Is there a way to trade Pokemon in black now that the wifi service is disconnected?

Question

Not infrared

Answer 1

Nope, unless you use infrared

Answer 2

No, you cannot trade Pokemon in Gen 5-. As long as if they keep the Wi-fi disconnected, you won't be able to do anything internet/Wi-fi related stuff, such as battling and trading. If you want to know why they shut it down, click here.