Many popular companies dominating the ESG investing space are taking advantage of the U.S. government and investors, according to Carson Block, founder of Muddy Waters Research. “I would like to save the world,” the famed short-seller said during an interview with “Squawk Box” outside CNBC’s Delivering Alpha conference on Wednesday. “I believe that we do have problems. However, these companies that I’ve seen, are not the ones who are going to save us. Many of these are just money grabs, dressed up — clad in green.” ESG, or environmental, social and governance investing, incorporates a slew of non-financial factors potential shareholders utilize when looking to invest in companies. It’s risen in popularity amid a drive toward green investing with companies like BlackRock hopping on the trend while also drawing its fair share of criticism. Block said a slew of companies he’s shorted — including XL Fleet , Danimer Scientific and solar stock Sunrun — are “grifting in their own way” and misleading investors. “When you get into the solar space — like Sunrun — I mean, they’re grifting the U.S. government by inflating the basis for their tax subsidy, so they’re screwing the U.S. government, they’re screwing investors by basically creating this illusion of a lot of value at the end of the rainbow,” he said. Block also called out companies he said attempt to offset wrongdoing in one area of their business and believes more money should be funneled into nuclear energy, especially given the ongoing energy crisis in Europe. “There’s so much froth in that space that still needs to unwind,” Block said.