CO2 is going to be neutral for the peels. You're just transporting it from where the oranges grew to where they were dumped. The CO2 benefit is purely from the trees and other biomass that grow where they wouldn't be growing before.

As for methane, that's a good question. Orange peels are better than most things because the limonene inhibits methane producing bacteria. But you'd still get quite a bit in the deeper piles (that produce the anaerobic conditions needed for methane production).

Spreading them out more would help, but might interfere with the beneficial effects.

The orange peel is going to decompose and produce CO2 either way. Methane is produced when there is not enough oxygen available while decomposing, which certainly seems a possibility if it's dumped in big piles.

You're getting downvoted but it's a reasonable question if posed in good faith. The tl;dr is that there are really a few options for what could happen to those orange peels:

(1) Landfill burial

   (1a) Without methane capture and use: Produces methane, relatively high short term warming potential.
   (1b) With methane capture and use: Ends up as CO2 after burning the methane.

(2) Composting (this approach)

   (2a) Mostly aerobic: Produces CO2
   (2b) Mostly anaerobic: Produces methane

A deep pile that is never turned will decompose anaerobically, resulting in fairly undesirable methane. A shallower pile or one that is mixed well will result in mostly aerobic decomposition. The aerobic decomposition will produce CO2 but not huge amounts of it. Each hectare of land could absorb something like ~8 tons of CO2 per year; with 7 hectares, the CO2 emitted by composting 12t of oranges is going to be dwarfed by the new vegetation. After a few years when you're growing big trees, the rate of CO2 absorption might rise as high as 20-30t/year/hectare in costa rica's environment. And this is probably an underestimate, as the soil amendment of the orange peels seems to have stimulated faster regrowth than would have happened otherwise.

And perhaps more to the point: There isn't really a purely "no co2" way of disposing of organic matter other than perhaps burying it at the bottom of a deep mineshaft (but the co2 or methane will be produced anyway). Landfilling it is strictly worse - you still get the decomposition products, _or worse_ because you'll mostly get methane, but without producing useful soil byproducts.

Overall this project is a huge win on a carbon perspective and a waste reduction perspective.

Indeed. I've been doing that for a quite a number of years now.

I just put food waste and some other compostable stuff outside -- in a pile, on the ground. Currently, that pile is in a place where autumn leaves tend to gather naturally.

And in that pile, it all composts. It turns last week's bean soup into next year's hot pepper harvest.

It's not zero-effort but it's very close. I'll have spent more time writing this comment than I have on any aspect of composting over the last several months.

Later on, to use it in the garden, I just... use it in the garden. I scoop aside the top layer with a shovel and take whatever is beneath it. The plants don't seem to care that the composting method is slow and lazy, or that a portion of it might be somewhat unfinished.

(Now, to be sure: Home-scale composting can have a great deal of optimization applied. Bins, aeration, deliberate introduction of red worms, careful management of moisture, temperature monitoring, whatever -- the sky's the limit. But I have enough hobbies, and I'm not trying to market it as a product or win a race here. This method keeps up with my household's output just fine and doesn't take up much room at all in my tiny-ass yard.)

Rats and other undesirables can be attracted to compost. So it is probably best to use a composting bin, if you can.

Also try to mix in some brown/carbon (leaves, shredded paper, cardboard etc) with your green/nitrogen (food scraps, grass cuttings etc), otherwise it can become a stinky swamp (anerobic).

Ngl I didn't know there was another way to compost. The whole idea is to just throw vegetable waste into a pile and let it turn into dirt, isn't it?

They saw it as corruption, basically. Here's a contemporaneous article: https://apps.sas.upenn.edu/caterpillar/index.php?action=retr...

> TicoFrut, which is 98% Costa Rican-owned, charges that the environmental services contract is little more than a permit for improper disposal of its foreign-owned competitor's waste. TicoFrut President Carlos Odio says Del Oro should be compelled to build a proper waste-disposal plant just as his company was forced to do in the mid-1990s amid allegations that orange waste from its juicing plant was polluting a nearby river. So TicoFrut teamed up with a high-profile environmentalist and radio host, Alexander Bonilla, and enlisted the support of two prominent congressmen and a few citrus growers in denouncing the Del Oro project. However, none of Costa Rica's conservation groups joined in the attack on Del Oro.

[...]

> One of the ministers they cited was the acting environment minister at the time, Carlos Manuel Rodriguez, who signed the contract on behalf of the government. Rodriguez, an attorney, denied having sat on Del Oro's board but acknowledged representing the company while working in a law firm contracted by the CDC, Del Oro's British owners. The other official, Agriculture Minister Esteban Brenes, acknowledged having sat on Del Oro's board but denied any involvement with the contract.

> TicoFrut also claimed foreign employees of the CDC and, by extension, Del Oro, had received diplomatic immunity as a sweetener to invest, and could thus act with impunity.

> The Costa Rican Ombudsman's Office conducted its own review and declared the contract illegal. In its non-binding ruling, the ombudsman's office said no official studies had been done on the viability of the orange-waste experiment, and that due process had not been followed before the contract's signing

My guess is that Del Oro would have a competitive advantage in its waste disposal costs.

I guess tico fruit is just an asshole. Being sued is usually bad. If you can sue your competitor even better.

It's the kind of question that I'd rather see answered by an ecologist than a judge!

It depends on where the hike is: Dropping an orange peel in a humid, temperate, low-elevation place is vastly different than a desert, high-alpine, tundra or other environment where organics take a long time to decompose.

life's too short for friends like that