Bananas have benefited from climate change, but they won’t in future

05 September 2019 | Adaptation

Climate change has been relatively kind to banana suppliers so far – but in the decades to come, friend may turn to foe. Temperatures are likely to get so hot that the annual production gains enjoyed by banana suppliers will begin to drop. And in some places, total banana yields will begin to decline.

Bananas are a staple crop for millions, and one of the world’s top 10 crops in terms of the cultivated area devoted to their growth and the calories they provide to the global population. For the past 60 years, annual yields have been increasing by 1.37 tonnes a hectare as the world warms, and now stand at about 10-40 tonnes per hectare.

But a new study by Dan Bebber at the University of Exeter, UK, and his colleagues suggests that as climate change continues, annual yield gains will begin to slump. By 2050, they may be down to 0.19-0.59 tonnes per hectare.

“Bananas can take it pretty hot,” says Bebber. “But some of our big suppliers are under serious threat, particularly in Latin America.” India and Colombia will be so badly affected that total annual banana yields will begin to fall, he says.

Bebber and Varun Varma of the National Centre for Biological Sciences in Bangalore, India, built a model of optimal conditions for banana production, based on databases from 27 countries stretching back to 1961, combined with temperature and rainfall records. Globally, the ideal average temperature for the crop appears to be 26.7°C, but the best level varies from country to country. Temperatures in the future were assumed to follow two of the UN climate science panel’s worst scenarios.

Bananas are cheap in high income countries, so producers are likely to be badly affected by any change in production yields. “For farmers, even small losses are a problem, particularly with bananas where the margins are tiny,” says Bebber. An estimated 400 million people eat bananas as a staple starch, so there are food security implications too.

Robert Caine at the University of Sheffield, UK, says developing countries may need to use modern technologies to combat the effects of climate change on farming.

Bebber says the recent arrival of a deadly fungus in Latin America, Tropical Race 4 (TR4), is a more immediate and severe danger to bananas. But he says the fungal threat could potentially be less of a problem, because it could be solved by cross-breeding or genetic engineering. Adapting to a hotter Earth, on the other hand, would require changing the whole physiology of bananas.


Source: New Scientist