How to pronounce “brightening”(noun) in English

Same thing with cloud brightening. These cloud brightening ideas, you try brightening a few clouds, you see what happens; it doesn't work, you don't like the way it works, it's

And these classes of stars that do this brightening and faintening over time

problems like this, but one of the virtues of some of these systems is especially the two that I talked about most, which are cloud brightening and the sulfur particles, is that