"We believe they are 'good enough,' particularly for broad universe index funds," Blake said via e-mail. The case of Tesla, shows how ratings can reflect differences in approach rather than any flaws in analysis or data. In its report, Sustainalytics acknowledged CEO Elon Musk 's goal of making Tesla's "Gigafactory" built in Nevada entirely powered by renewable energy. Yet it still gave the company an overall score of 55 out of 100 for not disclosing data on the carbon emissions from its automaking operations. "Their lack of corporate sustainability reporting is kind of a shame, especially considering their main product is a low-carbon product," Sustainalytics' MacMahon said. Similarly, MSCI rated Tesla 5.3 on a 10-point scale for "carbon emissions," including its own operations.