SAN JOSE, Calif. - During a visit to Silicon Valley, I had an interesting encounter with a salesperson of the future: a robot. And it gave me a hint of what much of the workforce may look like sooner than many people think.

The robot - a tall, white tower with cameras on its sides and a dome-shaped sensor on its top - was moving along the entrance corridor of a giant Lowe's home improvement center, and stopped in front of me when I approached it.

"Hi there. Is there something I can help you find?" it asked with a slightly feminine-sounding voice. I responded that I was looking for a light bulb, and a big tablet on the robot's chest immediately showed me about a dozen different types of bulbs, each one with a photo and price.

When I told it which one, the robot said, "That item appears to be on aisle 12. Would you like me to take you there?" I said yes, and the robot said, "Sure. Follow me." And off it went.

A new study by the McKinsey Global Institute says that robots like this one and other forms of automation will dramatically impact at least half of our jobs by as early as 2035. In Latin America and Asia, the impact of automation may be bigger, because more people work in repetitive manufacturing or agricultural jobs that can be easily replaced by robots, the study says.

Automation may affect more than 51 percent of the jobs in Mexico, Colombia and Peru; about 50 percent in China, India and Brazil; 48 percent in Argentina; and 46 percent in the United States and Canada, the study says.

The McKinsey study paints a pretty optimistic picture, saying that only 5 percent of worldwide jobs will be fully automated, and that most jobs will be only partially replaced by machines. Most people will work alongside robots that will take over the most tedious parts of their jobs, productivity will increase, and countries that embrace automation will become more prosperous, it says.

Marco Mascorro, CEO of FellowRobots, the company that created the robot sales assistant that helped me out at the Lowe's store, told me that his machine has not eliminated any jobs. The robot, which in addition to helping customers spends much of its time scanning the store's shelves to see if there are any missing items, has relieved salespeople from having to do boring inventory work, he said.

"In the past, employees had to spend hours walking up and down the aisles to find which items needed to be restocked," Mascorro said. "Now, the robot does that. And employees can spend more time doing what they enjoy the most, which is using their expertise to give advice to customers on things such as how to fix their kitchen sink."

But most economists and futurists I interviewed in Silicon Valley readily admit that the coming wave of automation will rattle the global workforce. While technology in the past has always produced more jobs than it killed, it is now advancing at such a fast pace that it may create greater unemployment, they said.

With robots starting to work at stores; super-computers taking over parts of the jobs of bankers, lawyers and accountants; and soon-to-come self-driven cars that will replace millions of truckers and taxi drivers, "the problem is that everything is happening at the same time," says Vivek Wadhwa, a Carnegie Mellon University futurist and author of the new book "The Driver in the Driverless Car."

"Yes, there will be some new jobs created, but those jobs will be a tiny fraction of the ones we will lose," Wadhwa told me.

My opinion: While economists figure out whether the next wave of the automation revolution will be good or bad for the workforce, countries should start a serious discussion about what to do with the workers who will be displaced by technology.