Greta Thunberg, the 16-year-old Swedish climate activist, made headlines this week after her impassioned speech to the United Nations on the perceived inaction of countries governments to address climate change. The speech sparked sharp responses online from the left and right along with Twitter trends like #HowDareYou. She has even been made into a meme thanks to a snapshot of her piercing look given to President Donald Trump.

But who is the young climate change activist?

Thunberg was born in Stockholm to Malena Ernman and Svante Thunberg. Ernman is an accomplished opera singer and member of the Royal Swedish Academy of Music. Svante Thunberg is an actor and son of Olof Thunberg, a Swedish actor and director. Beata Thunberg, 14, is Greta Thunberg's younger sister.

Greta Thunberg was also diagnosed with Asperger syndrome, selective mutism, and obsessive-compulsive disorder at the age of eight. She has embraced these diagnoses and has even referred to her Asperger’s as her “superpower.”

Greta Thunberg’s rise to prominence began in 2018 with a school strike to encourage action on climate change. Her strikes quickly spread via social media and would inspire waves of school strikes across the world demanding world leaders take steps to address climate change. She had also asked her parents to reduce their carbon footprint, which led to the family giving up flying and adopting a vegan diet. However, it did force her mother to give up performing opera internationally.

“I am doing this because nobody else is doing anything. It is my moral responsibility to do what I can,” Greta Thunberg told the Guardian in a 2018 profile. “I want the politicians to prioritize the climate question, focus on the climate and treat it like a crisis.”

In August, she dominated headlines by making a voyage from Plymouth, England, to New York City to attend U.N.’s 2019 Climate Action Summit. Greta Thunberg made the trip in a 60-foot racing yacht modified with solar panels and underwater turbines. The voyage began Aug. 14 and ended on Aug. 28., culminating with her fiery speech Monday.

Greta Thunberg is also confirmed to be attending the U.N.’s 25th Climate Change Conference in Santiago, Chile, that begins Dec. 2.

Greta Thunberg has seen her profile grow. She recently appeared on "The Daily Show" and has 2.2 million followers on Twitter. 

Here is a transcript of her speech at the U.N.'s Climate Action Summit.

"My message is that we'll be watching you.

"This is all wrong. 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!

"You have stolen my dreams and my childhood with your empty words. And yet I'm one of the lucky ones. People are suffering. People are dying. Entire ecosystems are collapsing. We are in the beginning of a mass extinction, and all you can talk about is money and fairy tales of eternal economic growth. How dare you!

"For more than 30 years, the science has been crystal clear. How dare you continue to look away and come here saying that you're doing enough, when the politics and solutions needed are still nowhere in sight.

"You say you hear us and that you understand the urgency. But no matter how sad and angry I am, I do not want to believe that. Because if you really understood the situation and still kept on failing to act, then you would be evil. And that I refuse to believe.

"The popular idea of cutting our emissions in half in 10 years only gives us a 50% chance of staying below 1.5 degrees [Celsius], and the risk of setting off irreversible chain reactions beyond human control.

"Fifty percent may be acceptable to you. But those numbers do not include tipping points, most feedback loops, additional warming hidden by toxic air pollution or the aspects of equity and climate justice. They also rely on my generation sucking hundreds of billions of tons of your CO2 out of the air with technologies that barely exist.

"So a 50% risk is simply not acceptable to us — we who have to live with the consequences.

"To have a 67% chance of staying below a 1.5 degrees global temperature rise – the best odds given by the [Intergovernmental Panel on Climate Change] – the world had 420 gigatons of CO2 left to emit back on Jan. 1st, 2018. Today that figure is already down to less than 350 gigatons.

"How dare you pretend that this can be solved with just 'business as usual' and some technical solutions? With today's emissions levels, that remaining CO2 budget will be entirely gone within less than 8 1/2 years.

"There will not be any solutions or plans presented in line with these figures here today, because these numbers are too uncomfortable. And you are still not mature enough to tell it like it is.

"You are failing us. But the young people are starting to understand your betrayal. The eyes of all future generations are upon you. And if you choose to fail us, I say: We will never forgive you.

"We will not let you get away with this. Right here, right now is where we draw the line. The world is waking up. And change is coming, whether you like it or not.

"Thank you."

Greta Thunberg made an impassioned speech at the UN earlier this week, berating world leaders for inaction over global warming Greta Thunberg made an impassioned speech at the UN earlier this week, berating world leaders for inaction over global warming Photo: GETTY IMAGES NORTH AMERICA / STEPHANIE KEITH