According to a recent study published in the scientific journal, Climatic Change, and reported on by The Guardian, 90 companies have been responsible for nearly two-thirds of all carbon dioxide and methane gas emissions in the entire world since 1750.

As a long-term investor, should you be concerned if your investment appears on this list? Well, if you own shares in BP (NYSE:BP), ConocoPhillips (NYSE:COP), Royal Dutch Shell (NYSE:RDS-B), Peabody Energy (NYSE:BTU), or Total SA (NYSE:TOT), it's time to ask yourself that very question. 

In the video below, Motley Fool contributor Jay Jenkins digs into the numbers for these five companies, and highlights the huge risk for both the environment and for shareholders.