There is a german news from 28.12.2023 about UMTS/3G uses 1000 to 3000 kWh per transmitted Terabyte. 5G uses about 50kWh per TB,
https://www.heise.de/hintergrund/UMTS-Ausstieg-ist-gut-fuers-Klima-9583550.html
Would it mean that people transmitting many data per month should use a newer phone to save the environment? I don’t understand why FP doesn’t use this argument to sell newer phones.
3G/UMTS is phased out in most countries anyway, 4G/LTE is standard for data for quite a while now, so no need to advertise this ‚advantage‘ 
I have the need for this topic, at least since I want to save the environment in general. There are always better standards evolving, I don’t focus on the standards mentioned above, I want to understand the system in general.
I suspect that if people are using their FP2 for several years AND transfer many GB per month with mobile data (not using Wifi) maybe it could be better to replace the FP2 with a newer FP. Where is the breakeven? I don’t know.
For newer phones:
If a device supports 5G and a persons transfers 100GB/year for ten years it would result in 50kWh. I guess replacing a 5G phone with a newer phone wouldn’t be an advantage for the environment.
Offtopic but about thinking big: I think FP as a company has a bonus: they push the whole mobile phone industry at topics like replaceable battery, self-repairing the phone with modules and longer updates. This is great. Even if this small company does a mistake and something doesn’t work as expected they can add some environment saving efforts on their account that were done by other companies since FP pressures the industry.
In theory you’re right, however the FP2 already supports 4G (which in terms of energy is better than 3G) and as long as 5G is often used in non-standalone mode you’ll need 4G to be able to use 5G. Some other posts in this forum have already shown that even if the network supports standalone mode, FP5 doesn’t for all carriers. So that is something where Fairphone would have to do more work, I fear, before they could advertise this aspect.
Apart from that, offering greater network technologies usually hasn’t led to people transferring the same data via the better network, but usually the amount of data increases which eats up the benefits. Like a colleague stated a few years ago already when we talked about always new network technologies with more bandwidth and the question who needs that: In the past, people were kept ignorant by a lack of information. Nowadays this is done by an information overflow…
Pretty sure those still using a FP2 are not those using many GBs per month with 4G. In countries with no 2G and no 3G FP2s are now ewaste because of missing VoLTE.
You save probably on one side but create ewaste instead. Doesnt seem a climate friendly approach to me.