The study, which rated the effects on emissions of different carbon emission mitigation strategies at 25%, 50%, 75% and 100% implementation rate, found that while moving towards ‘flexitarian’ diets would certainly help reduce greenhouse gas emissions, it is far from enough.
A big player in climate change
The global food system is one of the world’s biggest players in emitting GHG and thus contributing to climate change, being responsible, according to the study, for 21–37% of the world’s GHG emissions.
This will be bad for the food system itself, meaning systematic crop failures, diluted nutrients in foods and a cataclysmic impact on smallholder farmers in the developing world.
Using the recommended diet from the EAT-Lancet report, which includes only moderate amounts of meat, eggs, dairy and fish, the study analysed the potential GHG emissions globally if this diet was implemented.
It also analysed what the world would be like if we continued along similar dietary lines as presently (in a ‘business as usual’ scenario).
Conversely, the study compared the GHG emissions for a situation where food waste and loss continued business as usual, and if they were reduced by 50% by 2050.
Next, they analysed the affect of GHG-emissions reducing technologies on emissions. For each technology, they analysed the amount of emissions it was capable of reducing, pairing each technology with the emissions type it targeted, as well as analysing the capabilities of carbon dioxide removal (CDR) technology.
Diets are not enough
While having a significant impact, the study found that changing diets alone would not be enough to bring about net negative GHG emissions if food production methods did not change at all, as the emissions reduced by a global change in diet to flexitarian would not be as large as the business-as-usual global emissions from the food industry.
However, the study suggests that such a dietary shift would, in any case, be unlikely without significant changes in the way food is produced.
Technology as saviour?
While not all technologies assessed made a substantial change to GHG emissions (new seafood farming techniques, such as trawling management, for example), many did.
For example, using additives in feed to reduce methane had a substantial affect, as did applying biochar to cropland to reduce nitrous oxide emissions. Agroforestry, the combination of forests with agricultural land, also had a significant impact. Furthermore, all of these can be implemented without the need to drastically change global supply chains.
The combination of technology that reduces GHG emissions and technology that takes it out of the atmosphere was shown, unlike changing diets, to be able to get the food system to net negative GHG emissions when implemented fully, even with business-as-usual diets.
However, due to the vast amount of variables that could conflict with this scenario being fully implemented, the study made sure to measure the effect of a combination of diet and technology, and found that the ideal scenario would be the implementation of both flexitarian diets and GHG-reducing tech.
Sourced From: PLOS Climate
'Model-based scenarios for achieving net negative emissions in the food system’
Published on: 6 September 2023
Authors: M. Almaraz, B. Z. Houlton, M. Clark, I. Holzer, Y. Zhou, L. Rasmussen, E. Moberg, E. Manaigo, B. S. Halpern, C. Scarborough,X. Gen Lei, M. Ho, E, Allison, L. Sibanda, A. Salter