Page 211 - Climate Change and Food Systems

chapter 6: global climate change, food supply and livestock production systems: a bioeconomic analysis
figure 8
Climate change impacts on net trade by 2050 in ‘000 tonnes. (ALMILK – bovine and small ruminant milk, RMMEAT – bovine and small ruminant meat, MGMEAT – pig and poultry meat)
reduced precipitation could lead to a 25 percent decrease in milk production under the LPJmL yields without CO2 fertilization, compared with the current climate scenario. The climate effects seem to be the most uncertain in the Near East & North Africa and in sub-Saharan Africa. For instance, in the Near East & North Africa, the change in ruminant meat production attributable to climate change varies by +/-20 percent, depending on the yield scenario.
In sub-Saharan Africa, the effects are the most uncertain and potentially the most severe; ruminant production could increase by 20 percent but it could also decrease by 17 percent, and all yield scenarios except for LPJmL with CO2 fertilization would lead to monogastric meat production falling by more than 30 percent.
The model scenario analysis confirms this approach confirms that there is a generally positive relationship between changes in crop yields and monogastric production, and between changes
in grass yields and ruminant production. This link is the strongest with respect to changes in grass yields and ruminant meat production. This can
be explained by the fact that grass represents a substantial share of the meat ruminant diet, and that adaptation options in grassland management are limited.
The relationship between grass yields and changes in milk production provides a good illustration of the complex interactions present in the global livestock sector. For instance, Oceania shows two cases of counterintuitive behavior
with this respect. On the one hand, grass (and crop) yields decrease in projections by EPIC without CO2 fertilization and milk production increases, and on the other hand, grass (and
crop) yields increase in projections by LPJmL with CO2 fertilization, and milk production decreases. Oceania is projected to be the second largest milk exporter by 2050; therefore, its local production depends on the supply in other regions. Under the EPIC scenario without CO2 fertilization, supply of milk from Europe – which is projected to be the largest exporter by 2050 – decreases, as does milk production in sub-Saharan Africa and North America, and this gap is filled by the increased production in Oceania (Figure 8). Similarly, under yields projected by LPJmL with CO2 fertilization, milk production increases in some of the importing regions – such as South Asia and sub-Saharan Africa – which reduces the demand for milk exports from Oceania, and leads to reduced production. However, another reason why change in grass yields is not a good predictor for change in
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