Answer: THUNBERG

"Thunberg" refers to Greta Thunberg, a Swedish environmental activist. She gained international recognition for her efforts in advocating for action against climate change. The clue suggests that she is the author of a book titled "The Climate Book," which is set to be published in 2022.

Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Activist "born at 375 p.p.m.," per her social media bio. Explanations are generated by AI and may be inaccurate.