Research from Climate Central suggests human-caused climate change is contributing to higher latte prices worldwide, including coffee-obsessed Australia.
"Bean belt" countries responsible for 75 per cent of global supply - Brazil, Vietnam, Colombia, Ethiopia, and Indonesia - experienced an average of 57 extra days of coffee-harming heat than would have been expected without climate change.
The two dominant coffee plants - arabica and robusta - are both vulnerable to extreme heat, with temperatures above 30C considered extremely harmful for the former and suboptimal for the latter.
In high temperatures, crops come under stress that can reduce yield, bean quality and leave plants more disease-prone.
Climate Central vice president for science Kristina Dahl said nearly every coffee region was experiencing extra days of extreme heat.
"Climate change is coming for our coffee," Dr Dahl said.
"In time, these impacts may ripple outward from farms to consumers, right into the quality and cost of your daily brew."
Drought in Brazil has already been weighing on bean supply and feeding into higher wholesale prices.
Arabica and robusta coffee bean prices almost doubled from 2023 to 2025, according to International Coffee Organisation figures, with prices reaching an all-time high in February 2025.
Higher prices for raw beans translates into a more expensive cup of coffee in Australia, though the final price tag also captures wages, rent, energy and other costs that businesses say have also been elevated.
Nationwide, the cost of an average flat white rose about 10 per cent between 2023 and 2025, according to Square's digital payments numbers retrieved from cafes.
As well as fuelling coffee-harming heat, climate change can also alter rainfall patterns and make pest and disease management more challenging.
Global warming has been linked to the spread of one of the crop's most notorious pests - the coffee berry borer - into higher-altitude areas.
Coffee farmers, who are predominantly small-scale operators, do have methods available to them to adapt to rising temperatures and changing rainfall patterns.
But the Climate Central analysis says small-time farmers are receiving just a fraction of the finance they needed to adapt to climate change.
Producers such as Chief Rafael Mopimop Suru have been embracing sustainable coffee-farming methods with success.
The farm on Sete de Setembro Indigenous Land in Rondonia, Brazil, leverages agroforestry - planting crops and livestock alongside tree - to produce its Amazonian robusta coffee.
Planting trees with the crops helps shade them from extreme heat and rain, and also produces leaf litter that fertilises the soil and locks in moisture.
The agroforestry operation has received little in the way of finance for climate adaptation.
"We have never been able to access rural credit," Mr Mopimop Suru said.
"It's a lot of bureaucracy, they arrive here without understanding our reality, they talk and then leave."
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