A study stating that coconut production poses a threat to biodiversity five times greater than palm oil has set off a heated debate on social media, Science reported on 17 July.

Critics of the paper, published in Current Biology on 6 July, accused the authors of promoting dubious statistics and attempting to whitewash palm oil production.

“Dear logging companies, should you ever need to justify your destructive and extractive (illegal) activities in the Amazon and South East Asia, or protection against nature conservation NGOs [non- governmental organisations] or legal action, please refer to the following paper in @CurrentBiology,” University of Warwick primatologist Adriano Lameira wrote in one of a number of sarcastic tweets about the paper.

The study said around 12.3M ha of land were used to cultivate coconut palms, compared with 18.9M ha for oil palm. However, coconut oil had a much better reputation, according to lead author Erik Meijaard, who directs Borneo Futures, a consulting company based in Brunei, and chairs the Palm Oil Task Force of the International Union for Conservation of Nature (ICUN). Consumers associated it with more tropical islands and white sandy beaches than with the deforestation linked to planting oil palm groves, he said.

That reputation wasn’t deserved, Meijaard and others wrote in the two-page document. The authors calculated the number of species under threat from the cultivation of seven vegetable oil crops – according to IUCN’s Red List of Threatened Species – and divided those by the global oil production for each crop. Coconut threatened 20.3 species for every 1M tonnes of oil produced, they reported, while for olive and palm oil, the figures were 4.1M and 3.8M species respectively. For sunflower oil, the figure was 0.05.

According to the paper’s supplementary information, the number for coconut oil was actually 18.3, not 20.3. When Science asked about the discrepancy, co-author Jesse Abrams of the University of Exeter acknowledged that the calculation contained an error that the authors would ask the journal to correct.

“The outcome of our study came as a surprise,” Meijaard said. The reason was that coconuts were primarily grown on tropical islands, “many of which possess remarkable numbers of species found nowhere else in the world”, he added.

Some species had already become extinct because their habitat had given way to coconut palm, he explained.

The perception of the environmental impact of different oil crops often appeared to be impaired by ‘shortsightedness and double standards’, according to the authors.

However, critics of the study said it was misleading. Meine van Noordwijk, a senior research fellow at the World Agroforestry Centre, said the vast majority of the species threatened by coconut palm lived in small island nations that together produced only 8% of global coconut oil output, with 80% of coconut oil produced in India, Indonesia and the Philippines.

Excluding the small producers from the analysis would have yielded a very different number, Van Noordwijk said, noting that coconut palms were often planted alongside other crops making it difficult to evaluate the crop’s harm.

Sheherazade, a field biologist who heads Tambora Muda Indonesia, an organisation for Indonesian young conservationists, agreed. “We need a finer spatial analysis to discern which crop drives deforestation,” she said.

Some critics also pointed to a potential conflict of interest with Meijaard receiving funding from an Indonesian palm oil company and from the Roundtable for Sustainable Palm Oil. However, Meijaard said he had been transparent about his funding.