My son has spent years lecturing me about the actual density of carbon dioxide, or CO2, in the atmosphere, and the overall effect such a small percentage can have on global warming.

And I, thinking I heard wiser (or at least older) voices, have ignored him.

Turns out he’s at least partly right. Carbon dioxide, by volume, represents less than 0.004 percent of earth’s atmosphere. Water vapor, on the other hand, represents 4.0 percent; both are greenhouse gases, or GHGs.

As are methane (0.00018 percent), nitrous oxide (0.00003 percent), ozone (0.000001 percent), and those nasty fluorocarbons (coolants and propellants, at 0.00000005 percent).  

But he’s right for all the wrong reasons, because even though it’s clear that the density of a gas in the atmosphere is not a primary global warming trigger, it’s also evident that mankind’s activities for the last 100 years have made a significant difference in global weather patterns via the amount of CO2 released, primarily by burning fossil fuels (a release that remained negligible during all the years prior to the Industrial Revolution).

For example, even though the methane being released from thawing of the Arctic permafrost may be a much greater danger to climate stability than CO2 at this point, it is equally as clear that CO2 can’t be left out of any sensible equation. In fact, as resident expert Joe Romm points out, “Methane is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 72 times as potent over 20 years!”

His remark, taken out of context, would suggest that, in the short term, we should perhaps be more worried about methane than CO2. But it’s this kind of thinking – encouraged by studies like that from Oregon University – that may lead us to recklessly exploit the ability of the planet to “bounce back” from CO2 burdens; a theorem expressed by study author Andreas Schmittner, who said, “Our study implies that we still have time to prevent (the worst of global warming) from happening, if we make a concerted effort to change course soon.”

This, if true, flies in the face of scientific consensus, and I’d hate to think that such a point of view is winning, because it skews the facts as only “fuzzy” science can, lends unwarranted credence to the pronouncements of global warming deniers, and makes the road for real climate scientists seem all uphill.

I’m thinking in particular of NASA scientist and chief global warming spokesperson James Hansen, who would disagree with the sentiment expressed by Schmittner and reiterate that such speculation undermines the case for anthropogenic (man-made) climate change while doing nothing to change the actual science.

This is the same Hansen who very recently warned President Obama that approval of the Keystone XL oil pipeline project (which would allow even greater exploitation of dirty Alberta tar sands) was, “Game over for the climate.”

Hansen has often quoted Albert Einstein, who said that thinking and not acting is a crime. Hansen is seldom afraid to act, and even less afraid to call a spade a spade. In fact, it is Hansen’s new paper, “Climate Variability and Climate Change: The New Climate Dice”, which describes increasingly intense heat waves in Moscow (2010) and Texas (2011) as “climate outliers” that should make people aware how fragile earth’s climate really is, and how easily it can be tipped over into something treacherous and life-threatening.

Hansen has always been quick to note that the greatest barrier to getting humans to recognize how deeply their behavior has affected climate is the natural variability of the weather itself. And reports like the one coming out of Oregon University merely lend credence to that natural human tendency to deny or obfuscate. How can the climate be warming if winter is so darn cold?

As Hansen and colleagues Drs. Makiko Sato and R. Ruedy note: “Science does show that business-as-usual fossil fuel emissions will cause atmospheric CO2 to continue to increase rapidly. The increasing greenhouse gases will cause the rapid global warming of the past three decades to continue, and this warming will cause the climate dice to become more and more loaded with greater and greater extreme events. The probability that this conclusion is wrong is about as close to zero as one can get.”

Those are not the kind of odds we want to contemplate, particularly if we have children and grandchildren who will be forced to occupy the planet long after we are gone.