Climate activist Greta Thunberg has found a free, carbon neutral ride back across the Atlantic, leaving U.S. shores on Wednesday with some stinging words for President Donald Trump.

The 16-year-old has spent the past 11 weeks criss-crossing America, delivering excoriating messages everywhere about the state of the planet, after she sailed from her home in Sweden rather than fly.

She spoke at the United Nations, spent time with former U.S. President Barack Obama, received the keys to the city of Montreal and drove a Tesla electric car lent to her by actor and ex-governor of California Arnold Schwarzenegger.

Along the way Tesla CEO Elon Musk praised Thunberg for having “better reasoning & more heart than the vast majority of political leaders.”

On Wednesday she sailed off as a guest aboard the catamaran La Vagabonde with plans to attend the COP25 climate summit in Madrid, which starts in just under three weeks, before heading home to Sweden.

The COP25 climate meeting was due to be held in Chile but was moved to Spain at the last-minute after the South American nation was hit by protests.

So happy to say I’ll hopefully make it to COP25 in Madrid.

I’ve been offered a ride from Virginia on the 48ft catamaran La Vagabonde. Australians @Sailing_LaVaga ,Elayna Carausu & @_NikkiHenderson from England will take me across the Atlantic.

We sail for Europe tomorrow morning! pic.twitter.com/qJcgREe332 — Greta Thunberg (@GretaThunberg) November 12, 2019

She didn’t go however without a free character assessment of Donald Trump.

“He’s so extreme and he says so extreme things, so I think people wake up by that in a way,” she told AFP.

She did not address a video clip of her appearing to glower at Trump at the U.N. that went viral on social media, saying she was simply surprised to see him.

“I wondered why he was there because the thing was that he was not supposed to be there,” she explained. “That was the news. So something must have changed his mind so that he showed up there.”

Trump is not the only critic she has taken time to confront.

Last month she threatened to quit Facebook if the social media platform refuses to silence her critics.

“I am, like many others, questioning whether I should keep using Facebook or not,” Thunberg wrote in a Facebook post. “Allowing hate speech, the lack of fact-checking and, of course, the issues of interfering with democracy… are among many, many other things that are very upsetting.”

“The constant lies and conspiracy theories about me and countless others, of course, result in hate, death threats and ultimately violence. This could easily be stopped if Facebook wanted to. I find the lack of taking responsibility very disturbing,” she added.

AFP contributed to this report