Lance Bass says fatherhood goes by "too quickly."

The 43-year-old pop star welcomed twins Alexander and Violet with husband Michael Turchin via a surrogate in October 2021 but "cannot believe" that he has been a dad for a whole year already as he reflected on his children's milestones.

He said: "It does go by way too quickly. I cannot believe it's been a year. It's just nuts. Right now, my daughter finally took her first step, so that's been something that's so nice.My son said his first word a month ago, but he hasn't said it again. So all those little milestones are just so precious.

Meanwhile, the former NSYNC star is "very passionate" about environmental causes and claimed that people are now "paying attention" to the issue because it is something that "cannot be ignored".

He told PEOPLE: "In the last few years, people are actually paying attention because you can't ignore that climate change is happening. Now that everyone knows it's real, people are listening, and we're able to really get the messages out of what we can do to try to combat it. Environmental justice is going to be the big thing for the younger generation, and I feel so happy to know that they are in it for the right reasons. They grew up learning about climate change, something that I didn't even know about 15 years ago.

"But this young generation, this is what they live and that's just their future and their kids' future and their grandchildren's future. So they know it's so important to take care of it right now, or we're not going to have a great planet for our kids to live in."