Shultz favors a revenue-neutral carbon tax as the most economically efficient means of mitigating anthropogenic climate change. In April 2013, he co-wrote, with economist Gary Becker, an opinion article in the Wall Street Journal that concluded that "a revenue-neutral carbon tax would benefit all Americans by eliminating the need for costly energy subsidies while promoting a level playing field for energy producers." He repeated this call in a September 2014 talk at MIT. In March 2015, Shultz wrote in The Washington Post that he recommended "level[ing] the playing field for competing sources of energy so that costs imposed on the community are borne by the sources of energy that create them, most particularly carbon dioxide", and doing so through a carbon tax that is "revenue-neutral, returning all net funds generated to the taxpayers so that no fiscal drag results and the revenue would not be available for politicians to spend on pet projects." In 2017, Shultz cofounded the Climate Leadership Council, along with Reagan Secretary of State James Baker and George W. Bush Secretary of the Treasury Henry Paulson. In 2017, this group of "Republican elder statesmen" proposed that conservatives embrace a fee and dividend form of carbon tax (in which all revenue generated by the tax is rebated to the populace in the form of lump-sum dividends), as a policy to deal with anthropogenic climate change. The group also included Martin S. Feldstein and N. Gregory Mankiw.
Shultz's grandson, Tyler Shultz, joined Theranos in September 2013 after graduating from Stanford University with a degree in biology. Tyler was forced to leave the company in 2014 after raising concerns about its testing practices with Holmes and his grandfather. George Shultz initially did not believe Tyler's warnings, pressured him to keep quiet, and continued to advocate for Holmes and Theranos. Tyler eventually contacted reporter John Carreyrou (who went on to expose the scandal in The Wall Street Journal), but as summarized by ABC Nightline, "it wasn’t long before Theranos got wind of it and attempted to use George Shultz to silence his grandson." Tyler went to his grandfather's house to discuss the allegations, but was surprised to encounter Theranos attorneys there, who pressured him to sign a document. As recounted in the documentary The Inventor: Out for Blood in Silicon Valley, they questioned Tyler in a manner that George described on April 4, 2017, as verbal assault. Tyler did not sign any agreements, even though George pressured him to: "My grandfather would say, like, things like 'your career would be ruined if [Carreyrou's] article comes out.'" Tyler and his parents spent nearly $500,000 on legal fees, selling their house to raise the funds, in fighting Theranos's accusations of violating the NDA and divulging trade secrets.