Thunberg, who turns 17 in January and who is known for her blunt, straightforward speaking manner, has urged immediate action to address what she describes as the global climate crisis.

Thunberg was lauded by Time for starting an environmental campaign in August 2018 which became a global movement, initially skipping school and camping out in front of the Swedish parliament to demand action.

"In the 16 months since, she has addressed heads of state at the UN, met with the Pope, sparred with the president of the United States and inspired four million people to join the global climate strike on September 20, 2019, in what was the largest climate demonstration in human history," the magazine said.

"Margaret Atwood compared her to Joan of Arc. After noticing a hundredfold increase in its usage, lexicographers at Collins Dictionary named Thunberg's pioneering idea, climate strike, the word of the year," Time said.

Thunberg continues to beat the drum, saying in Madrid on Wednesday that business and political leaders are misleading the public by holding negotiations that are not leading to real action against warming temperatures.

Australian Associated Press