A couple of weeks ago we received a communication of the latter type that concluded by saying "your site is an embarrassment to the word 'science'" I can only hope that your server is based in California and that a terminal blackout kills your site for good."

Knowing full well that we are as science-based as a site can possibly be, we were curious about what it was that so incensed the writer, so we wrote to him in an attempt to find out.  We asked him if he could "give us just one or two examples of what you think is untrue or illogical about our website," noting that "it's much easier to focus on a specific matter than on a more nebulous general condemnation."

In response, the writer, who identified himself as an "environmental scientist," said he was irritated at (1) our "claiming that CO2 is responsible for increasing longevity in humans," and (2) our "claiming that a limited number of local mean temperatures are decreasing, and therefore global warming is a myth."

Upon receiving these specific complaints, we went to our web site to check out their validity; for we agreed with our correspondent that if we truly had said what he said we had said, we were indeed claiming too much.

To investigate the writer's assertion that we claim that the ongoing rise in the air's CO2 concentration is responsible for increasing human longevity, we went to our Subject Index, clicked on "L" to find "Life Span," and then clicked on "Human," where we found six specific entries listed.  Two of these entries dealt with temperature effects on human mortality (as opposed to CO2 effects) and were not germane to the question at hand.  The other four, however, did indeed broach the "irritating" subject.

In the first entry, Disability and Death in the Elderly, we found where we had said that we believed the cause of the ever-improving situation with respect to human disability and longevity must be ever-increasing concentrations of health-promoting and disease-fighting substances in foods, which is something that may well be driven by the ever-increasing CO2 content of the air.  However, we stated very clearly that "this suggestion is far from proven."

In the second entry, Oxidative Stress and Ageing, we found where we had said that atmospheric CO2 enrichment stimulates modest increases in certain health-promoting antioxidants and cancer-fighting substances in plants, whereupon we asked rhetorically if this phenomenon may have had something to do with the great lengthening of the human life span that had occurred over the past century or so, during which time the atmospheric CO2 concentration had concurrently been on the rise.  We answered this question by saying "no one knows for sure."

In the third entry, Live Long and Prosper ... With More CO2!, we found where we again had briefly mentioned the potential link between increasing human longevity and the propensity for atmospheric CO2 enrichment to moderately enhance plant concentrations of such things as vitamins A and C and certain substances that have been proven to be effective in fighting a number of human cancers and viral diseases.  But as for cause-and-effect, we had only said "these connections are very intriguing."

In the fourth entry, Why Are We Living Longer?, we found where we yet once again had said much the same thing, noting that the potential connection between increasing human longevity and the role of the ongoing rise in the air's CO2 concentration in enhancing the health-promoting properties of food is but an "intriguing possibility." Hence, nowhere could we find a single instance where we had claimed, as our correspondent erroneously said we had, that "CO2 is responsible for increasing longevity in humans."  And that is our position to this day; we feel this suggestion is an intriguing possibility, but far from proven.

To investigate the second of the allegations made by our irritated correspondent, we went to the home page of our web site, which also serves as the cover of our weekly CO2 Science Magazine, to have a look at our Temperature Record of the Week feature, where our correspondent says we claim that because a limited number of local mean air temperatures are decreasing, "therefore global warming is a myth."

The closest thing we could find to this claim in the brief front-page synopsis of our Temperature Record of the Week feature was the nearly-always-identical concluding statement that sums up the result for the specific site highlighted each week -- "Not much global warming here!" -- which clearly says nothing about the entire rest of the world.

Probing further, we clicked on the highlighted words Temperature Record of the Week to see what might be lurking a little deeper in our web site relative to this matter.  The first sentence of the explanatory material that subsequently appeared states that "to bolster our claim that, There Has Been No Global Warming for the Past 70 Years, each week we highlight the temperature record of one of the 1221 U.S. Historical Climatology Network stations."

This statement indicates that we do indeed claim there has been no net warming of the globe over the past seventy years; but it also indicates that we do not base this claim on our Temperature Record of the Week feature, which we say is used to bolster this claim, i.e., to provide additional evidence for it.  The real reasons behind our claim can be found by clicking on the highlighted words There Has Been No Global Warming for the Past 70 Years, which brings up an Editorial that discusses this claim in greater depth.  And the first sentence of that Editorial directs one to a prior Editorial entitled The Global Surface Air Temperature Record Must Be Wrong, where even more reasons for our position on the subject are discussed.  In addition, two subsequent Editorials describe yet other aspects of the issue: Two Types of Tree-Ring Response to Atmospheric CO2 Enrichment and Their Implications for Reconstructing Past Trends in Earth's Surface Air Temperature and Temperature Reconstructions Based on Plant-Climate Interactions Are Inaccurate If Atmospheric CO2 Varied Over the Period of Reconstruction.

Of course, you can never win an argument with some folks, no matter how logically you present your case.  When we pointed out what we had actually said on our web site to our inquisitor, which was clearly not what he said we had said, he merely replied we were "misinformative" and "misleading," suggesting it would "be more honest to put those disclaimers in a large 24 font, bold, red banner on the top of each of your pages."

In this suggestion, our correspondent actually would have had a point, if we had truly made a dramatic claim of the sort he unjustifiably said we had, which, of course, we had not.  A good example of where his advice might have better been directed is identified by the National Academy of Science's Committee on the Science of Climate Change.  In their recent report to the President of the United States, they state that, with respect to the Working Group I report of the Intergovernmental Panel on Climate Change (IPCC), "the Summary for Policymakers reflects less emphasis on communicating the basis for uncertainty and a stronger emphasis on areas of major concern associated with human-induced climate change," which is another and more polite way of saying that the IPCC Summary for Policymakers needs more realism and less scaremongering.

Yet even the NAS Committee on the Science of Climate Change succumbed to the temptation to do what they criticized the IPCC for doing, when in the very first sentence of the summary of their report they boldly claimed that "greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise."  To the committee's credit, caveats followed quickly on the heels of this claim; but many of the press refused to acknowledge them.  As noted by committee member Richard Lindzen in The Wall Street Journal, "CNN's Michelle Mitchell was typical of the coverage when she declared that the report represented "a unanimous decision that global warming is real, is getting worse, and is due to man.  There is no wiggle room."

Well, it's easy to carp at other folks, and we don't want to do too much of it; for in the heat of debate one often says things one would significantly temper given more time for reflection.  It is possible, for example, that we do have some statements on our web site that overstate the case for some proposition, although we are not aware of any and the two specific items identified by our correspondent clearly do not merit this criticism.  Nevertheless, it behooves all of us to carefully measure our words and try as best we can to reflect an appropriate degree of certainty or uncertainty in all we say, which is clearly something the IPCC and a certain critic of ours have yet to learn.