Swedish teenage climate activist Thunberg turns 18

Activist Greta Thunberg gestures in a photo which was posted with a message thanking her supporters for their well wishes for her 18th birthday, in this undated picture taken from social media. @GretaThunberg/via REUTERS

(Reuters) - Sweden's Greta Thunberg, who pioneered a global climate change campaign as a 15-year-old, turned 18 on Sunday and promised to celebrate by exposing "dark secrets" at her local pub.

"Thank you so much for all the well-wishes on my 18th birthday!," Thunberg said on Twitter.

"Tonight you will find me down at the local pub exposing all the dark secrets behind the climate- and school strike conspiracy and my evil handlers who can no longer control me! I am free at last!!."

Thunberg began a climate change campaign that swelled from a one-person school strike to a worldwide movement, drawing in millions of school children, as well as adults.

She criticised world leaders over climate change in a speech to the United Nations in 2019, has clashed with U.S. President Donald Trump, and last month called for urgent action five years on from the Paris Accord.

(Reporting by Richard Pullin; Editing by Raju Gopalakrishnan)