I don't really agree or even understand that there is a political consensus in the first place. (It's hard to undermine something which doesn't exist). Unfortunately, there is definitely a case to be made here for the last two sentences above.
Climate politics is collapsing because of political realities, and not real or perceived changes in how people see the science. As I have often argued, in the ongoing battle between climate scientists and skeptics there will be disproportionate carnage, because the climate scientists have so much more to lose, and not just as individuals, but also for the broader field, which includes many people simply on the sidelines.
The collapse of the political consensus surrounding climate could well be an opportunity to recast decarbonization of the global economy and adaptation to climate impacts in a manner that is much more consistent with progress toward policy goals. If climate science can be saved from itself, that would be a bonus. However, for climate science I fully expect things to get worse before they get better, simply because the most vocal, politically active climate scientists have shown no skill at operating in the political arena. The skeptics could not wish for a more convenient set of opponents.
As I have tried to argue, there are reasons that the deck is stacked that way. Pielke doesn't address those here.
Also, the fact that most of the vocal, politically active climate scientists are politically inept in no way implies that they are incorrect.
That said, it is reasonable to make a case that we haven't been effective in making such a case to the body politic in America, or elsewhere for that matter.
I'm not sure there ever was a "political consensus surrounding climate" to collapse, though as Roger alleges. He will have to make quite a case for that. Regardless, it's easy to agree that the political process is certainly doing climate science itself no good, and that climate science isn't affecting the policy arena skillfully. I certainly would like to understand why this would be so.