Unless you've been avoiding the world wide web, you've definitely heard about Greta Thurnberg, a 16-year-old climate change activist from Sweden.

Unlike most teens, Greta has been traveling around the world to challenge people to protect the environment by reducing their carbon footprint. She's given speeches at various summits, including the United Nations Climate Action Summit, took part in protests and rallied youth to take action.

There is no denying that the young girl is working hard to save planet Earth, but some people are convinced it's because she's a time traveler (yes, you read that right) on a mission.

The conspiracy theory started on social media after a 120-year-old photo surfaced from the University of Washington's Special Collections archive. The photograph, which was taken by Eric Hegg in 1898, depicts three children, one of whom looks eerily like Greta, sifting for gold in the Canadian Yukon Territory.

"120-year-old photo sparks theories that climate activist & environmental heroine, @GretaThunberg , is, in fact, a 'time-travel' who has traveled thru time to save our planet! Wishing her all the best and success in her mission to save the Earth. We can use the help we can get!" wroteone twitter user.

In another tweet, a user joked that Greta most likely used an eco-friendly time machine.

The photo sparked confusion among some people, with many questioning how could Greta be from the future and past.

“To those saying ‘How can she be in the past if she’s from the future?!?’ Obviously, as a time traveller, she can travel to ANY time period. She obviously tried to go back 120 years, didn’t work, and now she’s here. Obviously!” explained writer Jack Strange.

Jack later added that "maybe trying to kill the person who would invent plastic" was the reason why Greta traveled back to the 19th century.

Some people, like comedian and broadcaster Tony Martin, are convinced the photo is fake.

"Photo is so fake it could have been made by Angus Taylor," he tweeted.

However, archivists at the University of Washington in Seattle confirmed that the photo is definitely real in a statement. It is part of Hegg's collection that was donated to the school over 50 years ago.

"As part of the UW Libraries Special Collections, the photo in question is an original," read the statement.

The university's digitized collection is searchable online, so it is likely that a facial recognition software mistook the girl in the photo for Greta.

The university has been getting more requests than usual regarding the image.  

“We’ve had about 15 to 20 requests just to talk about the photo, and we’re getting into almost the triple digits now, in terms of requests to use the photo,” Lisa Oberg, one of the archivists at the university, told the CBC.

The young environmentalist has not responded to the kerfuffle that the black-and-white photograph has caused as she's making her way to Portugal. Greta is traveling by sea on a zero-emissions yacht. She does not use planes because they create too much contamination.

What are your thoughts on the photo? Let us know in the comments!