Agreements might not yet be brewing amongst negotiators at United Nations climate talks, but tea certainly is.

It's one of the clearest reminders that the climate summit — COP29 — is hosted by Azerbaijan. Attendees who roam for miles within the indoor venue have ample options to take a pit stop for sugar and caffeine: shops stack high mountains of pastries with sugary, nutty pakhlava and cardamom-tinged, crescent-shaped shekerbura. At Azerbaijan's country pavilion, women in Baku's traditional dress pour the warm drink for visitors.

All of it, like daily life in the city outside, revolves around tea — which climate change threatens around the globe. As world leaders descend on the capital city of Baku for climate talks, researchers who study tea report that in some regions around the world, tea cultivation could decrease by over half as rising temperatures, drought, heavy precipitation and erosion batter tea plants and the land they grow on.

Scientists are studying ways to improve tea varieties and preparing for a future where some tea production moves north, along with many other crops hard hit by climate change.

Tea "is a source of livelihood for our region; especially for the local people, for tea producers", said Keziban Yazici, a professor who has been studying the effects of climate change on tea, speaking in Turkish.

“We need to take the necessary precautions against climate change to make this product sustainable."

Her team has been working on developing drought-resistant tea varieties at their university in Rize, Turkiye, one of the major tea-producing areas in the Caucasus region. Yazici travelled to Azerbaijan this spring to initiate further cooperation between the countries — which have many similarities in tea culture and growing — on preparing tea crops for the threat of climate change.

The perilous future of this beloved drink serves as a reminder that if the world fails to meet the global warming goals set in the Paris Agreement, many places around the world stand to grieve not just lives and livelihoods, but also treasured elements of cultural heritage.

“Culture and the future has to be aligned," said Fatima Fataliyeva, the senior sustainability director for the COP29 operation company, who was responsible for the design of the Azerbaijan pavilion at the venue. “My mom taught me this, so I will (teach) my kids, so it doesn't disappear.”

Fataliyeva described the importance for her team of including Azerbaijani culture at the venue. The first thing that comes to your attention, she said, is tea.

From an early age, she learned that drinking tea symbolised hospitality and respect. Tea is for drinking with family and friends, in the home and out on dates. It's central in gossiping and matchmaking, for grandpas playing chess, on festivals and in times of mourning. People drink it from pear-shaped glasses called armudu that keep the bottom of the tea warm while cooling the top, sometimes served with a wedge of orange or lemon and a lump of boiled sugar.

“When you are happy, you drink tea. When you are sad, you drink tea,” said Levent Kurnaz, a professor who studies climate change and ways of combatting invasive pests that are likely to cause increasing harm to tea plants.

Kurnaz attended COP29 in part because he saw it as an important way to communicate about climate change — a topic he says isn't talked about as widely in Turkey and Azerbaijan but that is already slamming the few subject-matter experts in the region with a vast array of problems, present and future, in fields ranging from agriculture to immigration.

“Climate change will affect this region seriously,” Kurnaz said, especially for farmers, many of them women, who have grown tea all their lives. “They don't have a clue what to do when tea production goes sour. But at some point it will."

Azerbaijan is 25th on the list of top crude oil exporting countries and one of the birthplaces of the oil industry, one of leading sources of planet-warming carbon dioxide emissions. The country is planning to hike its fossil fuel production over the next decade to meet demand from Europe, and their oil production has been a point of controversy since the beginning of this COP.

But President Ilham Aliyev said earlier this year that the country is an phase of transition toward clean energy, while maintaining the world continues to need fossil fuels to develop in the foreseeable future.

For ordinary people as well as producers, climate change and choices about food and drink are intertwined. That's evident to Rauf Shikhaliyev, who owns a vegetarian and vegan restaurant in Baku called De Rama, also included in the COP29 venue food court. He felt it was “very important to participate" at the climate talks because his project of creating a vegetarian restaurant was “highly linked to climate change,” he said.

He added that after years in the restaurant business, he's seen the tea culture firsthand: before they order food, many locals will first order tea.

It's fitting for the UN: “Tea drinking makes people get kind of united,” he said.