(Bloomberg) — Greta Thunberg brought a stark message to the business elite gathering in Davos: Everybody is talking about climate change, but nobody is doing anything.

Her appearance at the opening of the World Economic Forum was a striking sign that the debate about how to stop the Earth warming has become mainstream in business circles. Yet only a handful of executives from the oil, gas and coal industries that are chiefly responsible for warming the planet were seen attending the panel at which Thunberg spoke on Tuesday.

Meanwhile, U.S. President Donald Trump used his speech at the event to tout the benefits of soaring American oil and gas production and make a thinly veiled attack on those who warn about looming environmental catastrophe.

“The climate and environment is a hot topic right now, thanks to young people pushing,” 17-year-old Thunberg said at the Swiss ski resort, where about 3,000 business and political leaders gather each year. “Pretty much nothing has been done, since the global emissions of CO2 have not reduced.”

The Swedish activist’s words came as the World Economic Forum sounds alarm bells on climate change. This year and for the first time on record, environmental risks occupy the group’s top five long-term concerns, while corporate executives say they’re increasingly concerned about environmental issues. But young activists at Davos said none of this is enough.

Thunberg is giving relevance to the Davos gathering, which for years has suffered from criticism that it was largely a billionaires’ playground where the rich debated among themselves without hearing outside voices. On Tuesday, there was a full room at this first 8:30 a.m. panel featuring young activists — something relatively unusual for a climate change event at Davos.

Enterprise Threats

The debate on climate change is forcing businesses to respond to demands to stop carbon dioxide and other greenhouse gas emissions. While some have been slow in embracing the fight, executives at Davos highlighted that the overall views from within the business community have dramatically changed over the last decade or so, moving from denial and questioning science into complete acceptance.

“I have come to Davos for well over a decade and I see behind the scenes, among top executives, a huge change in perception of the risk of climate change,” said Marco Dunand, the head of Mercuria Energy Trading SA, one of the worlds’ largest oil traders. “It’s not just talk: it’s translating into billions of dollars in investments in the energy transition.”

Activists’ language has made its way to boardrooms across the world too. At another morning panel at Davos, Iberdrola SA Chief Executive Officer Ignacio Galan called on companies to close coal-powered plants in order to curb emissions.

“We are in a hurry, we have to move fast,” he said. “There is already money available, cheap money, cheap technology, competitive technology and political decision in many countries to do so. Let’s not continue delaying and postponing”

Trump Encounter

Trump landed at Davos on Tuesday morning and was welcomed by the words “Act on climate,” carved into the snow on a hill near the helicopter landing zone. He didn’t mention the topic in his speech at the forum later in the day, focusing instead on America’s growing economy and record oil and gas production.

“This is not a time for pessimism, this is a time for optimism,” Trump said as Thunberg watched from the audience. “We must reject the perennial prophets of doom and their predictions of the apocalypse. They are the heirs of yesterday’s foolish fortune tellers.”

The President and the activist’s first and only meeting last year became instantly viral as Thunberg was filmed furiously staring at Trump. While they’ve never spoken face to face, they both seem to follow each other closely on Twitter.

“Greta must work on her anger management problem, then go to a good old fashioned movie with a friend! Chill Greta, Chill!”, Trump tweeted in December shortly after the activist was named person of the year by Time magazine. Thunberg didn’t directly answer, but changed her Twitter biography to “A teenager working on her anger management problem.”

Three-day March

Hundreds of climate activists are due to arrive at Davos on foot on Tuesday following a three-day march across the Swiss Alps. Protesters will gather at the ski resort and stage a demonstration calling for the end of the World Economic Forum. Companies attending Davos for the past five decades bear a great responsibility for today’s climate crisis, activists say.

“We are tired of empty promises. But we have hopes,” said Puerto Rican activist Salvador Gomez-Colon. “We’re not waiting years to see the change that we want to see.”

Thunberg urged businesses, governments and the media to listen to scientists. She cited research by the Intergovernmental Panel on Climate Change from 2018 that concluded that the carbon budget– the amount that can be released while still keeping global warming limited to a specific level — stands at 340 gigatons of carbon dioxide and that, at current emission levels it will be gone in less than eight years.

“Since last summer I have been repeating these numbers over and over again in every speech,” she said. “I know you don’t want to talk about this. I assure you I will continue to repeat these numbers until you do.“

–With assistance from Jeremy Hodges.