It's been a busy year.

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Greta Thunberg has truly dominated environmental news over the past 12 months.

But all things must come to an end.

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As Greta has confirmed this week.

She spent 2019 learning remotely.

While traveling the world on a boat, naturally.

But it's all over.

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Thunberg is headed back to class.

She confirmed her move with an Instagram post.

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And it seems she's quite happy to return!

But where did it all begin?

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Starting one day in August 2018, a then fifteen-year-old Thunberg decided to skip school to sit outside Sweden's Parliament in Stockholm with the simple sign, “Skolstrejk För Klimatet" - translating to “School Strike for Climate."

Photos of the teen sitting in protest went viral on social media...

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And, suddenly, millions of people were inspired.

Within a year, her message had spread like wildfire...

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And millions of people all over the world had taken to the streets to fight against climate change.

It was a whirlwind year for the teenager.

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Thunberg attended numerous marches and protests all over the world and was even invited to the UN Climate Conference in New York, which she traveled to on a zero-emissions boat.

Her damning speech went viral...

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The activist blasted world leaders and politicians for their lack of action regarding climate change. "How dare you," she exclaimed. "I shouldn't be up here. I should be back in school on the other side of the ocean, yet you all come to us young people for hope. How dare you?"

And, fast forward to 2020...

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Greta Thunberg has become somewhat of a household name.

She was nominated for the Nobel Peace Prize last year...

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And was declared as TIME's Person of the Year for 2019.

She has risen to unprecedented levels of fame...

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And her unwavering commitment to saving our planet continues to inspire people to live more sustainably every day.

Thunberg has spoken to the Guardian, 2 years after she first took a stand on the so-called climate crisis.

The activist reflected on the whirlwind 2 years and the impact of her school strike movement.

"Looking back [over two years], a lot has happened."

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"Many millions have taken to the streets … and on 28 November 2019, the European parliament declared a climate and environmental emergency," said Thunberg.

But, it's been far from sunshine and rainbows, according to Thunberg.

"But over these last two years, the world has also emitted over 80bn tonnes of CO₂. We have seen continuous natural disasters taking place across the globe. Many lives and livelihoods have been lost, and this is only the very beginning."

She goes on to say we are "still in a state of denial."

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"When it comes to action, we are still in a state of denial. The gap between what we need to do and what’s actually being done is widening by the minute."

She continued:

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"Effectively, we have lost another 2 crucial years to political inaction."

Essentially, Thunberg believes we have done nothing to actually stop the problem.

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It's pretty damming stuff.

But it seems, for Thunberg at least, normality has to resume (at least a little).

"My gap year from school is over, and it feels so great to finally be back in school again!" Keep scrolling to read about a scientist who claims that cannibalism is the only answer to climate change ...