DAK LAK, Vietnam – For coffee lovers, the brew of the future is shaping up to be bitter and pricey, as climate change parches the world’s key growing regions.

Increasingly erratic weather is putting crops at risk globally. Hardier varieties are expected to fare better, and for coffee that means strong, earthy robusta. But in Vietnam, the top producer of these beans, alarm bells are ringing.

“We have to dig deeper to get water,” Ms Tran Thi Lien, 46, said at her 1ha farm in Dak Lak province in the country’s Central Highlands. “Some years, we don’t have enough water for irrigation. And some years, there’s too much rain.”

Tougher growing conditions have led Vietnamese farmers to question the value of coffee as a cash crop, with some pulling out their trees to plant black pepper and durian, a fruit popular across South-east Asia and with Chinese consumers. 

Reduced supply has already pushed the robusta price in 2023 to the highest level since at least 2008 – and still, rising temperatures mean future production will fall short.

Coffee is a roughly US$200 billion (S$266 billion) industry that stretches from small farms across Brazil or Indonesia to roasters and makers of end products, such as Nestle. 

Traditionally, sellers like the Starbucks chain favour the milder, more aromatic arabica variety, whereas robusta is used for instant coffee. 

But consumers are going to have to get used to a different taste. 

A 2022 study of tropical cash crops that included arabica, as well as avocado and cashew, found that the bean was most vulnerable to climate change, with regions suitable for its production shrinking globally primarily due to increased heat.

Researchers found that it would be necessary to adapt, including by replacing arabica with hardier robusta.

Nestle, the Swiss maker of Nespresso and Nescafe, is among those grappling with the change.

“Estimates show that 30 years from now, basically 50 per cent of coffee lands as we know them today will not be viable for coffee production any more (if climate change isn’t tackled),” Mr Philipp Navratil, global head of Nestle’s coffee strategic business unit, said during an interview on a tour of some of the Vietnamese farms that supply the coffee giant.

Nestle is a major consumer of robusta – around the world, consumers drink more than 6,000 cups of Nescafe every second. It spends US$700 million each year to buy around a quarter of Vietnam’s coffee production. 

In 2022, it said it would invest over one billion Swiss francs (S$1.5 billion) by 2030 to encourage growers supplying its Nescafe brand to use more sustainable farming methods as extreme weather threatens crops, and to adapt. That includes replacing existing trees with varieties that can better cope with climate change. 

But even the toughest beans will be tested as temperatures rise.

“Robusta is not a silver bullet for climate change,” said Ms Jennifer Long, chief executive officer of World Coffee Research, an organisation formed by the global coffee industry in 2012 to boost innovation.

“It’s more tolerant to heat and to some diseases and pests, but we are still learning robusta’s limits.”

In an October report, World Coffee Research said the world may face robusta shortages in 2040 of as much as 35 million bags when taking into account rising consumption trends and the impact of climate change on production. (The world currently produces close to 80 million bags of robusta a year.) 

Ms Long said changing weather patterns could lead to dramatically lower yields, which in turn would leave millions of smallholder farmers – who produce 60 per cent of the world’s coffee – vulnerable to economic and food insecurity. Vietnam’s industry is made up of a patchwork of growers who tend plots around 1ha to 2ha in size.

Prolonged dry periods in Vietnam and lack of irrigation water in recent years have already severely affected the productivity of robusta coffee farms in the Central Highlands, according to a study published in 2021 by authors from organisations including Vietnam National University.

The nation is also bracing itself for the impact of El Nino over the coming months.

Under pressure from heat and water shortages, Ms Lien is seeing the benefit of more sustainable farming practices, including those supported by Nestle. 

She and her neighbours have cut back on chemical fertilisers and provided shade for coffee shrubs, so they are less exposed to the scorching sun. She has also planted black pepper and betel nut to diversify.

“When they apply this, we have more income, and we can save a lot of labour,” said Ms Lien, who began planting coffee nearly 30 years ago. “Now, I see my coffee better developed, with better yields.” BLOOMBERG