• President Trump attends Davos for the second time.
  • Speech is upbeat on US economy and increasing energy output.
  • Says doom-mongers have always been wrong in the past.

The world should not heed the "perennial prophets of doom", US President Donald Trump told the World Economic Forum's Annual Meeting where climate change is one of the main themes.

In a speech just minutes before teenage activist Greta Thunberg addressed a session called Averting a Climate Apocalypse, Trump warned there were forces at work that aimed to "destroy our economy and wreck our country or eradicate our liberty".

"This is not a time for pessimism. This is a time for optimism. To embrace the possibilities of tomorrow, we must reject the perennial profits of doom and their predictions of the apocalypse. They are the heirs of yesterday's foolish fortune tellers," he said.

"They want to see us do badly, but we don't let that happen. They predicted an overpopulation crisis in the 1960s, mass starvation in the 70s, and an end of oil in the 1990s. These alarmists always demand the same thing: absolute power to dominate, transform and control every aspect of our lives. We will never let radical socialists destroy our economy, wreck our country or eradicate our liberty."

Fully tapped American energy

Trump was speaking shortly after a session at which Thunberg quoted the UN climate science panel, the IPCC, which says that we need to dramatically reduce carbon dioxide emissions this decade to ensure global temperature rise is limited to 1.5 degrees Celsius - going beyond that could trigger disastrous 'tipping point' consequences.

"These numbers aren't anyone's opinions or political views. This is the current best available science," Thunberg said.

While most major economies around the world are aiming to curb emissions under the terms of the Paris Agreement, Trump said increases in fossil fuel production in the US had helped fuel unprecedented American affluence.

Total primary energy supply (TPES) by source, United States 1990-2018
US energy production
Image: IEA

"I knew that if we unleashed the potential of our people, cut taxes, slashed regulation … fixed broken trade deals and fully tapped American energy, the prosperity would come thundering back at a record speed. And that is exactly what we did and that is exactly what happened."

Rather than accept more regulation tying the hands of business, Trump said free enterprise was the path to improving the state of the world.

Workers first

"We continue to embrace technology not to shun it. When people are free to innovate, millions will live longer, happier and healthier lives. For three years now, America has shown the world that the path to a prosperous future begins with putting workers first, choosing growth and freeing entrepreneurs to bring their dreams to life."

And he said people should put their faith in technology to solve the big problems.

The dome of the Basilica di Santa Maria del Fiore is seen from Giotto's bell tower in Florence July 16, 2012. The cathedral complex, located in Pizza del Duomo, includes the bell tower and a Baptistery - all three buildings are part of the UNESCO World Heritage Site. REUTERS/Clarissa Cavalheiro (ITALY - Tags: TRAVEL RELIGION TPX IMAGES OF THE DAY) - GM1E8CE1S0N01
Renaissance man: Trump cited Florence cathedral as a triumph of human ingenuity
Image: REUTERS/Clarissa Cavalheiro

Speaking in the heart of Europe, Trump cited the example of Florence cathedral, whose magnificent dome was built in the 15th century despite naysayers who doubted it could be done.

"The technology did not yet exist, to complete their design, city fathers forged ahead anyway, certain they would figure it out someday," Trump said