Kenya's celebrated coffee under threat as farmers hit by climate change

The crop has been part of these lush highlands since the late 1890s, when British colonial settlers introduced it.

Now, the area is famous for its unique, top-rated coffee.

Growing the berries is labour intensive - picking, pruning, weeding, spraying, fertilising and transporting the products.

"Coffee requires your full-time concentration, especially when it starts to bloom," Mr Macharia said.

"From that moment up until the day that you are going to harvest - those six months, your full-time job is on the farm."

A coffee tree is a huge investment for cash-strapped farmers, as it can take four years for the fruits to mature.

The price of a single cup of coffee in a chic European café, typically $4 (£3.20), highlights a stark disparity when compared to the earnings of many Kenyan coffee labourers, who make at most $2.30 a day.

Edita Mwangi, who harvests coffee cherries on the red earth hillside overlooking the processing plant, confirms this.

"They don't know the poverty we suffer. You have to struggle day and night just to survive," she said.

With four children depending on her, Ms Mwangi works six days a week, earning about $1.40 a day.

She has to walk 5km (three miles) to reach the farm where she works.

Farmers feel the trading system between Kenya and Europe - the world's largest coffee market - has been stacked against them for many years.

But now, a new threat looms, jeopardising farmers' ability to make a living - climate change.

Coffee trees are extremely sensitive to small differences in temperature and weather conditions.

They also need specific climatic conditions like humid temperatures and ample rainfall to grow.

"Climate change is a major challenge for our coffee farmers," says John Murigi, the chairman of the Komothai Coffee Society, which represents 8,000 coffee farmers like Mr Macharia.

Coffee can only be grown in the "coffee belt" - tropical regions around the world in areas typically located at an altitude of between 1,000m and 2,000m.

In recent years, climate change has led to a shortage of global coffee supplies and an increase in the price of coffee due to drought and crop failures in several key coffee-producing nations such as Brazil and Vietnam.

A survey by Fairtrade International, the organisation behind Fairtrade labels, found that 93% of Kenyan coffee farmers are already experiencing the effects of climate change.

The coffee industry in Kenya is a key source of employment, providing jobs for an estimated 150,000 people.

To protect the industry, coffee farmers in areas like Komothai are experimenting with climate adaptation techniques, such as planting trees to provide extra shade for the coffee plants.

Mr Murigi said it is only through addressing both the climate and economic challenges faced by Kenyan coffee farmers that they can have a sustainable future.

However, coffee farmers like Mr Macharia are pessimistic about the industry's future.

"Right now, as things stand, I don't think any parent wants their child here farming coffee," he said.