This editorial appeared in the St. Louis Post-Dispatch.

Corporate shareholders are using their voting power to influence greater transparency by companies about the financial consequences of climate change. Big investors could turn out to be the environmental movement’s best friends in pressuring major corporations to address climate concerns.

A surprise vote last week by 62.3 percent of ExxonMobil shareholders highlights the power big money has over corporate behavior. Investors voted to instruct the petroleum giant to be more transparent about the cost of global measures designed to keep climate change to 2 degrees Celsius. The shareholder rebellion occurred at the company’s annual meeting in Dallas. A year earlier, a similar proposal got only 38 percent support.

Top institutional shareholders could be behind this shift toward greater corporate environmental accountability. Their support came despite a company campaign that included calling, writing and lobbying shareholders in person to vote against climate-related proposals.

Institutional asset managers typically don’t challenge management on social or political issues, but they can and should. Major asset management firms oversee trillions of investment dollars that can be used to reflect growing concerns among shareholders about important issues.

Besides, examined from a purely financial-benefit perspective, rising sea levels and global temperatures could hinder companies like ExxonMobil from operating in certain environments, which would translate into reduced financial performance and lower share values.

New York Times columnist Gretchen Morgenson wrote recently that giant asset management firms BlackRock and Vanguard, which control a combined $9 trillion in assets, each voted in favor of management-sponsored proposals about 95 percent of the time. The days of automatically yielding to management could be ending.

Rubber-stamping sends a signal that corporations are operating perfectly and don’t need to change, which Morgenson noted is an assessment clients would not agree with in some cases. She said they probably would support more transparent operations and better shareholder service overall.

Similar resolutions on climate change accountability won majority votes at Occidental Petroleum and Pennsylvania utility PPL, and hefty support at other companies, according to St. Louis Post-Dispatch business columnist David Nicklaus.

Corporations have responded to investor pressure in the past, such as during the boycott movement to end apartheid in South Africa. This is a welcome wake-up call for executives to make climate change a priority concern.