You just can't win when it comes to that permanently imminent threat of cataclysmic global warming. A group of scientists has produced yet another alarming report that appears to throw a wrench into plans to save the planet: NOT polluting may make the soon-to-be-sweltering climate even more sweltering. Well, sort of.

The new study is featured by Scientific American, which informs us that "cleaning up air pollution may strengthen global warming." While that might sound like it directly contradicts current climate change premises, the study's authors maintain that some air pollutants, particularly aerosol emissions, are actually helping to keep the temperatures down by as much as 1.1 degree Celsius.

"That means efforts worldwide to clean up the air may cause an increase in warming, as well as other climate effects, as this pollution disappears," Scientific American concludes. If the pollutants really are masking the real warming by the 0.5 to 1.1 degree Celsius the study estimates, then the planet is already in "dangerous territory."

The report notes that the production of aerosols is linked to many activities that produce C02 emissions; however, there's not a one-to-one correspondence between the two.

The study, published in the Geophysical Research Letters journal, notes that the countries that will be most negatively impacted will be places that currently produce high levels of air pollutants, like East Asia.

While the new study presents a grim picture of future global warming, another recent climate change study tamped down some of the worst-case scenarios presented by the U.N. So at least we've got that working for us, theoretically . . .

A new study by a team of climatologists "all but rules out" the worst-case "doomsday" U.N. climate change scenarios, significantly narrowing the range of the possible temperature increases, while also eliminating the low-end predictions. The study's findings, said one leading expert, are "reassuring," though scientists still warn that potentially "significant" changes are coming.

"Our study all but rules out very low and very high climate sensitivities," University of Exeter's Peter Cox, the study's lead author, said.

The U.N.'s worst-case predictions of an increase of 4.5 degrees Celsius by 2100 are almost certainly too high, Cox and his colleagues found. Rather than the widely variable range of 1.5 - 4.5 ºC (2.7 - 8.1 ºF) promoted by the U.N.'s Intergovernmental Panel on Climate Change (IPCC), the new study predicts much narrower change ranges of 2.2 - 3.4 ºC (4 - 6.1 ºF). The study's best estimate is that global temperatures will change by 2.8 ºC (5 ºF) by 2100.

But remember, the science is settled.