Himalayan glaciers are melting — but not nearly as fast as the fanciful notion of global warming will have you believe.

A new study in the Aug. 2 issue of the British science journal Nature found that the solid particles suspended in the atmosphere (called “aerosols”) that make up “brown clouds” may actually contribute to warmer temperatures — precisely the opposite effect heretofore claimed by global warming alarmists.

“These findings might seem to contradict the general notion of aerosol particles as cooling agents in the global climate system …,” concluded the Nature news article summing up the study.

Based on data collected by unmanned aerial vehicles over the Indian Ocean, researchers from the University of California, San Diego and NASA reported not only that aerosols warmed temperatures, but they also increased atmospheric heating by 50 percent. This warming, they say, may be sufficient to account for the retreat of the Himalayan glaciers.

Putting aside the fact that the Himalayan glaciers have been retreating since 1780 — some 70 years before the onset of the current post-Little Ice Age warming trend and 100 years before the onset of significant global industrialization — full appreciation of the significance of the researchers’ finding requires a brief trip down recent-memory lane, one, incidentally, that no media outlet reporting this finding bothered to make.

Global warming alarmism is rooted in the idea that ever-increasing manmade emissions of greenhouse gases, primarily carbon dioxide, cause global temperatures to warm. This idea, however, doesn’t match up very well against real-world observations.

During the 20th century, for example, while manmade carbon dioxide emissions steadily increased from about 1940 to 1975, global temperatures cooled.

Global warming alarmists, such as the UN’s Intergovernmental Panel on Climate Change (IPCC), try to counter this observation by claiming that aerosol particles in the atmosphere — like soot and sulfates from fossil fuel combustion, and dust from volcanic eruptions — can mask the warming effect of greenhouse gases and cool the planet by reflecting solar radiation back into space.

So then, which is it? Do aerosols cool or warm the planet? Can they do both?

The correct answers to these questions are not as important as the fact that they are unanswered and will likely remain so for some time to come.

At the very moment that Congress considers enacting energy-price-raising and economy-killing legislation to regulate greenhouse gases based on the idea that human activity is harming global climate, the new aerosol study underscores (again) how little we understand whether and how human activities actually impact global climate.

Consider other recent research that ought to give our arm-chair climatologists in Congress pause.

In May, researchers reported in the Proceedings of the National Academy of Sciences that the rate of manmade carbon dioxide emissions was three times greater during 2000 to 2004 than during the 1990s. But while humans may be burning more fossil fuels than ever before, that ever-increasing activity isn’t having any sort of discernible or proportionate impact on global temperatures.

In April, researchers from the Lawrence Livermore National Laboratory reported in the Proceedings of the National Academy of Sciences that forests in northern regions — those north of the line of latitude that runs through southern Cuba — will warm surface temperatures by an estimated 10 degrees Fahrenheit by the year 2100.

Last October, Swedish researchers reported that cosmic-ray-caused changes in cloud cover over a five-year period can have 85 percent of the temperature effect alleged to have been caused by nearly 200 years of manmade carbon dioxide emissions. They estimated that the temperature effects of cloud cover during the 20th century could be as much as seven times greater than the alleged temperature effect of 200 years worth of additional carbon dioxide and several times greater than that of all additional greenhouse gases combined.

Would it be considered “piling on” to remind Congress that last year’s hurricane season predictions — that is, a 95 percent chance of a very active season — turned out to be a total bust? If hurricane experts armed with supercomputers can’t predict a regional storm season six months into the future, why would anyone think that they can project global climate trends for the next 100 years?

These are just some of the things that climatologists have learned or have been proven wrong about in just the past year.

Given the myriad scientific holes in the manmade global warming hypothesis and allowing for the inevitable future discoveries about climate, it seems quite absurd for Congress to proceed on global warming as if, in Al Gore’s words, “There is no longer any serious debate over the basic points that make up the consensus on global warming.”

The new aerosol study doesn’t show that climate alarmists may be just a little off course — it shows that they may be 180 degrees off.

If manmade global climate change is something worth fretting over — and it’s not at all clear that it is — the aerosol study opens up the possibility for an entirely new hypothesis for global warming with aerosols as the culprit. Yet up to now, the “consensus” crowd has portrayed aerosols in the opposite light as cooling agents.

When so-called “consensus” can be that far off, it would seem that there’s plenty of room for serious debate.

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Steven Milloy publishes JunkScience.com and DemandDebate.com. He is a junk science expert, an advocate of free enterprise and an adjunct scholar at the Competitive Enterprise Institute.