“Since 1997, the year of the Kyoto climate protocol, the number of climate laws and policies in the world has basically doubled every five years. There were more than 1,200 by early 2017,” Mr. Hsu said. Those rules present legal-liability risk and the possibility of higher costs for companies, he said. The Kyoto Protocol is an international agreement to limit greenhouse-gas emissions.

In stewarding the Hartford fund, Mr. Hsu can draw on insights from a research partnership that Wellington created last year with the Woods Hole Research Center, a nonprofit climate specialist in Falmouth, Mass. The two are merging market know-how and climate science to identify metrics that matter for investing. Wellington, which manages funds for other companies, including Vanguard, says the partnership’s findings will inform all the portfolios it runs, not just the Hartford fund.

Jon F. Hale, global head of sustainability research for Morningstar, said he wasn’t aware of another pairing like that between Wellington and Woods Hole — plenty of money managers have begun to talk about climate change, but none have so publicly allied themselves with an independent scientific expert. Mr. Hale predicted that other big investment companies would find themselves at a disadvantage if they didn’t seek comparable means of assessing the investment implications of a warmer world.

“They have to figure out the extent to which climate change poses a direct and immediate risk to their portfolios,” he said.

An early line of inquiry in the Wellington-Woods Hole partnership is how higher temperatures may induce population migration, said Philip B. Duffy, Woods Hole’s president and executive director. “Of all of the different hazards, drought seems to be one that’s particularly powerful in inducing migration,” he said. “If there’s not water, you can’t live somewhere.”

The financial implications of that could play out in surprising ways, said Christopher J. Goolgasian, Wellington’s director of climate research. Movable assets might become more valuable than stationary ones. “You might think about cruise ships over theme parks and farm equipment over farms,” he said.