Climate — Science must be able
to say what it means by this,
but it cannot

Dr. Arnd Bernaerts
5 min readApr 6, 2021

Climate is one of the most important words in linguistic usage today. Science in particular uses it extensively. With reference to climate change, a threatening backdrop has been created for the public and politics for years.

But if you want to evaluate changes, you first have to clearly define what climate is. Science has not managed to do this so far, but uses the word like the layman since the ancient Greeks over 2000 years ago. Nobody should let an academic discipline get away with that. She must be able to explain what she is talking about in a comprehensible manner. She has not yet made it.

The following discussion is about the term climate. Therefor it is emphasized that this analysis is not about carbon dioxide, global warming etc., but about the careful use of terms by science. This requires a comprehensible description of the meaning of the word, a definition, fit for use in scientific research, and in communication with the general public. As long as science has failed to do it, or has done not sufficiently, the term climate should not be used by them at all.

The next clarification is simple and decisive: the word climate in the layman’s world and the word climate in modern science. The layman uses the word climate as he thinks it makes sense for a conversation. Since there are about 5 billon adults on earth, everyone uses it as he needs it and adapted to the situation in each case. One day like that, another day like that. It has worked well for more than 2000 years to this day — In everyday life. In science such an approach is a catastrophe and an evidence of incapacity of an academic discipline.

While layman use the world climate as it pleases, science is aware that it needs one. The starting point is that most relevant international treatise in this field, the UN Framework Convention on Climate Change (1992, UNFCCC) offers none, although one hundred years ago an International Meteorology Organisation (now WMO) defined climate as average weather and still does. The Intergovernmental Panel on Climate (IPCC), turns the meaningless “average weather” into an inflated nonsense, namely, according its Glossary:

“Climate in a narrow sense is usually defined as the average weather, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. (cont.)”

IPCC’s approach is a bundle of helplessness and superficiality. The most outstanding is to speak of ‘average weather’, but not to say what ‘weather’ is, That has to be clearly defined in order to be able to speak and discuss about climate in a comprehensible way. This low blow is followed by the second when the UNFCCC only speaks of ‘climate change’ and has neither said how weather and climate should be defined. Although the Convention reaches soon its 30th anniversary, science doesn’t even see these weaknesses.

Presumably less than handful scientists have requested more clarity. Back in 2005 Prof. Roger Pielke Sr. wrote a post (Fn1): “What is Climate? Why Does it Matter How We Define Climate?“, and a few years later complained that „The terminology in the field of climate and environmental science is filled with jargon words and the misuse of definitions”.

A just few weeks old paper either regards that the term “climate change” turns out to be scientifically unjustified, specifically, as it is it a pleonasm as climate, like weather, which has been ever-changing. Prof. Demetris Koutsoyiannis assessments is of little help either. Full paper may be downloaded here. (Fn.2)

Even these two rare critical authors fail to recognize and distinct clearly, that for scientific work the weather describes physical observations, while the word climate, present only records on numerical statics. For science weather is based on a physical background; which consists of many dozen components and can be described in more than hundred ways (see HERE). Science is complete silent on this aspect, ignoring in research matters it cannot be left open which are meant. Mixing it up with the layman’s use of both words weather and climate is thoughtless, dumb and dangerous.

The failure of science to come up with appropriate climate definitions misleads the general public and politicians on how the prevent man-made changes in the atmosphere should be secured (more HERE).. For them it is high time to show that they can reasonably define what they are talking about and claim to understand it. The “use of words without fixed meaning” in environmental research must find an end. For sure, John Locke (1632–1704) would repeat this demand clearly again today.

People defend your ‘climate’ — as you use it for 2000 years

FN1: More at:, and

Fn.2: file:///C:/Users/User/AppData/Local/Temp/water-13–00849-v3–1.pdf