Food Security and Climate Change: What does the 5th IPCC Assessment Report Tell Us?

SEI expert Bill Pritchard unpacks the food security chapter in the latest IPCC report

Image sourced: World Bank Photo Collection

It was reported in advance that food security would comprise an important part of the much-anticipated 5th Assessment Report of Working Group II of the Intergovernmental Panel on Climate Change (IPCC). The final draft of the report, released on the 31st March 2014, contains a lengthy (82 page) discussion of this issue (Chapter 7). Those pages provide a comprehensive stock take of (what Donald Rumsfeld might have called) the ‘known knowns’ and ‘known unknowns’ of this difficult and complex issue.

As the Chapter authors acknowledge, food security did not figure highly in the 4th Assessment Report (see section 7.1.3). If nothing else, this was because of the rudimentary knowledge base that was present at the time it was released, in 2007. The modelling of climate-agriculture interactions was scarce and relatively crude, and the implications of climate change for the broader food system not well conceptualised. Both these areas of research have flourished in the seven years between reports. However, important gaps remain still, and these ‘known unknowns’ provide the most interesting and challenging areas with which researchers need to grapple.

To begin, however, what does the Chapter tell us that we didn’t know before? Of course, it is a synthesis of research findings, not a compilation of original data. Yet the breadth and esteem of its authorship means that its interpretations carry authority. Through its carefully qualified wording, conclusions are couched in terms of low/medium/high ‘confidence’, ‘agreement’ and ‘evidence’. For the IPCC, words are bullets, to be used with precision and deliberate intent.

Low Crop Yields

Most importantly, the Chapter affirms that climate change will hold mostly negative implications for crop yields (‘high confidence’) (section 7.4.1). This issue was raised in the 4th Assessment Report but with less overall evidence. In particular, the question of carbon fertilisation (the apparent effect of higher atmospheric CO2 in stimulating crop growth) was not fully resolved. In this Report, the authors dispatch any suggestion of potentially offsetting carbon fertilization effects with ‘high confidence’ (section 7.3.2). In addition, they suggest that climate change will “more likely than not” depress crop yields by more than 5% by 2050 (section 7.4.1). The potential to address these losses through expanding agriculture into forest lands is undermined by poor soil nutrient content and infrastructure deficits (section 7.4.1). This is exacerbated by the maladaptive effects for climate mitigation of large-scale replacement of forest cover for agriculture.

Climate Shocks

There is increased certainty about the effects of climate volatility on agricultural production and practices. Heat stress through temperature spikes will be more common, with half of the area sown to wheat in the Indo-Gangetic Plains displaying markedly higher vulnerability (section 7.3.4). Climate shocks resonate especially within smallholder agriculture, where the absence of crop insurance translates into risk-adversity (section

The increased confidence in which the IPCC has reported these effects should establish new benchmarks of consensus upon which the climate change-food security debate can be advanced. We now have concrete evidence that a hot world is a hungry world, as Oxfam’s influential report on this issue was titled. Yet as important as this conclusion is, of greater significance is the reluctance of the authors to affirm many more elements in this topic area. This is highly revealing, as it indicates the huge task still in front of researchers.

Known Unknowns

There are three broad areas of ‘known unknowns’. The first is the intersection of agricultural production with markets. Since the 4th Assessment Report, world food prices have undergone a rollercoaster ride. The authors seek to untangle the role of climate within this tumultuous period, however a clear answer cannot be found. Looking forward, the authors propose with ‘medium confidence’ that global food prices will have risen substantially by 2050, but this conclusion is built from the consensus of different models seeking to connect climate with agricultural production and market responses. As the authors coyly acknowledge, “the choice of economic model matters as least as much as the choice of climate or crop model” (section 7.4.4).

The second known unknown relates to adaptation. Anticipated effects of climate on food production hinge on the extent to which farmers are able to accommodate and account for a changing climate by adapting their behavior. The Chapter provides considerable evidence of agricultural adaptations occurring currently (section, but also notes the considerable barriers to adaptation faced by many farmers across the world (section Put simply, this is a black box that is impossible to incorporate within climate-agriculture modelling. It requires extensive, on-the-ground assessments of farmer behaviour. The work of the Climate Change Agriculture and Food Security Research Program has extended our knowledge of these issues, but our knowledge here remains the tip of an iceberg.

Finally, while the bulk of the Chapter concerns itself with the implications for food production, this is not the same as food security. At the outset, the authors acknowledge that the task of producing food is just one element in the food security challenge. Equally important are questions of food access and utilisation (the nutritional qualities of food). However, the analytical strength with which these broader dimensions of food security are integrated into the climate change debate remains tepid. The Chapter acknowledges that climate change will have important effects for non-farm rural livelihoods and the propensity for political conflict, but does not make progress in quantifying or analytically assessing these processes (section 7.4.4). Likewise, the Chapter admits that there is urgent need to repair data gaps with respect to how climate change intersects with the broader food system, inclusive of processes, distribution and consumption (section 7.6).

The 5th Assessment Report provides a major addition to global knowledge about the connections between climate change and food security. In exposing both what is known, and what is still to be researched, it highlights the important need for sustained, coordinated and multi-disciplinary work in this field.

Dr. Bill Pritchard is an Associate Professor in Human Geography specialising in agriculture, food and rural places. He is also an executive member of SEI heading up the Food, People and the Planet node. You can read more of Bill’s writings on food security in his latest book, ‘Feeding India’.