The 16-year-old Swedish climate crisis activist became the youngest person to be chosen by the magazine. The tradition of choosing Person of the Year was started in 1927.

Before this announcement, she addressed to a UN climate change summit in Madrid and said that the next decade would play a significant role in defining the planet's future.

She also urged the world leaders to stop using Public Relation (PR) method to avoid real action to combat climate crisis.

The magazine said it named her for this honour for sounding the alarm about humanity’s predatory relationship with the only home we have ... for showing us all what it might look like when a new generation leads.

Last year, the teenager, who stopped attending school, started a weekly protest outside the Swedish Parliament, which become a worldwide environment saving movement that became popular with the hashtag #FridaysForFuture.

This year, she was nominated for the Nobel Peace Prize of the year.

According to the magazine, she became the biggest voice on the biggest issue on the planet this year.

The earth’s existential crisis found one in Greta Thunberg. Marshaling “Fridays for Future” protests throughout Europe; thundering, “How dare you!” at the world’s most powerful leaders in her viral UN speech; leading some 7 million climate strikers across the world in September and tens of thousands more in Madrid in early December, Thunberg has become the biggest voice on the biggest issue facing the planet—and the avatar of a broader generational shift in our culture that is playing out everywhere from the campuses of Hong Kong to the halls of Congress in Washington, Edward Felsenthal TIME’s Editor-in-chief wrote in his article on why Thunberg is the Person of the Year.