Comment: Liberica coffee could help to future-proof coffee supplies

Liberica coffee — once ranked the second-most traded coffee crop species, but later regarded as a commercial failure — could re-emerge to help sustain coffee production in the face of a warming climate, argue Aaron Davis and colleagues in a Comment piece published in Nature Plants.

The demand for coffee has been growing, with global exports increasing by around 75% over the last 30 years or so. Coffee production currently relies on two types of coffee, Arabica (Coffea arabica) and robusta (Coffea canephora), which account for 55% and 45% of global production, respectively. Recent shortfalls in coffee stocks, either exacerbated or directly caused by the effects of drought in coffee growing regions, is likely to worsen given climate change-driven extreme weather events.

The authors suggest that there are three ways of adapting coffee farming in a changing climate: move coffee production to areas where the climate is becoming more suitable for cultivation; adapt coffee farming practices; or develop coffee crops better adapted to future climatic conditions. The authors propose that changing coffee crop type is likely to be the least disruptive and most cost-effective. They highlight Liberica (C. liberica) coffee, which during the latter part of the 19th century was grown extensively because it was high yielding, pest and disease resistant, and could grow in warmer, lowland locations unsuitable for Arabica. By the turn of the 20th century it had fallen out of favour, owing to inconsistencies in quality and issues concerning flavour and profitability.

Using museum collections and literature sources, the authors show that the initial introductions and selections of Liberica fruits and seeds were difficult to process (resulting in flavour quality issues), and thus not favoured by coffee merchants. The decline of Liberica was sealed by the introduction of robusta coffee at the beginning of the 20th century, and the upscaling of Arabica coffee. As well as the revival of interest in 'traditional' Liberica, there has also been a recent upscaling of excelsa coffee (a type of Liberica) in Africa. Excelsa has beans and fruits of a similar size to Arabica, and produces a mild, smooth coffee, of low acidity and bitterness, with roughly the same amount of caffeine.
“In a changing climate, Liberica offers (at the very least) the potential to grow commercially viable, and perhaps higher-valued, coffee under much warmer conditions (and at lower elevations) than Arabica,” the authors write, “and may offer improved climate resiliency over robusta.”

This press release refers to a Nature Plants Comment piece, not a Nature Plants research paper or article. Comment pieces are topical, authoritative Op-Eds pertaining to scientific research and its ramifications. The Comment was peer reviewed.