Semantic Clarity

Looking for something else on the Internet I unhearted a wikipedia page with the sinister title Climate change denial - now, Aug 29 2008, the article is being considered for deletion, so the link may be dead when you read this.

As one can easily imagine, the article makes the point that anyone denying that human activities are causing a catastrophic rise of global temperature must be a corporate stooge or some other sort of evil man.

But what strikes me is the huge semantic confusion, not only in this paper but in many more - especially on the alarmist side. Semantic is important because, to make a condensed Jeff Goldstein, those who control the narrative control the facts. If we let the alarmist side set not only the term of debate, but the very meaning of words, the debate is lost no matter what (the facts are).

So let's give a few definitions for a meaningful debate.

Climate Change - By all resonable standards of English language, this is the most neutral statement. It simply means that the quantities describing Earth's climate (average temperature in particular) are not constant with time; it says nothing about the sign, magnitude and rate of the change, neither about its causes or consequences. The statement is true, but it is also so vague to be of nearly no use: climate has always been changing since an atmosphere appeared around our planet, and there is nothing unusual about the change occurring also in this age. The use of this expression to imply a decisive role of human activities in climatic changes is linguistically incorrect and intellectually dishonest.

Global Warming - This expression is much more specific: it says that average global temperature (at the surface) is rising, leading to a warmer world. Also in this case, the expression itself contains no indication about the magnitude and rate of warming, and neither about causes and effects of the phenomenon. Again, this expression does not imply a human impact on climate; however, it somewhat implies a recent and/or unusual phenomenon.

Temperature Anomaly - The deviation of temperature, for the region of interest, from the average temperature calculated in a chosen reference timeframe (baseline). Often, anomaly values are normalized - divided again by the baseline value. The choice of reference timeframe alters significatively the baseline position and thus the anomaly values.

Anthropogenic Global Warming - Global warming, but with the cause specified: generated by humans (in layterms, man-made). This is the correct expression to indicate an increase of global average temperature produced entirely or at least for a significant fraction by human activities (in particular, emission of carbon dioxide in the atmosphere).