This past weekend Politico published a feature that asked who would be the Republican that would break the ice and turn the tide in the debate over what to do about global warming. The article not only took the view of those who argue that climate change is an imminent threat to the planet as unassailable. It also took the view that it was not unreasonable for environmental groups to assume that sooner or later some conservative Republican would flip on the issue. That would do for warming what Ohio Senator Rob Portman did for the gay marriage debate: provide a mainstream right-wing figure that would be the symbol of a national sea change that would forever marginalize opponents.

While Politico pointed out the differences between the two topics and the stiff resistance on the right to the climateers, the piece was still rooted in a belief that “denial” of global warming would probably soon be consigned to the dustbin of history by undeniable proof. Indeed, the expectation was that some forms of that proof—like a rise in the number of destructive hurricanes or other storms—would inevitably cause some in the GOP to change their minds because of the impacts on their states. But the idea that the likes of Marco Rubio will be forced to change his tune on cap and trade and other measures after much of Florida is underwater may not be as certain as liberals think. As the Wall Street Journal reported the same day the Politico piece appeared, the Intergovernmental Panel on Climate Change’s “fifth assessment report” due out later this month may go a long away toward dampening the alarmism that environmentalists are counting on to sway Congress to adopt their agenda.

Lest one think this is the product of some right-wing Koch-brother funded “denier” group, the IPCC is one of the organs of global warming orthodoxy and shared the Nobel Peace Prize with Al Gore. But once it states that the “temperature rise we can expect as a result of man-made emissions of carbon dioxide is lower than the IPCC thought in 2007,” then that will be a powerful argument to put the brakes on the alarmism the warmers are promoting. The data doesn’t debunk the notion that temperatures have risen and, as Byron York wrote in the Washington Examiner yesterday, you can bet that a group that is so deeply invested in the thesis of global warming will find a way to spin their figures as somehow reinforcing the movement’s almost religious belief in their thesis.

But if even the IPCC concedes that warming is not quite the threat they were claiming only a few years ago, it makes it much harder to argue that the amount of warming we are getting presents anything like the threat that we’ve been told to expect. Nor is it clear that the impact of all these changes will be negative.

Exaggeration of the threat from any climate change is business as usual for environmentalists who think they should be allowed to tell what they consider to be white lies in order to jolt the public and politicians into action. If the data from the IPCC and other reports are coming up short of the dire predictions of some of the computer models that have been used to back up climate alarmism, it is no surprise since it is clear that they have been designed to produce such results and interpreted accordingly.

It’s also important to note that one of the most common assumptions thrown about by the warming community—including liberals like President Obama—is that “extreme weather” is the result of climate change. That allows environmentalists to assert that virtually anything that happens out of the ordinary—whether heat waves or cold fronts, droughts or hurricanes—is the product of global warming. But as author and researcher Bjorn Lomborg points out in the Washington Post this assumption is not backed up by the sort of scientific consensus that the warmers assert is behind their alarmist models of future temperatures.

Lomborg is no climate change denier. He thinks warming is real and that it is at least partly the result of human activity. But he notes that the IPCC’s 2011 report on extreme weather provided little comfort for those who would like to blame Hurricane Sandy on climate change. The evidence shows that while some kinds of weather are getting more extreme, other activity, such as drought, is actually less likely. Nor is there any data to back up the idea that hurricanes have become stronger or more frequent. He also says other reports, including one in Nature, point to extreme weather becoming less likely as temperatures go up slightly. Nor is it a given that all of the effects of warming will be bad. This makes sense since, after all, the warming of the globe in the period after the little Ice Age of the Middle Ages in the Northern Hemisphere is widely believed to have helped fuel progress and growth in the period that gave birth to the Renaissance, the Enlightenment, and the Industrial Revolution.

As York rightly concludes, even if scientists—that group that Obama and liberals keep telling us are virtually unanimous in backing the most extreme alarmist scenarios—will debate the latest inconclusive data, it’s clear that the case for radical anti-warming measures that would impact the economy has gotten less persuasive.

Given the way belief in warming—irrespective of the lack of conclusive proof—has become embedded in popular culture as a sacred doctrine that can only be questioned at the cost of one’s status as an enlightened individual, don’t expect these new chinks in the environmentalist armor to be widely discussed in the mainstream liberal media. But left-wing groups expecting opposition to environmental alarmism to collapse shouldn’t hold their breath waiting for conservatives to abandon positions that just got stronger.