John Vechey of PopCap Games recently joined The Motley Fool for a climate change summit. His first panel guests are Dr. Rachel Cleetus and Dr. Joe Casola. Dr. Cleetus is a climate economist with the Union of Concerned Scientists, where she advocates for effective global warming policies at the state, regional, federal, and international levels. Dr. Casola is program director for science and impacts at the Center for Climate and Energy Solutions, which works to assess the current state of knowledge regarding climate change and its impacts, and to promote actions that strengthen climate resilience.

Carbon dioxide levels have skyrocketed in the last 50 years, and scientists agree that humans are the cause. Dr. Cleetus reveals what may come as a surprise: Many economists actually agree on how we should respond.

This issue is of critical importance to companies, particularly those with extremely carbon-intensive operations. In the wake of declining domestic coal consumption, Arch Coal (NYSE:ACI) and Peabody Energy (NYSE:BTU) have been looking for new markets for their carbon-heavy product. If exporting U.S. coal to overseas markets proceeds according to plan, the move will constitute one of the most significant global contributions to atmospheric carbon concentrations. Consider the effects on these companies if some of the proposals in this video become a reality.

Sara Murphy has no position in any stocks mentioned. Follow her on Twitter @SMurphSmiles. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.