Food and Greenhouse Gases: An Ominous Future?

Post written by C. Will

In a world increasing in population and wealth, food production needs to be steadily increasing to meet the growing demand. However, a recent study in Nature Communications (discussed here) argues the rate of yield gains in wheat and rice production have plateaued, despite increased investment in R&D and education. Other studies (for example Ray et al. (2013)) have also found evidence that the current yield gain in major crops is insufficient to reach the estimated 60% increase in production required by 2050. If wheat and rice production have approached a yield ceiling it provides an ominous future for food security.

Previous increases in yield gain have been driven by investment in technologies that were largely one-time innovations and cannot be repeated. For example, innovations in genetically modified grains, major investment in irrigation infrastructure and increased use of fertilisers and pesticides saw steady increases in grain production.

Is livestock agriculture also at risk of approaching a yield ceiling?

New Zealand has experienced significant annual increases in livestock productivity for more than 20 years.  As we discussed in a previous post even with existing technology there is room for significant ongoing improvement as less efficient farmers catch up with those who are more efficient. In the short term, constraints on yield per hectare (intensity) are likely to be environmental (water quantity and quality) rather than technological (as noted by the Parliamentary Commissioner for the Environment’s report on water quality). Internationally, the enormous differences in livestock productivity suggested by differences in emissions per unit of output suggest space for considerable yield gains.  

Globally we need to be making all the efficiency gains that we can to resolve the food security problem and New Zealand has an important role to play in this through the livestock sector.