The attempt by Newt Gingrich to cover his tracks on climate change has been one of the shabbier little episodes of the 2012 presidential campaign. His forthcoming sequel to “A Contract with the Earth” was to feature a chapter by Katharine Hayhoe, a young professor of atmospheric sciences at Texas Tech University. Hayhoe is a scientist, an evangelical Christian and a moderate voice warning of climate disruption.

Then conservative media got wind. Rush Limbaugh dismissed Hayhoe as a “climate babe.” An Iowa voter pressed Gingrich on the topic. “That’s not going to be in the book,” he responded. “We told them to kill it.” Hayhoe learned this news just as she was passing under the bus.

A theory about the role of carbon dioxide in climate patterns has joined abortion and gay marriage as a culture war controversy. Climate scientists are attacked as greenshirts and watermelons (green on the outside, red on the inside). Skeptics are derided as flat-earthers. Reputations are assaulted and the e-mails of scientists hacked.

A few years ago, the intensity of this argument would have been difficult to predict. In 2005, then-Gov. Mitt Romney joined a regional agreement to limit carbon emissions. In 2007, Gingrich publicly endorsed a cap-and-trade system for carbon.

What explains the recent, bench-clearing climate brawl? A scientific debate has been sucked into a broader national argument about the role of government. Many political liberals have seized on climate disruption as an excuse for policies they supported long before climate science became compelling — greater federal regulation and mandated lifestyle changes. Conservatives have also tended to equate climate science with liberal policies and therefore reject both.

The result is a contest of questioned motives. In the conservative view, the real liberal goal is to undermine free markets and national sovereignty (through international environmental agreements). In the liberal view, the real conservative goal is to conduct a war on science and defend fossil fuel interests. On the margin of each movement, the critique is accurate, supplying partisans with plenty of ammunition.

No cause has been more effectively sabotaged by its political advocates. Climate scientists, in my experience, are generally careful, well-intentioned and confused to be at the center of a global controversy. Investigations of hacked e-mails have revealed evidence of frustration — and perhaps of fudging but not of fraud. It is their political defenders who often discredit their work through hyperbole and arrogance. As environmental writer Michael Shellenberger points out, “The rise in the number of Americans telling pollsters that news of global warming was being exaggerated began virtually concurrently with the release of Al Gore’s movie, ‘An Inconvenient Truth.’”

The resistance of many conservatives to arguments about climate disruption is magnified by class and religion. Tea Party types are predisposed to question self-important elites. Evangelicals have long been suspicious of secular science, which has traditionally been suspicious of religious influence. Among some groups, skepticism about global warming has become a symbol of social identity — the cultural equivalent of a gun rack or an ichthus.

But however interesting this sociology may be, it has nothing to do with the science at issue. Even if all environmentalists were socialists and secularists and insufferable and partisan to the core, it would not alter the reality of the Earth’s temperature.

Since the 1950s, global temperatures have increased about nine-tenths of a degree Celsius — the recent conclusion of the Berkeley Earth Surface Temperature Project — which coincides with a large increase in greenhouse gasses produced by humans. This explanation is most consistent with the location of warming in the atmosphere. It best accounts for changing crop zones, declining species, thinning sea ice and rising sea levels. Scientists are not certain about the pace of future warming — estimates range from 2 degrees C to 5 degrees C over the next century. But warming is already proceeding faster than many plants and animals can adapt to.

These facts do not dictate a specific political response. With Japan, Canada and Russia withdrawing from the Kyoto process, the construction of a global regulatory regime for carbon emissions seems unlikely and may have never been possible. The broader use of nuclear power, the preservation of carbon-consuming rain forests and the encouragement of new energy technologies are more promising.

But any rational approach requires some distance between science and ideology. The extraction and burning of dead plant matter is not a moral good — or the proper cause for a culture war.