I found this sentence below in one essay but I do not understand the structure.

"Plant-derived plastics, biodiesel, wind power and solar power are all things that are a step in the right direction, but the powers that be need to enforce the limits on CO2 emissions for the polluting industries in their countries for these to be effective."

What does "that be need" mean? And why it does not say "that are needed". I am confused mainly by the structure that follows the comma ("but the powers that be need to enforce the limits on CO2 emissions for the polluting industries in their countries for these to be effective"). Where is the verb?

If someone could explain it to me, I would be so grateful.