Two scientific studies that nearly crossed paths on the way to publication by the National Academy of Sciences raise serious questions about climate change - and the liberal knee-jerk reaction that it must be caused by human activities.
About a week ago, a study suggesting methane may be more at fault for global warming than had been thought previously surfaced. It was published in the Proceedings of the National Academy of Sciences.
As we reported, the study indicated U.S. releases of methane into the atmosphere may be as much as 50 percent higher than the federal government estimates. That is important because President Barack Obama and his Environmental Protection Agency have placed virtually all of the blame for climate change on emissions of carbon dioxide.
But methane is about 21 times more powerful than carbon dioxide in influencing global warming.
Two principal sources of methane emissions were focused on by the study's scientists. They are the natural gas and oil industries - and livestock. Yes, livestock. Cattle in particular release enormous amounts of methane through their digestive processes.
In September, another study was published in the Proceedings of the National Academy of Sciences. Presumably, NAS officials believe it, too is credible.
That study indicated drilling for natural gas does not emit as much methane as had been believed. Total leakage of gas from well sites was less than one-half of one percent of gas produced from the wells, the study concluded.
Of course, other aspects of methane emissions by the energy industry need to be studied. In view of the November report, the EPA certainly should be looking into whether carbon dioxide is being blamed disproportionately for climate change.
But the two studies, taken together, also suggest environmentalists should be thinking more objectively about whether industry, including coal-fired power plants, is being targeted unscientifically by those who worry about climate change.
If natural sources of pollution are a substantial cause of climate change, that knowledge ought to be folded into strategies to combat the problem. Refusing to do so simply is not a rational approach to what Obama insists is a genuine crisis.