this post was submitted on 20 Aug 2026
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Climate

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Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world.  About 1C of total warming.  Second chart:  about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability.  Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases.  About 0.5C of cooling with large error bars from SO2.

Recommended actions to cut greenhouse gas emissions in the near future:

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[–] captain_aggravated@sh.itjust.works 4 points 1 day ago (1 children)

They've been the standard around here for my entire lifetime. I'm in my first house that doesn't have one and when the air conditioner goes I'm replacing it with a heat pump.

[–] SaveTheTuaHawk@lemmy.ca 2 points 6 hours ago (2 children)

Air conditioner is a heat pump.

Well yes; at least where I'm from (the American southeast) an "air conditioner" will run only in one direction for cooling a space, a "heat pump" is the same technology with the addition of a reversing valve that can heat or cool the space. The HVAC technician I have on contract will understand exactly what I mean by "I want to replace my air conditioner with a heat pump." with no further elaboration.

[–] HerbGrower@slrpnk.net 2 points 5 hours ago (1 children)

Not all are reversible, and given they said when it goes I would assume it is an older one that can't do heating.

[–] captain_aggravated@sh.itjust.works 3 points 3 hours ago (1 children)

It is relatively new, installed in 2006 or so, alongside a condensing natural gas furnace. The furnace provides heat, the AC provides cool. It's working okay for now, when it's time to replace it I'll replace it with a heat pump system and retain the furnace for emergency and defrost.

[–] HerbGrower@slrpnk.net 3 points 3 hours ago (1 children)

Unless it gets very cold, probably no need to keep it. Had mine removed and I live in the UK. Not sure if there is anywhere that needs AC in summer and gets too cold for a heat pump in winter.

[–] captain_aggravated@sh.itjust.works 2 points 2 hours ago (2 children)

Not an option. Two reasons:

  1. Emergency heat is a legal requirement. A heat pump system without a source of emergency heat does not meet the North Carolina residential building code. That law was written back when AC was newfangled and untrusted, and Raleigh (and many other state capitols) didn't want families freezing to death because a compressor motor failed.

  2. American central HVAC systems are modular by nature, a heat pump system is designed to rely on the emergency heat system for defrost heat. Auto-defrost is accomplished by overriding the thermostat and commanding Emergency Heat ON, reversing valve to AC, compressor ON, fan ON. The ensuing sparring match between the heater and air conditioner pretty effectively defrosts the outdoor unit. And in the United States at least, by far the world's largest producer of natural gas, it's considerably less expensive to do that under methane power than electricity.

Defrost is a critical feature in my climate; winter hovers around freezing, often climbing to 1 or 2C during the day and dipping to -3 or -4C at night, and the relative humidity is ALWAYS high. Perfect icing conditions for a heat pump.

[–] HerbGrower@slrpnk.net 2 points 1 hour ago

Surely a heat pump can fail just as easily as a boiler? Log burner or even a biofuel fire kinda thing would be far more suitable as an actual emergency backup.

[–] SaveTheTuaHawk@lemmy.ca 1 points 1 hour ago

A heat pump system without a source of emergency heat does not meet the North Carolina residential building code.

I lived in an NC apartment complex. When the power went out, we froze. There was no emergency heat.