SAN FRANCISCO — Google will invest $1 billion over the next five years in nonprofit organizations helping people adjust to the changing nature of work, the largest philanthropic pledge to date from the Internet giant.

The announcement of the national digital skills initiative, made by Google CEO Sundar Pichai in Pittsburgh, Pa. Thursday, is a tacit acknowledgment from one of the world’s most valuable companies that it bears some responsibility for rapid advances in technology that are radically reshaping industries and eliminating jobs in the U.S. and around the world.

Pichai’s pitstop in an old industrial hub that has reinvented itself as a technology and robotics center is the first on a “Grow with Google Tour.” The tour that will crisscross the country will work with libraries and community organizations to provide career advice and training. It heads next to Indianapolis in November. 

“The nature of work is fundamentally changing. And that is shifting the link between education, training and opportunity,” Pichai said in prepared remarks at Google’s offices in Pittsburgh. “One-third of jobs in 2020 will require skills that aren’t common today. It’s a big problem.”

Google will make grants in its three core areas: education, economic opportunity and inclusion. Already in the last few months, it has handed out $100 million of the $1 billion to nonprofits, according to Pichai.

The largest single grant — $10 million, the largest Google’s ever made — is going to Goodwill, which is creating the Goodwill Digital Career Accelerator. Over the next three years Goodwill, a major player in workforce development, aims to provide 1 million people with access to digital skills and career opportunities. Pichai says 1,000 Google employees will be available for career coaching. 

In all, Google…