2008 and 2011. At the same time, precipitation patterns have changed drastically. The onset of the rainy season has shifted forward and rainfall patterns have changed from steady precipitation to marked swings between dry sun and heavy downpours.

These changes have placed enormous stress on coffee plants, resulting in crop yields of both diminished size and quality for many coffee growers. The higher high temperatures have also encouraged the population growth and uphill spread of coffee pests such as the "coffee rust" fungus and the coffee borer beetle, which can wreck havoc on a plantation. Coffee pests aren't the only creatures that have moved higher with the changing weather, however. Other plants and animals have also been moving slowly uphill, where they act as invasive species competing for the same nutrients as the coffee plants. This makes life harder for coffee growers, who must exert extra effort to ward off both the newcomer species and the traditional coffee pests.

How Coffee Farmers Adapt to a Changing Climate

The International Coffee Organization (ICO) - the largest international lobby for the coffee industry - lists climate change as one of the most important factors adversely affecting small coffee farmers. The ICO goes on to point out that "Smallholders produce the bulk of the world's coffee and the industry cannot afford a steeply falling output in this sector". Coffee growers in Colombia are already keenly aware of this and have been working hard to adapt to their new reality through a combination of varied farming practices and heightened pest control.

To guard against the economic catastrophe of a failed coffee crop, many growers now mix in other cash crops such as yucca and tomatoes, alongside their coffee plants or experiment with growing hybrid coffee plants that are better adapted to climate extremes or are better able to resist pests. Some growers have explored alternate business practices that allow them to diversify their income, rather than relying solely on coffee production. But even in these cases, however, coffee remains vital to the survival of the plantation.

The greatest tools that farmers have to fight the pests are array of chemical and biological pesticides and tedious manual labor. The primary biological pesticide in use is a fungus called Beauveria bassiana. B. bassiana is a predator of the coffee rust fungus and has been used extensively throughout modern coffee cultivation. It is sensitive to humidity, however, needing humid soil to grow. As many coffee growing areas now experience longer dry hours during the day, B. bassiana's effectiveness has slowly diminished.

Two coffee plantations, or Fincas, serve as examples of the challenges in adapting to climate change and a third demonstrates the difficulty of measuring climate change and coordinating comprehensive efforts to combat it.

Smallholders Struggle to Stay Afloat

Juan Gildardo Giraldo Suárez manages Finca el Llano, a family-run plantation of roughly 150,000 coffee plants in the idyllic town of Jardín: "The truth is, the climate has been a problem for us lately," he says. "In the past four or five years, it's been very difficult to plan and care for our crops because we haven't been able to predict the weather like before."

Up until four or five years ago, he explains, weather cycles had remained fairly consistent. During the dry season, the farmers knew roughly how much sun and what temperatures to expect. Likewise, the rain fell in very consistent patterns during the rainy season, to which the coffee grown in the region was well adapted. Now, however, the rain falls more erratically and in more intense downpours.

These effects translate to additional working hours without added pay for the workers of El Llano, who must tend to young, temperature-vulnerable plants and spend more time combating pests. To ensure income in the case of a bad coffee harvest, Juan Gilardo and his family mix in crops such as yucca and tomatoes. Adding to their troubles, the higher temperatures cause fewer flowers to grow, from which coffee beans develop, leading to smaller harvests.

Cenicafé, the Colombian coffee research institution, has developed a selection of hybrid varietals, bred for various traits. Some are more resistant to pests or to environmental conditions such as extended sunlight, while others are bred for more desirable flavor profiles. To this end, el Llano has increasingly cultivated a strain called Castillo el Rosario, which is a pest-resistant varietal that they hope will help restore their harvest sizes in the near future.

Pest control represents a significant drain on resources for a Finca the size of el Llano. Only 10 people work the steep mountainside plots during the harvest and the increased pest load requires many more hours spent manually inspecting and removing infected leaves and berries. Pesticide use helps to cut down on the manual labour, but cannot be relied upon extensively. The Achilles heel of chemical pesticides is that each formulation selects for the few bugs capable of resisting its effects. If you go straight to the strongest formulation and select for those that can live through the experience, you quickly have no tools left, with which to fight off the next infestation.

Juan Gildardo also uses coffee rust predator B. bassiana, but the lengthening dry daytime periods frequently render the soil too dry for it to grow and the heavy rains then wash it away, along with topsoil.

Larger Coffee Farms, More Diversified Business Models

Further south, the Hacienda la Venecia plantation provides a glimpse of what bigger, wealthier plantations can do to mitigate the effects of climate change. In addition to coffee cultivation, Juan Pablo Echeverría, the general manager of Hacienda la Venecia, has diversified his plantation's business profile to incorporate tourism and has invested heavily in business relations with high-end specialty roasters in addition to experimenting with hybrid Arabica coffee varietals.

Besides the roughly 1.3 million coffee plants on the plantation's grounds, there now sit several hotel buildings complete with a pool and restaurant and a secluded hostel for travellers on a lower budget. Tours of the plantation are offered daily, complete with working examples of the entire coffee making process. La Venecia focuses on high bean quality (rather than quantity) and has forged business relationships with high-end roasters willing to pay a premium for beans and to pass that cost along to their consumers. This enables la Venecia to cover the cost of low-quality beans in their harvest that they would otherwise struggle to sell.

Like el Llano, la Venecia combats coffee pests with both pesticides and manual labour. In addition, La Venecia has a much larger workforce, which allows it to invest more time in manual inspection of coffee plants, thereby reducing its reliance on chemical pesticides.

Coordinating pest control practices poses another challenge. When asked if neighbouring smallholder farms benefit from la Venecia's pest control efforts, Juan Pablo replies that the reverse is closer to the truth: "The bigger problem is when neighbours don't make adequate pest control efforts," he explains. In this scenario, those neighbouring Fincas act as pest ‘reservoirs', from which successive infestations can be launched. Solving this problem requires a level of regional coordination and government support that doesn't yet exist. "I can't pay for [my neighbor's] pesticide use and remain profitable," Juan Pablo adds.

One advantage of la Venecia's business success is that the Finca has more latitude to experiment with coffee cultivars. Juan Pablo has established several experimental plots to study which hybrids work best for the company. Running these experiments presents another challenge, however. It takes a minimum of 1.5 years to acquire preliminary data from an experimental cultivar. In reality though, according to Juan Pablo, you need at least two to three years to make a fully informed decision. Given the recent unpredictability in weather patterns, he is concerned that by the time those two to three years have passed, new hybrids would need to be planted to study the impact of new climate conditions.

Six years ago, Juan Pablo says, an el Niño event caused a 30% reduction of his Finca's harvest. La Venecia has worked hard to guard against such events since then, but what would happen if several strong climate anomalies were to occur consecutively, as some climate models predict and as is happening right now in northern Peru? "A loss in production that strong two years in a row," says Juan Pablo, "we couldn't endure it."

The Uneven Distribution of Climate Change

Measuring climate change and predicting how it will affect a given region is a monumentally challenging task and one made even more complicated in mountainous regions, where the rugged topography generates many microclimates in one general area. In these regions, one valley can be dry and sunny while rain inundates the neighbouring valley.

Finca la Pradera, a plantation owned by Range Colombian Coffee, situated in Calarcá, near the city of Armenia, perfectly highlights this phenomenon. While other plantations scramble to adapt to their changing climates, la Pradera' valley has experienced almost no change in weather patterns at all. Not even the extreme effects of the 2015 la Niña event, which has wrecked havoc with Colombia's climate for the past two years, affected this small region of the state of Quindío.

Whereas fully organic farming methods are either impractical or ineffective in the face of changing weather and surging pests, the crew at la Pradera has been able to pursue a largely organic farming pipeline that allows them to sell their beans at premium prices around the globe. They must still include some measure of chemical pesticides in their mix, but they are able to rely much more on the help of B. bassiana and on painstakingly removing infected leaves and berries by hand.

Luis Eduardo García Morales, the owner of Finca la Pradera and Dr Juan Bueno, a microbiologist who works with the Finca, explain that one of the key benefits of using B. bassiana is that it evolves at roughly the same pace as its prey. That means that as it fights the coffee borer, it kills the microbes that are easiest for it to hunt first, thereby selecting for microbes that have some advantage against falling prey to B. bassiana. As food for B. bassiana becomes scarce, the bassiana microbes that have a genetic advantage enabling them to capture hardier prey become selected for. This leads to a cycle known in biology as the Red Queen Race, in which predator and prey continually adapt to each other's tactics, each keeping the other somewhat in check.

Scientists and coffee pests also engage in a Red Queen Race, but in this case, the scientists are at a clear disadvantage. While selection of pesticide-resistant pests can occur in a single growing season, it typically takes around three years for a new chemical pesticide to go through testing and come to market. During this time, the new pesticide runs the risk of becoming obsolete before even being put to use.

Many scientists are actively researching the possibilities of developing new biological pesticides, such as novel strains of B. bassiana, but development times for these strategies are even longer, more costly and face some backlash from people who are wary of lab-grown organisms.

So how long can Finca la Pradera's good climate luck hold? "That's something that worries us," admits Luis Eduardo. For the moment, there is neither any reason to expect Calarcá's microclimate to change, nor any reason to expect it to remain untouched, amounting to a disquieting uncertainty.

"We want to pursue more organic methods," Luis Eduardo says. "That's an important part of who we are." This desire runs deep. Beyond environmental concerns or desires to court the high-end organic coffee market, la Pradera's focus on traditional farming methods connects them to the traditions and practices of their ancestors who populated this region.

That said, what would they do to adapt if the climate turned against them? How would they combat a sustained increase in pests that strained their ability to conduct pest control by hand? Dr Bueno mentions the advent of CRISPR, a new genetic technology that makes changes in an organism's own genome to bring about some desired change, rather than introducing genes from other organisms, as happens with so-called GMOs. In this way, Dr Bueno explains, you could continue using organic practices with better-adapted plants and pesticidal fungi. Luis Eduardo ponders this for a moment and then exclaims "that would be awesome!" This is the sort of future that he can envision working towards.

So what does this all mean? Is the world facing an imminent coffee shortage due to a changing climate? Not necessarily, but the coffee industry and its billions of consumers are not out of the woods yet. For the time being, coffee growers are proving themselves quite adaptable to their changing climate, but the strain is showing in the upward trend of coffee prices around the globe. Studies by the ICO suggest that prices may stabilize in the future and that production in some countries, such as Ethiopia and Vietnam may increase as warming temperatures make more ground available for coffee cultivation, but much will depend on factors outside the coffee industry. Opening up more land to coffee plantation, for instance, must be balanced with competing needs for that same land and growers can expect considerable competition in this area.

There remains much that people can do to stave off a coffee-free future. Fedecafé, the Colombian coffee growers federation, already provides financial incentives to growers for planting pest and climate-resistant hybrids. Governments can invest in better weather-sensing infrastructure and communication networks between growers. Incentives can also be offered to budding scientists to conduct research in solutions to things like coffee pests. Colombia's long history of civil war has resulted in a flight of many scientists from their country. With that war now coming to an end, now is a good time to give them reasons to return.

Your coffee won't disappear tomorrow, but keep an eye on places like Colombia for what the future holds. As one of the world's three biggest coffee producers, what happens here will affect the entire coffee market.

This Author

Dr Forest Ray holds a PhD in biochemistry from Columbia University. He writes about ecological and conservation topics throughout Latin America and is a regular contributor to the Ecologist and Verge Magazine. He currently lives in Medellín, Colombia.