While it is definitely beneficial to consume locally produced fruits and vegetables, it might not have a lower carbon footprint than frozen counterparts that are shipped from further away. And this is even truer for anything grown out of season.
There are many variables to consider, including refrigeration costs, out of season growing, and transport. But the biggest factor of all for determining the true carbon impact of your fav fruits and veggies is most likely food waste.
The current global estimate is that about 1/3 of all food goes to waste, taking into consideration everything from processing, supermarket spoilage, and poor household food management. When it comes to fresh produce, this number is certainly higher and might be as much as double. Fresh produce has a short shelf life and if it doesn’t rot in the supermarket, it often rots on the counter or in the fridge at home.
Frozen fruit and vegetables are believed to have a lower carbon footprint mostly because waste is cut down at all levels — less spoils in the grocery store and less spoils at home. The end result is significantly less waste to the point that it makes up for emissions associated with refrigeration and transport. This might highlight the current food waste problem better than anything else. But that’s not the only benefit to using frozen produce, especially when compared to out-of-season fresh fruit and veggies. Frozen produce is grown seasonally, reducing the need for out-of-season energy-intensive growing, and frozen produce can be shipped by lower-energy methods. Both of these benefits further reduce the overall carbon footprint of frozen fruits and veggies.
One word of caution, however: there is a limit to the benefit, so you can’t just store your frozen goods indefinitely. If frozen produce is stored for longer than six months 100 days, the carbon footprint of refrigeration begins to overtake that associated with the food waste.
Important: After 100 days, the cooling process for frozen produce begins to outpace the energy-intensive canning process for canned fruits and vegetables. Canning is another alternative to the waste associated with fresh produce. Be on the lookout for more info on carbon impacts from using canned goods.