Lots of things take 2% and that’s the problem - you can keep breaking down consumption into finer and finer categories, to find that all those fine categories each only take a small percentage of the total.
The problem is everything, all together. All the 2%s each need to take action in their own way.
This is the opposite, though. In order to cobble together a number that seems even remotely problematic they had to combine several things that are weakly related: all IT workloads, plus all wireless networks. They also needed to express it in terms of global electricity, instead of global primary energy, because it is absolutely dwarfed by fuel burned for transport. Finally, this is a consumer that can be trivially decarbonized.
Compare private passenger cars which are ~12% of global CO2 and there are no practical ways to decarbonize that.
Never trust a mathematician wrt trivial | left as an exercise to the reader :
"One day Shizuo Kakutani was teaching a class at Yale. He wrote down a lemma on the blackboard and announced that the proof was obvious. One student timidly raised his hand and said that it wasn't obvious to him. Could Kakutani explain?
After several moments' thought, Kakutani realized that he could not himself prove the lemma. He apologized, and said that he would report back at their next class meeting.
After class, Kakutani, went straight to his office. He labored for quite a time and found that he could not prove the pesky lemma. He skipped lunch and went to the library to track down the lemma. After much work, he finally found the original paper. The lemma was stated clearly and succinctly. For the proof, the author had written, 'Exercise for the reader.'
The author of this 1941 paper was Kakutani."
Also, in some cases various types of obstructionism. I've heard several stories (including some from my home state) of wind farms being fought against tooth and nail, even in cases where the negative impact is somewhere between tiny and minimal (e.g. the only town nearby would see them as 1" tall on the horizon). Some of this is no doubt thanks to campaigns from incumbent energy providers and other underhanded methods like weaponization of environmental regulations.
The problem is everything, all together. All the 2%s each need to take action in their own way.