Over recent years there has be a sustained push to implement ecolabelling, in order to inform consumers of the environmental credentials of the food products they purchase, and presumably to influence those consumers not to buy environmentally bad products. But one of the major proponents of the ecolabelling push has decided to abandon its efforts, as realisation sinks in about how difficult and uncertain the calculations are in order to provide the data for labelling systems.

UK supermarket giant Tesco has announced that it has decided to abandon its push to implement carbon labeling for all its product lines, citing the complexities of calculating the necessary data, and the lack of take up by other retailers as the key reason for its decision. While not stated in the announcement, it is also a fair bet that consumer data was not providing any indication that the labelling made any difference to purchase decisions.

Those familiar with the complexities (and data gaps) associated with trying to put carbon numbers on products would not be surprised by this announcement. The carbon footprint that can be calculated for any product depends largely on the rules used in the calculation, and the boundaries that are applied to a production system. As recently published research on the carbon footprint of Australian egg production highlights, even homogeneous products such as hen eggs can have dramatically different 'footprints' depending on small changes in production systems, feed sources and energy sources. The calculations also rely heavily on default data for certain inputs, that may not be appropriate depending on specific situations. 

It is also apparent that there is ample opportunity for carbon footprint data to be manipulated or incorrectly reported, with prime examples being long-running controversy over the carbon footprint of ethanol, and the highly questionable data utilised by proponents of the 'less meat means less heat' mantra.

Perhaps the Tesco development signals its time for a bit of a rethink on this issue. Its all very well to publish carbon and other environmental numbers, but if those numbers lack credibility (as many do that have been published to date) then it wont take long for the general public to become quite sceptical, and to regard the whole ecolabelling concept as a bit of a joke.