wattmatters
Solar Wizard
It's just not that simple I'm afraid.Shopping at local farmer's markets or buying locally produced goods from stores helps to reduce the carbon footprint in obtaining those foods.
In many cases buying local produce may in fact be worse from a carbon emissions perspective than an imported item. Such an assessment needs to be considered on a case by case basis.
e.g. is it better to buy a tomato from a local heated greenhouse using more fertilisers and water pumping, or one imported from a location with a climate and land suitable for growing tomatoes? In pretty much every case the latter is far better even though it involves more packaging and transport to get it to you.
As a general indicator, on average, transport and post processing of food represents only about 10% of the carbon cost of the produce. IOW just because food is locally produced does not automatically make it a lower carbon choice. There are other much more important factors.
The biggest emissions culprits (combined contribute 80% of emissions) are:
- land clearing / change of land use, especially deforestation
- methane emissions from animals and rice production and
- the use of fertilisers and farm machinery
So, per item, was the local produce better from a land use perspective, from a fertiliser consumption perspective, from a farm equipment perspective (e.g. small scale is almost always less efficient/more embedded emissions per unit)?
Even from a transport perspective local may not actually be better even though it is physically closer. Large scale production reduces the transport element per item significantly, vs local production being trucked in small batches many times over. Big distribution and logistics operations in most cases are very efficient.
Of course there are going to be many occasions when buying local is better from an emissions perspective, and there are many other good reasons to buy local. I'm not against buying local. It's just we can't make a blanket assumption that it is actually better from an emissions perspective.
Reference for some data on emissions for food produce:
Science | AAAS
www.science.org