"We are right now in Davos where (there are) basically the people who are mostly fueling the destruction of the planet," she said.
"The people who are at the very core of the climate crisis, the people who are investing in fossil fuels etc., and yet somehow these are the people that we seem to rely on for solving our problems."
The 20-year-old Swede spoke on the sidelines of the WEF with fellow activists Helena Gualinga of Ecuador, Vanessa Nakate of Uganda and Luisa Neubauer of Germany at a CNBC panel that included International Energy Agency head Fatih Birol.
Thunberg said change will have to come from "the bottom up".
"Without massive public pressure from the outside, these people are going to go as far as they possibly can, as long as they can get away with it," she said.
"They will continue to invest in fossil fuels. They will continue to to throw people under the bus for their own gain."
Birol said the energy sector must be transformed or "we have no chance whatsoever to reach our climate targets".
He said that attention to climate change is "sliding down" the international agenda including in Davos.
"It is now time to ring the alarm bells, bring the climate crisis together with other crises, the energy crisis, the food crisis, atop of the international policy agenda," he said.