I think my concern would only be if he believes using that info could give him an edge. There are plenty of people, including many professional investment advis

I think my concern would only be if he believes using that info could give him an edge. There are plenty of people, including many professional investment advisers, who believe that the obvious use of public info can give you the ability to outperform. If he's just explaining the relationship between economic output and pollution it's all good.