The arrival of El Niño, raising ocean temperatures, may push the price of your morning cup of coffee higher.

El Niño is a periodic warming of the Pacific Ocean, which has knock-on effects for weather across the world. This includes an influence on rainfall and temperatures.

For the world’s biggest producers of robusta coffee beans, Brazil and Vietnam, the impact could result in a drop in production.

In 2015, El Niño contributed towards a drought in Brazil’s Espirito Santo state, one of the country’s renowned producers of robusta beans.

Output in that season dropped by 40% due to the variable weather caused by El Niño.

Since this point, the country has invested heavily in features to help avoid such an impact, including new irrigation methods and larger water reservoirs to last through any dry spell.

Two types of coffee bean are widely used, robusta and arabica. Robusta beans typically have a higher caffeine content, while arabica are often used to create instant coffees.

If harvests of robusta beans drops again as it did during the previous El Niño cycle, we may see a fall in quality and a rise in price.

Prices are already at a 15-year-high due to worries about the imminent impact.