16-year-old Swedish climate activist Greta Thunberg revealed that her younger sister is suffering from the "systematic bullying, hatred, and harassment" her family receives on a daily basis.

Thunberg told Swedish newspaper Dagens Nyheter that her 13-year-old sibling has "no support whatsoever" and that if people want to help her [Greta] they should support her sister because "she is a wonderful and strong person."

Thunberg also discussed how her powerful UN speech came about and how she wanted to make sure she "blamed and shamed" those in power.

The 16-year-old also said that she believes that the 2016 election of US President Donald Trump "was a turning point for climate change."

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After her powerful speech at the United Nations, things have calmed down a little for 16-year-old Swedish activist Greta Thunberg. While she's been traveling across Canada to meet politicians and join climate protests, Thunberg hasn't been doing as many interviews with journalists.

But the climate activist made an exception for Swedish newspaper Dagens Nyheter, which was one of the first papers to ever interview Thunberg back when she was striking on her own in front of the Swedish Parliament in 2018.

Among other things in the interview published Tuesday, Thunberg spoke openly about how she is coping with daily harassment, which mainly manifests itself online. Thunberg's family is more affected, she said: "The one who suffers is my sister. She is 13 years old and has to endure systematic bullying, hatred, and harassment."

Read more: Greta Thunberg responds to 'haters,' asking why adults 'spend their time mocking and threatening teenagers and children for promoting science'

"The people who write threats and hate to me do it to the whole family, even to her. The difference between me and the people who are left at home is that I am always traveling, inaccessible," she said. The family regularly reports the threats to the police.

Thunberg added that while she is constantly offered assistance by those around her, her sister has "no support whatsoever." She said: "The best way to help me at the moment is supporting my sister. Not because she is my sister, but because she is a wonderful and strong person."

Thunberg also shared more info about how her headline-grabbing UN speech in September came about. She said she had been thinking about the speech, in which she accused politicians of stealing her youth, for months now, and that she wanted to make sure that it "blamed and shamed" the people in power.

Read more: 2 striking photos taken just over a year apart show how Greta Thunberg's climate strike inspired millions

When asked if she gets help with her speeches, she replied: "When the speech is reasonably finished, I will send it to several scientists. They are always different, depending on who is an expert in a certain field. I usually get an answer within a few hours. Comments like: 'Here you should add that' or something. If the facts are wrong or misleading, I'll change it."

In the interview, Thunberg also commented on US President Donald Trump. She told the reporter that when Trump was elected in 2016 she thought it was "critical moment", but not in a negative sense. "I wanted people to wake up. I thought, if he's been elected, people will have to wake up."

The US president is a stubborn denier of climate change, but she thinks that his uncompromising attitude has been good for the movement: "The climate movement would definitely not be so strong today if Hillary Clinton would have won ... I may be wrong, but I believe that Trump's election was a turning point for climate change."

Thunberg will be joining a climate strike in Edmonton, Canada on Friday.