Millennials may soon inherit $24 trillion, and a PR exec says businesses should 'watch out' 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."