Divide between ‘advocacy science’ and ‘real science’

One of the biggest challenges facing the agriculture sector globally is the divide between ‘advocacy science’ and ‘real science’, and the fact that the media is generally unable to tell the difference. This leads to headlines proclaiming that a new ‘study’ has quantified the enormous environmental impact of livestock production, for example, without any questioning of the objectivity of that study, or the validity of underlying assumptions.

A recent example was an announcement by the World Resources Institute (an international environmental advocacy group) of the results of a ‘study’ that identified that the change to higher protein diets in developing nations, and in particular the increase in beef consumption, was unsustainable given beef’s very large land, water and energy footprint.

The World Resources Institute (WRI) conclusion was that the only solution is to reduce consumption of protein, but in particular to reduce consumption of beef in the future. In support of this recommendation, the associated WRI report provided data and a number of graphs which identified the very significant environmental footprint of beef in comparison with other sources of food.

 


It is only on very close reading of the report that it becomes clear that graphs (such as the one shown above) display what is projected to be the marginal impact of additional consumption of each of the different types of food, with that marginal impact based on some highly questionable assumptions. For example, one assumption is that no future productivity gains will be made in beef production, and that any additional output will involve the clearing of vast areas of rainforest. As a result, the greenhouse emissions attributed to beef production dwarf that associated with any other form of food production, but a close examination shows that most of this is associated with the assumed mass clearing of forests that will be needed to accommodate the extra cattle. This assumption has been made despite that fact that average productivity gains in global livestock production range from 1.4–1.7% per annum, and that according to the US Department of Agriculture, most of the production growth over the past two decades has occurred without a major expansion in land use.

The water consumption figures used in the WRI report are similarly problematic. It appears that the assumption is that all the rain that falls on pasture used for beef production is ‘used’ by the cattle and there is no runoff, evaporation or drainage into the soil! This seems to be why the water consumption associated with beef production is so much greater than for dairy on an equivalent energy basis – the assumption being that most dairy cows are managed in intensive rather than pasture-based systems.

Perhaps the biggest problem with the above analysis is the underlying assumption that if land is not used for beef cattle production, it can simply be switched to crop production. This is clearly a ridiculous assumption, which anyone who has visited the extensive cattle production regions of Canada, the US, Brazil, Argentina and Australia would fully understand. This assumption underpins the major premise of the modelling, which is that plant and animal food production systems are substitutable on the same land. Another related major flaw is the assumption that if cropping areas were to be expanded globally, then the resulting input requirements to produce the additional crops on new land would be the same as input requirements for current cropping production area – an assumption that makes absolutely no sense. Expanding cropping areas to land that is currently marginal would result in a significant reduction in input-use efficiency in the new areas.

Meat & Livestock Australia and the CSIRO have carried out some very detailed analysis of the environmental footprint of different livestock production systems in Australia, and concluded that pasture-based systems are extremely efficient in terms of water use and greenhouse emissions relative to more intensive systems. They have also found that the environmental footprint of beef production (when accurately assessed) is substantially less than some of the more extraordinary claims that are made by environmental groups. Educating the media to understand the divide between the real science of organisations such as the CSIRO, and the advocacy ‘science’ of organisations such as WRI is a major challenge facing the livestock industries.

WRI (2016), Shifting diets for a sustainable food future, World Resources Institute, April, accessible at: www.wri.org

Image:  CSIRO