Climate Change? What Climate Change?

KANGERLUSSUAQ, GREENLAND - SEPTEMBER 01: (ISRAEL OUT) Ice boulders left behind after a flood caused by the overflowing of a l
KANGERLUSSUAQ, GREENLAND - SEPTEMBER 01: (ISRAEL OUT) Ice boulders left behind after a flood caused by the overflowing of a lake, east to the town of Kangerlussuaq on September 01, 2007 Greenland. Scientists believe that Greenland, with its melting ice caps and disappearing glaciers, is an accurate thermometer of global warming. (Photo by Uriel Sinai/Getty Images)

About that climate-change argument.

"Snowstorm Barrels into Northeast" was the headline on the New York Times at the door; "Rainless January sparks fears, fires," proclaimed the lead story in the San Francisco Chronicle lying next to it. At some point, the argument begins to seem absurd.

But, it is easy to find individuals and groups who maintain that the globe is not really warming; the climate is not really changing; it's all just part of Mother Earth's cycle through her planetary life. Climate change deniers even have their own formal designation -- which this writer just now learned about -- Anthropogenic Global Warming (AGW) Deniers. By whatever name, deniers are those who think humans have nothing to do with climate change, so we might as well go right on doing what we're doing forever.

Some of us worry that forever could come sooner, rather than later, if we don't pay attention.

Watching the ice melt in arctic regions, wishing for air conditioning in San Francisco in January -- those things suggest that paying attention to fossil fuels probably makes sense. Carbon dioxide sent into the air by the burning of fossil fuels is one of the proven culprits regarding global warming. One gallon of gas, when burned, puts 16 pounds of CO2 into the atmosphere; the math is pretty easy to do.

The issue even wound up on a recent front page of theNew York Times' Sunday Business section. A group of business leaders representing vastly differing political and philosophical views all agreed on one point: Climate change is leading to major economic costs. Headlines suggesting this caught the attention of the business world: "Flooded properties. Lower crop yields. Stalled trains."

We, non-deniers, worry about fossil fuels (which, of course, does not keep us from driving cars), but also about little things, like aerosols. Natural aerosols? Lovely. They translate into mist and fog and Old Faithful Geyser. It's the un-naturals that are problematic -- those tiny particles that spill into the atmosphere every time you reach for that handy aerosol can.

"Scientists call airborne particles of any sort -- human-produced or natural -- aerosols," explains Carol Rasmussen on NASA's "Vital Signs of the Planet" site.

The simplest effect of increasing aerosols is to increase clouds. To form clouds, airborne water vapor needs particles on which to condense. With more aerosols, there can be more or thicker clouds. In a warming world, that's good. Sunlight bounces off cloud tops into space without ever reaching Earth's surface, so we stay cooler under cloud cover.

But the bad news is that there are different kinds of aerosols, and different kinds of effects that are hard to predict -- so cloud cover becomes sooty haze, and what bothers the people walking outdoors in Beijing can affect people fanning themselves in San Francisco in January.

Which brings us back to the news headlines:

"Storm Batters Coastal New England Town."

"California's Hottest Year On Record."

"China's Air Pollution at Danger Levels."

Denial is getting harder with every sunrise.