Roger Pielke Sr. is a well respected climatologist and professor. His blog is a top go-to place on the Internet for those searching for the happy middle of the contentious climate-change debate. (His son, Roger Pielke, Jr., also has a must-read blog for Climategate students.)

Here at MasterResource, Chip Knappenberger covers climate science. Knappenberger is skeptical of ultra-skepticism and trenchantly challenges exaggerated science in the service of climate alarmism.

In this tradition, I recently read a very interesting post on Pielke senior’s blog, titled “Three Distinctly Different Climate Science   Perspectives,” that is worth sharing with MasterResource readers. Here is what he wrote, and my critical comment is at the end.

There needs to be recognition that there are three distinctly different viewpoints with respect to the extent that humans alter the climate system.

“The fraudulence of the Copenhagen approach – ‘goals’ for emission reductions, ‘offsets’ that render even iron-clad goals almost meaningless, an ineffectual ‘cap-and-trade’ mechanism – must be exposed. We must rebel against such politics-as-usual.”

– James Hansen, “Never-Give-Up Fighting Spirit,” November 30, 2009

There is a civil war on the Left against cap-and-trade as the centerpiece of a U.S. climate bill. Among the leading critics is NASA scientist and Al Gore mentor James Hansen, who reiterated his opposition in Sunday’s The Observer with Copenhagen’s climate summit in mind:

“Cap and trade with offsets … is astoundingly ineffective. Global emissions rose rapidly in response to Kyoto, as expected, because fossil fuels remained the cheapest energy.

Cap and trade is an inefficient compromise, paying off numerous special interests. It must be replaced with an honest approach, raising the price of carbon emissions and leaving the dirtiest fossil fuels in the ground.”

Editor Note: In our ‘best of MasterResource’ weekend series, we are pleased to reprint the September 30th post by Ken Green in light of the stalemate of U.S. climate legislation for 2009. Obviously, the onset of Climategate will only reinforce a worst-case scenario for climate alarmism politics.

Desperation is setting in among climate alarmists who by their own math can see that the window is rapidly closing on “saving the planet.”

James Hansen, for instance, said three years ago in the New York Review of Books: “We have at most ten years—not ten years to decide upon action, but ten years to alter fundamentally the trajectory of global greenhouse emissions.” That was also Al Gore’s estimate in “An Inconvenient Truth.” But the time has been ticking away, and it’s increasingly obvious that the Gore/Hansen “wrenching transformation” of the U.S.…