Davos (CNN) While many delegates at the World Economic Forum arrive in their private jets, 16-year-old Swedish climate activist Greta Thunberg took a 32-hour train from her home to Davos.

She's also been camping out, trading a luxury hotel stay for a tent in 0 degrees Fahrenheit.

And, in the process, she's been giving Davos a run for its money.

Greta Thunberg arrives in Davos on Wednesday by train.

On Thursday, Thunberg gave an impromptu speech at a lunch with a star-studded guest list that included music stars Bono and Will.i.am, Salesforce CEO Marc Benioff, former Goldman Sachs President Gary Cohn, and an array of bankers and investors. She roasted them.

"Some people say that the climate crisis is something that we will have created, but that is not true, because if everyone is guilty then no one is to blame. And someone is to blame," Thunberg said flatly. "Some people, some companies, some decision-makers in particular, have known exactly what priceless values they have been sacrificing to continue making unimaginable amounts of money. And I think many of you here today belong to that group of people."

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