Conversely, the website Celebrity Net Worth estimates Thunberg’s net worth to be about $100,000 — that’s 10 times less than the $1 million that most other websites have reported. Greta Thunberg Climate Activist Net worth: $1 million (according to unreliable estimates) Greta Thunberg is a Swedish climate activist known for launching the Fridays for Future movement. Reports on Svante Thunberg’s net worth vary greatly — Famous Celebrities reports that it is $300,000, Quick Celeb Facts states that it is between $1 million and $10 million, and Famous Birthdays states that it is $1.5 million (the same website reported the same net worth for his wife).