The other level of disagreement exists between those who believe global warming is happening and is urgent and those who believe it is not a long term trend or who believe any climate change does not require urgent action.

At this second level mediators who are convinced that global warming is here and is urgent, will have difficulty understanding those who do not and maintaining a necessary neutrality.

Can the differences between skeptics and believers be constructively mediated? Definitely yes. Common ground exists. As with most mediation, the path to that common ground requires trust. That trust will not be won by a mediator who says mediation is necessary because the planet is dying. You cannot mediate between an atheist and a believer by saying, "I'm glad your here because God is waiting for a solution."

That mediator should limit himself or herself to mediating differences between believers.

As to the substance of your comment, Wallace, I do believe that a mediator with a particular set of beliefs (we ALL have them) is capable of assisting parties with beliefs that differ from the mediator's locate common ground. Co-mediation is often a good solution to the "differing beliefs" problem, i.e., one mediator who "believes" in global warming and our contribution to it and another who does not "believe" either in global warming or in the human contribution to it.

Additionally, whatever everyone's "beliefs" are about the cause of the present climate crisis, or its probable duration, peoples, states, and nations are dealing with what the climate crisis people believe are adverse effects on food supplies, animal life and the availability of clean drinking water.

Even if one group believed that men from Mars were responsible for these problems, or that a natural climate adjustment is likely regardless of human intervention in, say the next five years, everyone could likely agree that the current problems, whatever their source or duration, must be addressed in some way.

Mediators can help parties shift the dialogue from "who/what's at fault" to "what should we do regardless of cause." I understand that public/private agencies have tackled issues such as separation of church and state and abortion, about which the parties involved in seeking common ground have radically different beliefs, with a pretty high degree of success.

If we were so cautious with one another that we only mediated between "believers" of one set of beliefs or another we'd be missing the real challenges of the 21st Century.