Swedish teenage climate activist Greta Thunberg turns 18

Greta Thunberg turned 18 on Sunday (Jan 3).
Greta Thunberg turned 18 on Sunday (Jan 3).PHOTO: REUTERS

STOCKHOLM (REUTERS) - Sweden's Greta Thunberg, who pioneered a global climate change campaign as a 15-year-old, turned 18 on Sunday (Jan 3) 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!" Ms 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!!" Her tongue-in-cheek Tweet has been liked 171,000 times.

Ms 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 United States President Donald Trump, and last month called for urgent action five years on from the Paris Accord.