Climate Change Impact on Cocoa Production and Price in Ghana: A Systematic Review

Review
This paper investigates a significant issue: the impact of climate change on cocoa production, cocoa prices, and cocoa farmer welfare in Ghana.
It does so by reviewing relevant literature since 2016.

Unfortunately, the paper is largely unsuccessful in achieving its aims, stated as:

‘The study aims to examine the effects of climate change on Ghanaian cocoa production based on price instability, yield patterns and production areas. The study will further examine adaptation strategies employed by farmers to avoid such constraints. In this review, the study will project broader effects on farmers' livelihood, income stability, and poverty from the socio-economic effects. The study, lastly, aims to provide worthwhile insights into developing strategies and policies that can ensure the sustainability of Ghanaian cocoa production amid climate change.’

The paper has several shortcomings, as follows.

One, the introduction and literature review repeatedly states that climate change will harm cocoa trees and cocoa farmers, with statements such as this:
‘Climate change poses serious problems in Africa, where cocoa is a major export crop. ‘
But then we read that rather little is known about the impacts of climate change on cocoa in Ghana:
‘In spite of the economic significance of cocoa for Ghana as well as its international trade significance, empirical evidence of climate change impacts on Ghanaian cocoa production and price is still inconclusive.’
…
‘Apart from environmental change, the socioeconomic impacts of climate variability on cocoa farmers' communities have not been thoroughly examined.’

Throughout the paper there is a disjuncture between admitting that little is known for certain and many quite definitive statements about the effects of climate change on cocoa trees and cocoa farmers.

Two, a theoretical framing is offered drawing on sustainable livelihoods and vulnerability and adaptation. How these approaches have been used is not clear when results are presented in chapter four: in this chapter these framings and concepts are conspicuous by their absence.

Three, the method to select literature is not as clear as it needs to be. We read that ‘articles that are non-empirical, such as systematic reviews … are excluded.’ How many systematic reviews do not include empirical results? All the systematic reviews I have read, more than a dozen, are centred around reviews of empirical evidence. When we see the fifteen papers selected, they include at least one paper, Cedric et al. 2020, that seems to be a modelling exercise, rather than an empirical report.

The text admits that: ‘For accessibility reasons, the study included only open-access articles; articles with paid access or subscription-based articles are not covered in the review.’ But there is no discussion of the limits this imposes on the review: how many relevant papers were identified that were not examined because they were behind a paywall? How significant were these papers (quite often papers by experienced and skilled researchers appear in top-rated journals and sit behind paywalls: excluding such papers is to ignore highly relevant research.) [Why did the author not email the authors of articles behind the paywall to see if they could provide a copy of the paper?]

It is good to see a PRISMA diagram, but the criteria by which an initial list of 836 hits was reduced to 15 papers are not set out clearly and fully. Some 615 papers were excluded by an automation tool: which tool? And on what grounds did the tool exclude papers? Some 214 papers were screened: but how were these screened, and by which criteria were 199 papers excluded?

A tool was used to assess the quality of studies — ‘Mixed Methods Appraisal Tool (MMAT) 2018 version (Hong et al., 2018) was used to assess the quality of studies.’ — but how does this tool do its job? What markers of quality does it scrutinise and how? It is not necessary to give a detailed description of the tool, but the reader needs to have some idea of what it does and how.

Four, the results tell the reader too little. We learn that the reviewed papers indicate that climate change will reduce cocoa yields per hectare. That is plausible, but by how much are yields expected to fall? It’s hard to assess the importance of climate change for cocoa if we do not know that yields are expected to fall by, say, 10%, 20%, or 50%.

We learn that reduced cocoa production and more variable production will affect cocoa prices. Again, a plausible outcome, but by how much (and in what direction)? Volatility is all that is mentioned in the paper, but there is nothing on changes in average price levels. The possibility that farmers may see yields fall, but prices rise, leaving the effects on farm incomes ambiguous, is never broached.

The results chapter contains several statements that need to be explained and supported. Here’s an example on price effects:

‘The price volatility of cocoa, which is due to production volatility caused by climate, destabilizes farming communities even further.’
This is just too vague. What are the causal steps from production volatility to cocoa prices to farm incomes and farmer welfare? These steps need setting out and discussing,

We learn that some papers report farmers adapting to a changed and more variable climate; but again, we learn little about the extent — most farmers, a few farmers? — and degree of farmer adaptation — major adaptations or small changes? Again, the text is too vague in places; for example:

‘… in constituencies such as the Wassa East District, agriculturalists attempt resilience strategies such as crop diversification and shifting the planting times, but these efforts require resources which most lack, deepening their poverty (Kosoe et al., 2022; Yiridomoh et al., 2021).’

Diversification to which crops? Shifting the planting times of which crops from when to when? What resources do diversification and altered planting times require? And why would whatever responses farmers undertake deepen their poverty? Surely the responses would mitigate rather than deepen poverty.

Five, the paper is marred by odd arguments and expressions, For example,

‘Reduced production and crop losses caused by erratic weather conditions lead to food shortages, with cocoa being a source of livelihood and food for the majority (Amfo et al., 2020; Aniah et al., 2019).’
Cocoa as a source of food in rural Ghana? Has the author ever seen anyone in a village in Ghana eating cocoa (or its processed derivatives)?

Here are two quotes where quite what is meant is not so clear:

‘However, how climate variability is supported by different sources of capital, including natural, human, financial, as well as social capital, is not carefully examined (Waarts et al., 2021).’
I cannot imagine how different capitals ‘support’ (or ‘contribute to’) climate variability.

‘Climate change destabilizes the reliance of the nation on stable weather patterns, particularly rainfall (Siaw et al., 2023).’
Perhaps the intention of this sentence can be divined, but it’s a clumsy way to say that Ghanaians can no longer rely on stable patterns of rainfall.
Sometimes statements are too sweeping, such as

‘These diverse methods comprehensively analyze the socioeconomic impacts and adaptation strategies across various regions and contexts.’

Comprehensive: in what sense? Many of the fifteen papers reviewed cover no more than one or two districts, and deal with only one or two aspects of climate change and its impacts on cocoa. From what I read in this text, I would say the evidence is patchy, not comprehensive.
Six, at least one reference is missing from the bibliography: Famakinwa et al. 2023.

All told, this paper would need considerable revision to overcome the shortcomings listed before it could be published.

Note:
This review refers to round 1 of peer review.