Chip Knappenberger and Pat Michaels write:
The United Nations Intergovernmental Panel on Climate Change (IPCC) is in the midst of finishing its Fifth Assessment Report (AR5) on the topic. Based on a series of content leaks, it seems as if the AR5 has so much internal inconsistency that releasing it in its current form will be a major fiasco.
The central issue of climate change science is the earth’s equilibrium climate sensitivity (ECS)—that is, how much the earth’s average surface temperature will increase as a result of a doubling the atmospheric carbon dioxide concentration. New and mutually consistent re-assessments of this important parameter are appearing in the scientific literature faster than the slow and arduous IPCC assessment process can digest them (presuming it even wants to—given that they are making the current AR5 look pretty bad).
Further, even if the IPCC is able to do an adequate job of assimilating this evolving and quite convincing science, the vast majority of the rest of the IPCC’s report will also have to be changed as it is highly dependent on the magnitude of the climate sensitivity.