At a panel discussion last month on food and climate change, there seemed to be a near consensus that we know how to solve the food sustainability problem and all that we need to work on are the personal choices and political will to get us there. I was the only panelist who seemed to have a contrary opinion. I suggested that there is still much work to be done before the world's growing population can be fed sustainably.
The panelists mentioned many of the characteristics that we normally associate with sustainable food: locally produced food, organically produced food, grass-fed/free-range animal products, and so on. But I am doubtful that any one of these, or even a combination of these, would make a large enough dent on, for example, climate change (arguably our most serious sustainability problem at present).
There may be good reasons for eating locally produced food -- but, as several studies have pointed out by now, it is generally not a very effective tool for mitigating climate change (Do food miles matter?). As for organically grown crops and grass-fed animals, our results so far suggest that there is no clear advantage on the climate front for these less intensive methods (Do organics have a lower carbon footprint?), unless soil carbon sequestration is included (Transitional soil carbon sequestration in agriculture). However, accurately modeling and calculating soil carbon accumulation is a difficult task that has not been done rigorously on a wide range of production scenarios (we and others are working on this). Given that soil carbon approaches equilibrium over time, the calculated benefit of sequestration in organic/grass-fed systems will likely be very sensitive to the time horizon selected -- including the starting and ending of the production period, as well as the assessment period -- and how the dynamics are modeled, in addition to the precise details of how the soil is managed in each system.
In my view, the best solution is likely to be a synthesis of many different things. It also needs to be scalable and customizable for different conditions worldwide. In order to think about a solution (actually a range of solutions) like this, it seems to me that we need to let go of strong attachments to terms like “local”, “organic”, etc., and replace them with them whatever works best under a given set of conditions.
If we move away from a rigid, binary classification of food production (organic, non-organic), we might agree that the solution space is more continuous and larger than previously thought and includes many more possibilities. Perhaps we could merge the best organic and conventional practices to create highly effective hybrid systems. Consider, for example:
· We are seeing organic crop yields in the range of 70-98% compared to conventionals. As an alternative, why not find ways to reduce and minimize synthetic inputs (for example, by using better technology to determine day-to-day plant needs) without sacrificing yield? Keeping the yields up will prevent additional land under natural vegetation from being converted to farmland – which should be good for preserving both biodiversity and the carbon already sequestered in soils/biomass.
· Recognize that currently “organic” production does not mean that it is entirely benign. Most organic systems use significant amounts of fossil fuels to run the farm, sometimes more than comparable conventional farms. Why not focus on reducing these unsustainable inputs and ultimately replacing them with renewable sources?
· A good hybrid system can still build soil carbon just as good organic systems can, depending on the organic materials applied and the tillage practices.
There may also be significant gains to be had from squeezing inefficiencies and waste out of food life cycles:
· Optimize food processing, cooking and refrigeration, and reduce energy consumption in all of these. We have seen significant emissions from these in several case studies. Sometimes the wrong sequence of energy-intensive operations is the culprit!
· Reduce food waste throughout the supply and consumption chain, and systematically compost whatever is still wasted -- wasted production is the main culprit, and landfilling the food waste adds insult to injury (Taking a bite out of food GHG emissions).
Consumer choice also needs to figure somewhere in the solutions, particularly as meat consumption increases worldwide. It may well be necessary to move from high-carbon proteins (beef, lamb) to lower carbon options (soy protein, poultry, pork, some seafoods).
The toolkit for optimizing food life cycles probably includes many other things that I have not touched on, such as hydroponic systems and vertical farms which have both advantages and disadvantages but could be applied selectively. If food sustainability is the goal, we should be prepared to cast a wide net and bring together tools and techniques that can make a real difference.
