To enumerate 128 bits in 35 years you would need to make 3e29 attempts per second.
Current bitcoin miner can provide efficiency of 19 000 000 MH/J or 19e12 H/J. If we would assume bruteforcer can perform with the same efficiency, we would need 1.6e16 J/s = 16 000 TW.
Current humanity energy output is something like 17 TW.
Yeah, botched my numbers, sorry. I saw that the hash rate of the current Bitcoin network went up to 2^93 hashes per year, and then I managed to pretend 2^128/2^93 = 35, instead of 2^35.
With your numbers if humanity dedicated all its energy to brute forcing a 128/bit key for a year it would have a ~0.1% chance of finding it. I guess that's a pretty good argument that no one is going to even try it in the foreseeable future.
Current bitcoin miner can provide efficiency of 19 000 000 MH/J or 19e12 H/J. If we would assume bruteforcer can perform with the same efficiency, we would need 1.6e16 J/s = 16 000 TW.
Current humanity energy output is something like 17 TW.