Right in the middle of her big U.S. tour—she played New York Monday with Lil Wayne and had the sore throat to prove it last night—Nicki Minaj surprised the packed house during Bid To Save the Earth Tuesday night at Christie’s Auction House in New York with a performance. Sitting in the green room about an hour before her super-secret set was scheduled to begin, we talked with the singer about everything from preshow jitters (she gets them) to preshow routines (green tea and honey)—and how she’s making her own bid to save the Earth.

What are you wearing tonight? Is it one of your favorite designers?
Yes, it is—it’s Alexander Wang. It’s all black, of course, and I knew I needed to get my green on, so that’s how I came up with the green-and-white hair. I have a lot of designers I like right now; I really like Donatella Versace. She sent me a few beautiful things recently to consider wearing to the Grammys and, even though I ended up wearing Givenchy, I believe in supporting women. I’m all about the girl power.

Why did you decide to get involved in Bid to Save the Earth?
I know that a lot of my fans are young and I know I have the power to influence and inspire them by my own actions. I thought that if I got involved in a cause that I felt was important, then maybe they would take the time to research it and find ways they could get involved and make a difference. It’s good to shine a positive light.

If you could enact one rule to help the environment, what would that be?
I think there are a lot of things we could be doing better. I know when I see one of those big, gas-guzzling cars on the road, I cringe because I can’t help but think of all the more efficient alternatives. You don’t need that kind of car. So maybe that would be my rule, that people have to drive cars that are more environmentally responsible.

We Googled you while we were walking here. Do you Google yourself?
No, not any more. I used to when I started out just to see if I was on it, but then I realized that reading blogs is a lot more fun when you aren’t being written about—there is so much gossip and so many rumors. The other day, I read that I was pregnant and I thought, That’s crazy! Who is writing this stuff? I don’t need to read that.

What are three things you can’t live without?
Pink lip gloss, pink blush, and black mascara.