Issue 3
Straight into the science today!
In this issue, we’re going to mix things up a little bit. I have to be careful not to play a capital-J “Journalist” on the internet, but I also don’t want to waste opportunities to explore things more deeply. There was a scientific paper published recently that deserves some attention and, as I know one of the authors, I thought it would be useful to speak to him and ask some follow-up questions to give a bit more context. It’s an important paper for the wider future of coffee, and our global strategy for keeping it as a crop and a part of our cultures.
Let’s start with the paper itself:
"The Sustainability of Robusta Coffee Under Global Change—A Review" (full paper)
The lead author, Dr Aaron Davis, has discovered more species of coffee than anyone else in history, and is the Senior Research Leader of Crops and Global Change at the Royal Botanical Gardens at Kew. He has worked for 30 years in coffee science; has published over 150 peer-reviewed scientific papers, mostly on coffee; has spent 15 years studying and publishing on coffee and climate; and has made more than 100 fieldwork trips across the coffee belt to study coffee in the wild and in cultivation. He’s appeared on the YouTube channel before, notably in the video about the rediscovery of the fascinating species of coffee called Coffea Stenophylla.
We spoke for around 90 minutes. Talking to Aaron about coffee downloads so much information into my brain that it always leaves me feeling a little “I know kung fu?!”. A transcript of the part of our conversation covering the paper is available to my Patreon supporters. (We talked about much more, but most of it off the record.)
What does this paper say?
The quick summary is: Robusta is often presented as a climate-resilient species, and the solution to potential global coffee shortages as climate change hampers Arabica production. The problem is that no one seemed to have checked that this is actually true...
While robusta may be comparatively heat tolerant, there is more to climate change than just increased global temperatures and we're likely to see issues with weather impacting water availability throughout the year. Robusta doesn't do well with drought.
If this seems like something of a shocking oversight, you are not alone. When I asked Aaron why he wrote the paper he was quite direct,
"I was blindsided by the claims people were making about the future of coffee, and that the future was robusta because of its climate resilient properties. For coffee and climate change the focus has been on temperatures, but precipitation [rainfall] is also key, as is seasonality, i.e. when that rain falls. I've spent a large part of my life visiting wild coffee populations and coffee farms and the one thing robusta needs is a near-continuous supply of soil moisture; if it doesn't get that it suffers."
Changes to weather patterns and increasing unpredictability have been at the core of many issues that coffee has faced in the last 20 years, such as outbreaks of leaf rust. Rain falls when producers need it to be dry, but sometimes there's no rain for long periods, creating new problems.
This paper went a little further, and reading this gave me feelings of mild dread. A lot of robusta being planted is going into production systems that are actively making climate change worse. These systems involve heavy irrigation, synthetic fertilisers, and are often grown as monocrops without much in the way of shade trees.
"One of the other reasons I decided to write this paper is because there are plans to grow robusta in climatically unsuitable areas, with the use of irrigation. This may sound like a great idea. But in many cases irrigation is a short-term prospect, or is difficult to enact.
In Uganda, during drought years, we see robusta farmers renting equipment, buying fuel to run pumps, and finding the labor to do the irrigation work. This comes at huge cost for farmers. Over the long-term this is unsustainable, especially if the water for irrigation water runs out, and we have seen this situation in many countries.
One of the authors of this study, Akshay Dashrath, told me that last year they were using their large, purpose-built water storage pond, for the irrigation of robusta and to a lesser extent Arabica. When that dried up they went to their bore water, but the bore holes ran dry. I think there is a notion that irrigation is infinite, but it's not. When you travel around Africa and Madagascar, you see numerous failed short-term irrigation programs where the groundwater's gone, and this has negative implications for the local environment, and, most importantly the people that live there."
"More directly, the drought in parts of Central Uganda this year was devastating for robusta farmers. Many farmers had little or no capacity to irrigate, and lost their entire crop."
It's important to note that not all robusta is being grown in this way, but that this type of production system would likely be used if we need to scale up production very quickly. So you end up with a vicious cycle where climate change encourages intensified robusta production, which in turn encourages climate change...
Given the paper's motivation, I wanted to ask Aaron the awkward question about potential bias in a paper that supports a point of view.
"There is no bias, or advocacy, in the article. That’s not the role of science. In science one presents a hypothesis, and that hypothesis must be tested or supported in some way. Indeed, ones hypothesis may be ‘wrong’ but if your work is repeatable and testable you are forwarding knowledge and understanding. That’s not the case with the Internet, or other media, and unfortunately a lot of science, including coffee science, which can be of low quality, unethical or even fraudulent.
We reviewed over 160 peer-reviewed papers: I hardly think that’s cherry-picking. "
If you haven't started reading the paper, and the future of coffee is of interest to you, then I won't be at all offended if you close your email client and go and do a little reading. It is a well-written paper, and I think anyone can understand it.