Companies should "watch out" for millennials when it comes to how environmental, social and governance issues influence where they invest their money, according to the head of ESG governance at PR firm Edelman.
Chuka Umunna, a former British lawmaker, told CNBC's "Squawk Box Europe" on Wednesday that around $24 trillion of wealth, in the U.S. alone, was in the process of being transferred to millennials from baby boomers and older generations.
A 2015 study by Deloitte said that nearly $24 trillion of wealth would be transferred in the U.S. over the following 15 years, while a separate 2017 UBS study predicted millennials' could be worth that amount as soon as this year.
The Pew Research Center defines millennials as those aged 24- to 39-years-old and baby boomers aged between 56- to 74-years-old. The so-called silent generation is aged between 75-92-years-old.
Umunna warned that millennials were much more "militant" on ESG issues and, subsequently, where they invested their money, including savings and pensions.
He added that this wealth transfer would only increase as "sadly, life goes on and some of the baby boomer generation pass away."
This might also explain the "explosion" of interest in ESG, he continued. "It's not necessarily all happening at the instigation of politicians here, the market is demanding change."
Umunna was the former shadow secretary of state for business in Britain's opposition Labour party, before switching parties to become a member of parliament for the Liberal Democrats. He retired from politics after losing his seat in the U.K. general election last year.
The former politician also referred to Edelman's annual "Trust Barometer" as evidence that over its nearly two decades of surveying consumer and investor sentiment, it had learned that people would "punish companies that they don't think do the right thing by all stakeholders."
Indeed, in this year's survey, conducted amid the coronavirus pandemic, nine out of 10 respondents said they wanted a company to protect the well-being and financial security of their employees and suppliers, even if that meant suffering financial losses.
Two-fifths of the 22,000 people polled across 11 markets, said they had convinced other people to stop using a brand they felt was not acting appropriately in response to the crisis.
ESG funds outperforming the wider stock market during the coronavirus-fueled sell-off has also been a signal of this change, Umunna suggested. Bank of America recently found the top 50 stocks most commonly held by the ESG-focused funds outperformed the bottom 50 stocks by 22 percentage points.
In this sense, there has been a "big difference" in how companies are coming out of the pandemic compared with the 2008 financial crisis, Umunna said, in that they have learned they "cannot just go back to business as usual."
Umunna warned that if we continued with a "dysfunctional variety of capitalism that doesn't deliver enough for people, that doesn't raise living standards, that doesn't deal with the looming climate crisis, then the entire system will lose support altogether."
— CNBC's Pippa Stevens contributed to this article.