The link between durian and climate change: IPCC report says how we use land affects planet

The growing appetite for durians is contributing to climate change, with forests in places like Malaysia being cleared to make way for durian plantations.
The growing appetite for durians is contributing to climate change, with forests in places like Malaysia being cleared to make way for durian plantations.ST PHOTO: HEDY KHOO

SINGAPORE - Global hunger for staples like rice is fuelling the release of planet-warming emissions, a new scientific report released on Thursday (Aug 8) shows.

Closer to home, the growing appetite for other delicacies is also contributing to climate change, with forests in places like Malaysia being cleared to make way for Musang King durian plantations.

The Intergovernmental Panel on Climate Change's (IPCC) special report on climate change and land shines the spotlight on how the way humans have been using land is affecting the planet.

Agriculture is a major focus of the report authored by 103 scientists from 52 countries.

Agriculture and climate change

Growing food to feed the world contributes to climate change in two main ways: Emissions of methane and nitrous oxide from livestock and plantations, and land conversion.

The IPCC report said that ruminants - a group of mammals including cows - and the expansion of rice cultivation have been major contributors to the rising concentration of methane in the atmosphere.

Methane, one of the most potent of planet-warming gases, is released by flatulence from the animals and from microbes in flooded paddy fields.

 
 
 
 

But agriculture also contributes to climate change when forests are cleared to make way for plantations and pastures.

Natural ecosystems such as forests function like carbon "banks". They take in carbon dioxide (CO2) from the atmosphere in a process known as photosynthesis, converting the heat-trapping CO2 into organic carbon that is then stored in their roots, vegetation and leaves.

But when these natural ecosystems are cleared for plantations or pastures, the land loses its ability to capture and store carbon.

In Malaysia, for example, forests have been cleared to make way for durian plantations, The Star newspaper reported in October 2018. Demand from China for the king of fruits has resulted in forests on a hilltop in the Hulu Sempam area being cleared, the article said.

Professor William Chen, the Michael Fam Chair Professor and director of the Nanyang Technological University's (NTU) Food Science and Technology Programme, said: "In addition to farming of staple crops like rice, farmers tend to shift to more economically lucrative plantations including the recently reported durian monoculture in Malaysia. The competition with traditional crop farming will drive deforestation, thus contributing to higher greenhouse gas emissions."

The durian dilemma

Ironically, the destruction of forests for durian plantations could impact yields of the crop. This is because durians cannot self-pollinate and require animal pollinators to help them do so.

But when the forests disappear, so do forest-dwelling animals like the fruit bats - important pollinators of the durian, research by Malaysian conservation group Rimba has shown.

Durian flowers have both male and female parts. However, pollination only occurs when the female part of the flower receives pollen from a male part of a different flower, said Rimba president Sheema Abdul Aziz.

Rimba's research indicated that fruit bats from the Pteropodidae family are one of the most efficient natural pollinators of durian trees.

However, these animals face many threats. The fruit bats known as flying foxes (Pteropus hypomelanus and Pteropus vampyrus), for example, are already threatened by hunting, said Rimba. Further loss of their forest habitats would affect their numbers even more - and reduce their effectiveness in durian tree pollination.

Said Dr Sheema: "Deforestation for durian plantations not only causes the destruction of critical habitat for wide-ranging animals such as tigers, elephants, primates and hornbills, it also reduces the numbers of the very pollinators that are necessary for durian fruit production."

Rimba is proposing that durian trees be grown in a way that would ensure the survival of pollinator communities. This includes avoiding deforestation by growing durian trees on previously tended agricultural land instead of forests, and by practising low-impact, organic farming.

"This will also help to guarantee the long-term longevity and viability of our local durian industry," said the conservation group in a press statement.

The durian case study exemplifies one of the findings of the IPCC report, which pointed out that sustainable land management could help reduce the negative impact of climate change and other stressors on ecosystems and human societies.

Durian lover Lindsay Gasik, who runs the Year of the Durian blog, said: "Without bat pollination, the farmers will need to hand pollinate, which with Malaysian-style agriculture is almost impossible or very, very labour intense. So it's in the farmer's best interest to take care of wildlife habitat."

 
 
 
 

She added that durian lovers who care about the environment should support small, boutique farms which keep their old trees and practise pesticide-free farming.

The durian case study exemplifies one of the findings of the IPCC report, which has pointed out that sustainable land management could help reduce the negative impact of climate change and other stressors on ecosystems and human societies. 

IPCC Working Group II co-chair Hans-Otto Portner highlighted this link between the changing climate, biodiversity and human well-being during a press conference on the latest report on Thursday (Aug 8). 

He said ecosystems and biodiversity are already being impacted by the changing climate. Humans, he said, are part of the natural ecosystem, relying on nature to provide ecosystem services. 

And just as how climate change is affecting the ability of nature to cope, it is also making some areas of the planet increasingly difficult to live in. He added: “We may also be losing habitat in the future depending on climate conditions. All of these... indicate that urgent and near-term action will take us to a better future.”