Purdue’s Sub-par Palm Research

A group of researchers from Purdue University published a paper last week that claimed RSPO or sustainability certification for palm oil is no better than non-certified palm oil.

The paper has received some international attention from newspapers such as the UK’s Independent, which went on to imply that all palm oil is bad.

The basis for this claim is that all RSPO concessions record high levels – around 38 per cent – of tree loss. This statement is also made:

In none of the concessions under investigation, both certified and uncertified, did we detect zero tree removal in 15 years.

There are two massive flaws in the paper that allow them to draw such a conclusion.

First is the data they used.

The researchers were using Global Forest Watch (GFW) data as their primary source of information for tree cover loss, which looks at a 15-year period, 2001 to 2016. The GFW dataset is brilliant, but GFW goes to great lengths to point out its limitations: one, it cannot distinguish between tree cover in a plantation (including oil palm) and natural forest; two, that it does not distinguish between tree cover loss in a plantation and tree cover loss in natural forest and; three, that even when a plantation regrows according to a planting cycle, the area is still counted as loss.

On this last point, GFW again goes to great lengths to point out that it’s not possible – using their methodology – to subtract forest gain from forest loss and come up with a ‘net deforestation’.

GFW also points out that ‘tree loss’ and deforestation, i.e. conversion of forest to other uses, are different things.

In other words, all tree loss comes up as tree loss, even if it’s being replanted.

Second is their apparent ignorance of the palm planting cycle.

Most readers would be well aware that palms hit peak productivity between 7 and 18 years of planting. The optimal replanting time is around 25 years, depending on a number of localised environmental factors, but the ability to finance replanting is also a consideration, as well as the price for FFBs.

So, over a 15-year study period, it’s quite reasonable to assume that a large proportion – let’s say 40 per cent – of palms would be cleared and replanted.

It should also be noted that the researchers don’t appear to factor in replanting in their paper; and nor do they acknowledge the limitations of the GFW dataset.

Here’s an example.

The Jengka Triangle plantations were established in the 1980s by FELDA near Temerloh. GFW maps show that there was significant tree loss through 2001 to 2015.

Why would there be tree loss in an area that was established as a palm plantation around 30 years prior?

It is because replanting was taking place. The same GFW data shows significant tree cover gain through the same period. This was because the seedlings grew to maturity in around 3 years or more.

There are several disappointing aspects to this paper.

The paper appears to have been written with a predetermined outcome in mind. The authors conflate ‘tree loss’ with deforestation. In our opinion, doing so is probably either disingenuous or incompetent.

If the researchers have, in fact, somehow managed to distinguish between plantations and natural forests inside or outside plantations, they should probably tell the GFW researchers. This is something they’re keen to do accurately.

Also disappointing is that it was published at all. ‘Science of the Total Environment’ may not be the world’s most highly rated journal, but where are the standards? Purdue is a prestigious university, associated with the respected Big Ten Conference, and known for its great academic credence. This underdeveloped research hasn’t done anything for Purdue’s good name.

In October this year, a group of academics managed to have four hoax papers published in various academic journals. One received a special award. Is this paper that far off?

Finally, the coverage the paper has received in international media indicates that some journalists will happily let shoddy research get headlines – and clicks. Is this fake news? Probably. The Independent has said RSPO is yet to respond with a comment. We’re looking forward to what they have to say.

The public debate about palm oil is full of disinformation. Purdue University and The Independent have just added to it.