A year after warning world leaders “our house is on fire”, Greta Thunberg has returned to Davos to chide decision makers for their inaction on climate change.

Thunberg on Tuesday accused politicians of “giving up” on attempts to limit global warming to 1.5 degrees celcius, a target that was agreed at the Paris climate summit in 2015.

“Our house is still on fire,” Thunberg said during a keynote address at Davos. “Your inaction is fuelling the flames by the hour. We are still telling you to panic, and to act as if you loved your children above all else.”

The 17-year-old Swedish climate activist accused world leaders of “empty words and promises” and said efforts to become net carbon neutral were simply “cheating and fiddling around with numbers.”

“We are not telling you to ‘offset your emissions’ by just paying someone else to plant trees in places like Africa while at the same time forests like the Amazon are being slaughtered at an infinitely higher rate,” she said.

“Planting trees is good, of course, but it’s nowhere near enough of what needs to be done, and it cannot replace real mitigation or rewilding nature.

“From a sustainability perspective, the right, the left, as well as the center have all failed,” she said. “No political ideology or economic structure has been able to tackle the climate and environmental emergency and create a cohesive and sustainable world.”

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Thunberg called on all nations of the world to immediately stop all fossil fuel search and extraction, end fossil fuel subsidies, and divest from fossil fuels.

“Let’s be clear,” she said. “We don’t need a ‘low carbon economy.’ We don’t need to ‘lower emissions.’ Our emissions have to stop. And until we have the technologies that at scale can put our emissions to minus then we must forget about net zero — we need real zero.

“Any plan or policy of yours that doesn’t include radical emission cuts at the source starting today is completely insufficient.”

Giving up fossil fuels “will be hard,” Thunberg said, but necessary.

“The facts are clear, but they’re still too uncomfortable for you to address,” she said.

“What will you tell your children was the reason to fail and leave them facing the climate chaos you knowingly brought upon them?”

Thunberg was addressing world leaders and top business people at the World Economic Forum’s annual meeting in Davos, Switzerland. Around 3,000 of the world’s top decision makers, including over 50 heads of state, are attending the 50th edition of the conference.