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 carsthat 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.”