- The authoritative voice & The term: Climat
Posted on 01.November 2009/AB
The World Meteorology Organization is a specialized
agency of the United Nations (UN). Within the UN system
the WMO understand itself as “the
authoritative voice on the state and behaviour of the
Earth's atmosphere, its interaction with the oceans, the
climate it produces and the resulting distribution of water
WMO originated from the International Meteorological
Organization (IMO), which was founded in 1873. More than 180
States are members of WMO.
The WMO website does not spend much space on the term climate and weather.
We failed to find a Glossary.
However the WMO site has a theme-section,
which include the two terms in question. Concerning weather
the section “Weather” offers no explanation but has the
opening sentence: “Everyone is interested in the weather”,
while subsection: What is Climate
begins with the sentence: “At the simplest level
the weather is what is happening to the atmosphere at any
In the same section the Organization offers for
climate three options namely:
in a narrow sense Climate is usually defined as the "average
in a more rigorously way, Climate is the statistical description in terms
of the mean and variability of relevant quantities over a
period of time (C), and
in a broader sense, Climate is the status of the climate system which
comprises the atmosphere, the hydrosphere, the cryosphere, the
surface lithosphere and the biosphere (D).
None of the items is very clear and can hardly be regarded as explanatory.
Here is a provisional brief comment on each item (A-D):
It is not very enlightening and not necessarily correct,
The boundary between the Earth’s atmosphere (Kármán
Line) and outer space is at an altitude of 100km, but weather
happens only up to 17km (equator) and 7km (poles).
The reference to ‘any given time’ is questionable,
as any time period longer than a few days, would
–according the next definition (B)- be: climate.
Science can describe and work with ‘average weather’
only by means of statistics of physical observations. Once a
statistic it remains a statistic.
There is actually no difference between climate in a
“narrow sense” (B) and in a more rigorously way (C), but a
confirmation average weather shall mean a statistical
description, whereby the reference to “the mean and
variability of relevant quantities” is completely vague and
It is hardly to see what is meant with “broader
sense” and an example of a case explaining something in
A formula: Climate is the status of the climate system,
makes no sense.
According the given explanation of climate (B & C),
climate system would mean
weather system, or
statistical description of relevant quantity system,
is in no way helpful.
The word status indicates a situation, and not longer
period of time.
The reference to the ‘climate system’ is at least
confusing, as the elsewhere defined term emphasize the
‘interaction’ among the subject fields.
Has it be left unmentioned because status and interaction do
not fit well together?
WMO has had more than 130 years of time to formulate a
clear and understandable language. The way they define,
explain, and use the layman’s
terms weather and climate is hardly convincing. A
scientific approach is invisible. Do they need another century
to do better?
UNFCCC, Article 2, para.3; . "Climate system"
means the totality of the atmosphere, hydrosphere,
biosphere and geosphere and their interactions.
National Snow and Ice Data Center, http://polar.ncep.noaa.gov/seaice/climatology/months.html