Having dipped into Stephen Schneider’s articles and books many times over the past thirty years, including published commentary and research on climate change in such professional journals as Science, I feel compelled to spring to his defense against the implied charge of promoting oversimplification and/or distortion of scientific findings as a tool of advocacy or for advancing a political viewpoint. Schneider’s voice was as sane, sound, honest, and balanced as you will find anywhere in the public discussion of global warming. Nowhere does he overstate the likelihood of a catastrophic outcome due to the historic greenhouse-gas rise. In fact, he has always taken pains to avoid overstatement, often preferring to understate the case for severe or highly disruptive effects rather than the reverse.

He is, however, absolutely right that you can’t confuse the media with discussion of “doubts… caveats… ifs, ands, and buts.” The media automatically puts everything through a filter that removes fine shades of meaning. On the other side of that filter what comes out is Yes/ No and White/ Black. Any wavering or indication of doubt about the reality or seriousness of global warming will generally be classified, written up, and played by the media as a “No” answer to the question of whether warming is serious. Scientists have to paint the picture of a globally-warmed world in stark black-and white. It really is necessary, as Schneider said, to “offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts….”

Absent such a “Hell-and-High-Water” approach, there is little hope of winning the information/ disinformation war over global warming that Ross Gelbspan, a former editor of the Boston Globe, in his 1990s book The Heat is On aptly called “the battle for the control of reality.” Does a responsible television meteorologist waste time with caveats, ifs, ands, and buts if a likely tornado signature has been spotted on doppler radar in association with a potent supercell thunderstorm racing into a heavily populated area? No, the meteorologist tells people to get out of the way and into safe shelter, even though he or she knows most viewers won’t see a tornado; possibly none will. The sobering aspect of the matter is that even though the worst possibilities of climate change may not materialize, the effects are nevertheless likely to be very serious, and ignoring the threat opens the entire world to eventual catastrophe much worse than a typical populated area today would sustain from a direct hit by a mile-wide, F5 supertornado. Taking out solid insurance against the worst possibilities of CO2-driven global warming would be more than a wise move; any other response is terminally stupid.

Here’s what we have to consider. With atmospheric CO2 approaching 400 ppm and rising at a rate of ~2 ppm/year, the best scientific evidence available (SEE: Hansen et al., “Target Atmospheric CO2: Where should Humanity Aim?”) argues that the world is headed for long-term climate changes that will carry conditions on the face of the earth into a realm far outside the range of variation of the historical climate to which our species and most other life forms on the planet are adapted. Essentially a different planet looms. It seems that Antarctic glaciation only commenced about 34 million years ago after a sustained drawdown of atmospheric CO2 due to increased geochemical weathering led CO2 levels to fall into the range of 425 plus or minus 75 ppm. More CO2 than anything in that range very likely places both the Greenland and Antarctic ice sheets out of long-term equilibrium with today’s warming climate, destined to mely away irreversibly unless we bring CO2 back into the range of 300-350 ppm. Perennial Arctic sea ice is already almost history. Hansen et al. flatly state: “If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm…. If the present overshoot of this target CO2 is not brief, there is a possibility of seeding irreversible catastrophic effects.”

Yet for well-founded statements like this, based on evidence for very high long-term climate sensitivity due to the major carbon-cycle feedbacks and the large planetary albedo changes to be expected from disappearing ice sheets, Hansen is now being ignorantly or foolishly dismissed as a “catastrophist” in some quarters. Although Stephen Schneider never earned the label of “catastrophist,” he was an eminently sober realist, as is Hansen himself, and it’s unlikely that he would disagree with the assessment of Hansen et al. on what the future holds. When someone as cautious and cool-headed as Hansen makes such pronouncements, they must be taken very seriously indeed, especially considering Hansen’s long record of accuracy in predicting effects of climate change. Schneider was one of the few scientists alive who could stand in company with Hansen in this arena, and he will be sorely missed.

He will be sorely missed.