With the ink barely dry on a landmark climate accord, nations now face an even more daunting challenge: how to get their industries to go along.

If nothing else, analysts and experts say, the accord is a signal to businesses and investors that the era of carbon reduction has arrived.

It will spur banks and investment funds to shift their loan and stock portfolios from coal and oil to the growing industries of renewable energy like wind and solar. Utilities themselves will have to reduce their reliance on coal and more aggressively adopt renewable sources of energy. Energy and technology companies will be pushed to make breakthroughs to make better and cheaper batteries that can store energy for use when it is needed. And automakers will have to develop electric cars that win broader acceptance in the marketplace.

“It’s very hard to go backward from something like this,” said Nancy Pfund, managing partner of DBL Partners, a venture capital firm that focuses on social, environmental and economic development. “People are boarding this train, and it’s time to hop on if you want to have a thriving, 21st-century economy.”