this post was submitted on 30 Nov 2021
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international container shipments are actually super efficient, no? i've heard that the last few kilometres of delivery actually cause more emissions than the entire trip they take from mexico or some other country to wherever you live...
https://www.weforum.org/agenda/2020/02/avocado-environment-cost-food-mexico/
https://sustainabilitymattersdaily.com/10-bizarre-facts-that-describe-the-environmental-impact-of-avocados/
And container shipping (in general, maybe not specifically for avocados) is one of the worst polluters due to running on heavy oil & also makes up for a significant portion of world-wide annual CO2 emissions.
I'm not sure about container shipping, but I'heard the same, that even if of course one ship pollute much than one truck, the quantity they move around is so huge that efficiency is incredibly better. So sea mileage VS land mileage aren't one the same level at all.
I agree with water consumption though, that is a huge problem from what I understand.
The average efficiency (energy/km/kg) is better, but what's even better is to consume only locally-sourced and renewable materials :)
It's like the trick "question" green capitalists have about clean energy. Sure you can always make energy cleaner, but "clean" energy does not exist and the cleanest energy is always the energy you don't use. Same goes for transportation.
Actually, it depends. We did an analysis in one of my university environmental science classes about if you're living in Montreal in the winter, if you should buy produce from the subtropics (California in our analysis) or local produce. Well, local produce in Quebec is grown in greenhouses in the winter. And as it turns out, the carbon footprint to heat those things far outweighs everything else combined: including transportation. Like, you can get many times more produce shipped straight from California for the same amount of carbon emissions of a single stalk of local broccoli. The difference was so far beyond any margin of error that there was no way we could justify getting local produce no matter how much we tried (I'm pretty sure most people in our class went into it assuming local would win hands down).
The takeaway is: if it's really cold, food production isn't efficient and you might just be better off getting non-local food from somewhere warm.
@poVoq@lemmy.ml
That's a fair point: the source's location is not the only factor at play. I'm not familiar with your climate/environment, but i assume the native people have/had a diet tailored to their local environment, and that those greenhouses are meant to produce a capitalist "illusion" of abundance of varied/foreign crops. I'm curious if you have resources on that topic.
Also, from a more technical perspective, it's quite possible to heat greenhouses in an eco-friendly manner. The productions you're talking about are likely non-organic and not based on permaculture techniques. There are probably permaculture approaches to cultivating in the cold climates (though i'm unaware of them), but even using "conventional" (read "capitalist") techniques, producing compost from plant or animal (eg. human) waste is a good heat-generating process.
So while your study holds true, the balance in favor of imported goods is likely due to the types of foods consumed and to the industrial techniques used by industry and not due to the distance crossed by the goods itself. Do you agree with this interpretation?
We had a video a while ago on /c/solarpunk of someone growing citrus fruits in the middle of winter in the northern US in such an greenhouse heated with low-grade ground heat.
So it is definitly possible, but probably doesn't scale very well.
The real issue is that you can't expect to eat fresh produce in the middle of winter if you live in Canada. Food preservation for consumption in Winter is a well developed and scaleable technology.
Edit: https://lemmy.ml/post/56369 and specifically this video.
Did you also compare it to broccoli grown in summer and stored in a freezer?
Or for that matter, eating seasonal produce only?
The entire setup of comparing an artificially heated greenhouse in Canada seems specifically designed to make any alternative look good. How about growing produce on the north pole? I am sure the Canadian greenhouse will win against that /s
Freezer might be a viable alternative actually. Especially if you use a heat pump and use the "waste" heat to heat buildings in the winter. Or, even with greenhouses, a ground source heat pump that stores thermal energy in the soil in the summer and extracts it in the winter could potentially also work. Heat pumps can be up to 5x more efficient than resistive electric heat.
The thing is, to my knowledge, the only fresh produce available locally in Quebec in the winter is greenhouse grown because it's literally too cold for any edible plant to grow in the fields. Broccoli isn't special in this regard because nothing would be in season.
To be fair the assignment wasn't really meant to actually inform people what they should do. It was meant to test our ecological impact assessment and data analysis skills that we learned over the term, so they probably did pick a relatively simple example (still with real numbers though).