Greta Thunberg, the 16-year-old Swedish climate activist who spoke so passionately before the United Nations last week, is the target of a flood of online abuse and scores of misinformation and conspiracy theories. Climate change deniers seek to discredit her, climate science in general and those who speak about it.

For the record, she is not: mentally ill, a supporter of the Islamic State terrorist group or financier George Soros’ granddaughter. Her father does not live in Germany with a boyfriend and her mother is not a Satanic lesbian who teaches teenagers about abortion.

Also, there's a 99.9999% chance that humans are the cause of global warming.

What Thunberg is, is a teenager who launched a global movement of young people fighting to make adults take climate change seriously. It began in August 2018 when she started standing — alone — in front of the Swedish parliament building in Stockholm on Fridays with a sign reading “School Strike For Climate.”

Two weeks ago that lone protest became a global roar when as many as 4 million people, many of them teenagers, staged a climate strike in cities around the world.

The next day, Thunberg spoke before the U.N. Climate Action Summit in New York City. In a voice full of anger and sadness, she told world leaders, “For more than 30 years, the science has been crystal clear. How dare you continue to look away?”

Online hate targets Greta Thunberg

The attacks against her have mostly avoided facts about climate science and instead gone after Thunberg, her family and her motives. They include doctored photos, threats of violence and conspiracy theories and attacks that range from the kooky to the absurd to the scary.

The day after USA TODAY wrote about her speech at the U.N., for example, a reporter received emails suggesting Thunberg should have been aborted.

One conspiracy theory being floated online is that Thunberg is a fictional character being played by an Australian child actress named Estella Renee. This was debunked by fact-checking site Snopes.

A far-right Swedish politician said Thunberg is a "puppet in the hands of a PR company."

Another accusation is that her father doesn't live with the family and moved to Germany with his boyfriend. Actually, her father, Svante Thunberg, is an actor who lives in Stockholm with Greta’s mother, Malena Ernman, together with Greta and her sister, Beata.

Postings on Facebook in Brazil have also alleged that Greta’s mother is a Satanist lesbian who teaches abortion classes for teenagers. Ernman is in fact a mezzo-soprano opera singer who also sings popular songs and has acted in several Swedish movies and television series. In 2009, she sang in the Eurovision Song Contest representing Sweden.

There are also numerous faked photos online showing Greta posing with a member of the Islamic State and in another, with financier George Soros, who is Jewish and a frequent online target of conspiracy theories and anti-Semitic attacks. The images also have been debunked by Snopes.

Personal attacks on Greta

Multiple attacks go after Thunberg personally.

One Fox News guest called her “mentally ill.” Thunberg has been open about her diagnosis with Asperger’s syndrome, a developmental disorder on the autism spectrum that can cause people to be less comfortable with social interactions. The Fox News guest later apologized.

Conservative commentator Dinesh D’Souza compared Thunberg to Nazi propaganda, saying “Nordic white girls with braids and red checks” were often used in German publicity in the 1930s and 40s.

Last week on the popular Swedish Norwegian talk show Skavlan, Thunberg shrugged the haters off.

"It's of course annoying that people spend their time doing things like this when they could be doing something useful instead," she said. "But there will always be people who find something to complain about."

Other climate activists targeted by trolls

Given the misogynistic aims of many internet trolls, Thunberg may be a perfect target, said Brittan Heller, technology and human rights fellow at the Carr Center for Human Rights at the Harvard Kennedy School of Government at Harvard University in Massachusetts.

“If you are female or from a diverse background, you are much more likely to be targeted online," she said.

Other young activists who speak out on climate change are also been targeted by online trolls. Young women especially are harassed, spammed with pornography, and are even sent death threats, BuzzFeed News reported.

When it comes to highly-politicized issues such as climate change, online harassment becomes a weapon. Techniques include coordinated attacks, using autonomous programs to mimic real people to falsely amplify their messages, to create a false sense of grassroots consensus.

“These techniques demonstrate how a small group of people can attempt to counter a point of view and try to make themselves seem more powerful than they truly are,” said Heller, who is also a lawyer with the Washingon D.C. firm of Foley Hoag.

At the same time, the number of Americans who are either "concerned" or "alarmed" over global warming continues to increase. A survey conducted by Yale University in Connecticut in December found that 59% of Americans were worried about climate change. In 2013, that figure was 43%.

“It’s a tiny but vocal fraction of this already small minority that plays a disproportionate role in public discussions, though, including in making personal attacks or trolling,” said Kimberly Nicholas, a professor of sustainability science at the Centre for Sustainability Studies at Lund University in Sweden.

Climate scientists say such organized attacks are par for the course for anyone who dares to discuss the science. They often are highly coordinated, using the same talking points, themes and language, said Michael Mann, a veteran climatology researcher at Pennsylvania State.

After 20 years, he says he's battle-hardened. He's been deluged with emails calling him a fraud, had his university targeted in ads for allowing him to speak on his own campus and had climate change deniers suggest he be imprisoned.

But while the war of words against him and other climate scientists are reprehensible enough, attacks on those who will have to live with the consequences of climate change are worse.

“When they go after a sixteen-year-old girl like Greta—or other children—they expose themselves for the pond scum they truly are,” he said.