Artificial intelligence will spur economic growth and create new wealth. Machines that “think” like humans will help solve huge problems, from curing cancer to climate change. Yet millions of human workers will need to retrain, as robots make their existing jobs redundant.

These are the contrasting messages provided by the world’s leading technologists during the World Economic Forum in Davos this week, as political and business leaders ponder how best to respond to the rise of smart machines.

Sebastian Thrun, the inventor of Google’s self-driving cars and an honorary professor at Delft University of Technology, in the Netherlands, said “almost every established industry is not moving fast enough” to adapt their businesses to this change.

He suggested self-driving cars would make millions of taxi drivers redundant and planes running solely on autopilot would remove the need for thousands of human pilots.

One of the central themes of this year’s conference is the “Fourth Industrial Revolution,” referring to how technological breakthroughs are expected to transform industries across the world. Delegates argued that advances in robotics and artificial intelligence would have the transformative effect that steam power, electricity and ubiquitous computing achieved in previous centuries.

“[Artificially-intelligent machines] can look at a brainscan better than most radiologists, but they can also weld better than any human,” said Illah Nourbakhsh is a professor of robotics at Carnegie Mellon University, the institution partnering with taxi app group Uber to build driverless cars. “It’s affecting white collar and blue collar jobs. Nobody is inherently safe.”

But Prof Thrun was optimistic that redundant roles would quickly be replaced.

“With the advent of new technologies, we’ve always created new jobs,” he said. “I don’t know what these jobs will be, but I’m confident we will find them”

Not all are convinced. According to a study released by WEF this week, increased automation and artificial intelligence in the workforce will lead to the loss of 7.1m jobs over the next 5 years in 15 leading economies, while helping create just 2m new jobs over the same period.

Across industries, leading executives worried about the effect of job displacement.

Peter Brabeck-Letmathe, chairman at Nestlé, warned some countries would become unstable if businesses could not replace jobs taken by machines.

“Other industrial revolutions cost a lot of people their heads,” he said. “I’m not sure we have the time for the wonderful markets to fix all these problems.”

Satya Nadella, chief executive of Microsoft, said: “This challenge of displacement is a real one, [but] I feel the right emphasis is on skills, rather than worrying too much about the jobs [which] will be lost. We will have to spend the money to educate our people, not just children but also people mid-career so they can find new jobs.”

For workers to adapt, Prof Thrun argued that the way people approach their professional lives would require change.

The robotics pioneer is also the founder of Udacity, a Silicon Valley start-up that enrols high-earning professionals into six-month online courses, retraining them in order to switch jobs. Due to growing automation, he predicted it would become the norm for workers to change jobs every few years.

“In the United States, in 2012, figures from Department of Labour Statistics show the average tenure [in a job] was 4.6 years and it’s shrinking,” he said.

Erik Brynjolfsson, the Massachusetts Institute of Technology professor and co-author of The Second Machine Age said: “We’re moving to a world where there will be vastly more wealth and vastly less work. That shouldn’t be a bad a thing, and shame on us if we turn it into a bad thing.”