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Comment by makerofspoons | Hacker News Reader

Drawdown.org ranks refrigerant management as the number one way to fight climate change: https://www.drawdown.org/solutions-summary-by-rank

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Awesome site I never heard of, ty!

Worth noting that coming in at #4 is the one we can all contribute to right away -- https://www.drawdown.org/solutions/food/plant-rich-diet. The amazing thing is your dietary choices impact those around you as well so you end up having a > 1 person impact!

My partner answered a TON of vegan questions, worth checking out if anyone is interested or has questions: https://www.wikiful.com/@MsKapow/the-vegan-inquisition

That statistic only true when looking globally. If you look at U.S. statistics, greenhouse gasses from meat is only 3% of total. Plant farming represents 6%.

If you want to make the argument that cows eat plants, while true, often they spend the majority of their lives eating grass. Feed lot stage is generally near slaughter. In addition, many farms use by-products of things such as sugar production to feed animals (molasses, beet pulp pellets, etc...). The only reason corn is used is because it is the single most subsidized crop in America.

This is not a clear cut statistic at all.

I’ve poured through the EPA tables on the contribution of agriculture production to greenhouse gases, and the high level number is misleading. Typically estimates look at emissions directly contributed from agriculture, but they separate out a ton of linked factors. Like, the production of petrochemical fertilizers are not included in the “agriculture” emissions category; only the emissions that are released in using them to farm. Then there’s transportation emissions, etc, all in their own categories. (It makes sense to look at agriculture as a whole, since so much of it is geared towards feeding animals...)

Then there’s the opportunity cost for all the land that is used to farm annual crops for animals. That land could be regenerating healthy soil, and capturing carbon.

Bottom line, the official numbers aren’t by far an accurate picture. Animal agriculture, even in America, is a huge piece of the climate puzzle.

Not to mention that the thing which really matters is impact per calorie provided and, most importantly, there is a 50x range in the amount of calories that plants provide per unit of input. So the real advice should be: replace high cost/calorie foods with low cost/calorie foods. Which could mean replacing berries and leafy green vegetables with chicken as much as it means replacing filet mignon with sweet potatoes.

Short of digging a pit and lining it with salt, is there anything that a regular person not actively involved in research about this can do?

I'm specifically curious about things that can be done in apartments or condos, where flexibility is low, but I'm also interested tangentially in solutions for (detached) home owners living in sparser settings with more control.

The big issue is what happens to the refrigeration gases at end-of-life because they have such high global warming potential. The units are nominally hermetic, so they should last their entire life without leaking much refrigerant. If you have an old AC unit, try to dispose of it responsibly by not sending it to a landfill. A responsible recycler/disposal facility will reclaim the refrigeration gases for recycling or disposal.

There really aren't good alternatives available for purchase right now. Almost all units sold today will contain gases which have low Ozone Depletion Potential but still have high Global Warming Potential (~2000-9000x as potent as CO2).

There is a heat pump hot water heater available from Sanden using CO2 (ironically) as a refrigerant, which has a GWP of 1. It is pretty darn expensive.

This whole area is really a place we need some startup innovation. Both products that use something other than HFCs for refrigeration and some kind of business model or non-profit which will have the goal of getting old units out of the hands of consumers responsibly.

> If you have an old AC unit, try to dispose of it responsibly by not sending it to a landfill.

Considering someone stole the AC unit off the roof of the house next door to me in the middle of the night (it was a rental property and nobody was currently living there).

You know - meth.

Anyhow - something tells me there might be some valuable material inside an AC unit, so why anyone would just take it to the landfill (unless it has an A/C recycling program - some do)...

Copper tubing in the condenser?

(Or, you know - meth...)

Since your comment is on the context of the USA, looks like that’s about to change: https://www.coolingpost.com/world-news/us-approves-hydrocarb...

For things like window units and fridges, this will at least allow one of the better drop-in replacements for HFCs to be on the market. The charge size limit of 150g will still prohibit things like central AC units and mini splits, unfortunately.

People are so worried about a little isobutane or propane in their refrigeration devices but we have constant pressure tubes forcing methane into many of our homes at 60psi. HCs would be great refrigerants and I think we can deal with the flammability...

The natural gas pressure at a stove inlet is supposed to be something like 0.25 PSI, not 60 like in the underground service lines. A pool boiler might need slightly higher, but in general the pressure in the building lines is very low.

https://inspectapedia.com/plumbing/Gas_Pressures.php#Natural...

CO2 is not an efficient refrigerant, its critical temperature is 31C, but CO2 is darn cheap

You can also operate the CO2 in a 'trans-critical' mode which gets around some of the issues of the low critical temp. This is done by using a gas cooler to cool supercritical fluid in place of the typical condenser.

There aren't really many good alternatives that are cheap, have very low GWP (less than 100), are non-toxic and non-flammable. HFOs are probably the closest to this, but even these are often mildly flammable and typically quite expensive (often > $50/kg).

Over here it seems CO2 refrigerators are increasingly common for supermarkets, warehouses etc. AFAIU it can be made about as efficient as HFC's, but the up front cost is higher due to higher pressures. OTOH CO2 is cheap, as you say, and there's no risk the next iteration of the F-gas legislation will make your new investment EOL.

Seems like it would be easy to fix within any particular jurisdiction by requiring some deposit on any new fridge which could be redeemed when it was disposed of.

That would effectively just be a tax on fridges since they last so long.

Fight (lobby, voice your opinion, etc) at your local level to preserve (and expand) trees in streets. Fight against parking lots replacing greenery, fight for the opposite. Ask your municipality to spray down roads in the evenings when it's really hot (if your area does not suffer from drought). Learn to use morning cool air to cool down the flat (depending on where you live). Don't AC your house to (extremely) low temperatures. Get good shades.

Spend less money. That can mean buying less stuff (or used stuff), or it can mean not paying other people to do stuff for you (learn how to fix/build things your self, eat out less, etc.).

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