Anyone confused or skeptical about “Climate Change”? Is weather different from climate?
“Climate is what you expect, weather is what you get.”
…. Robert Heinlein, American science fiction author
“Climate lasts all the time, and weather only a few days.”
….. Mark Twain,
Both of these often repeated quotations indicate there is a difference between climate and weather.
Climate and weather should not be confused. People are often heard linking an unusually hot day (Weather) to global warming (Climate Change) or equally absurd suggesting that a particularly cold day (Weather) proves that global warming (Climate Change) is a hoax. Neither is a valid inference.
First of all, weather is what’s happening now, the present conditions typically described by temperature, wind, humidity, atmospheric (barometric) pressure, cloud cover, etc. Weather people get their information by reading instruments such as thermometers (air temperature); anemometers (wind speed), barometers (atmospheric pressure), gas chromatographs (ozone levels), satellite photos (cloud cover), rain gauges (precipitation), yard sticks (snowfall), etc.
Climate on the other hand is commonly defined as the weather averaged over a long period of time. The standard averaging period is 30 years, but the averaging period can range from months to thousands or millions of years depending on the objective. Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elements in a given region over a long period of time. Climate also includes statistics other than the average, such as the magnitudes of day-to-day or year-to-year variations.
So when the “Weatherperson” compares today’s temperature with the “normal” temperature (or the record high and low temperature), they are comparing today’s weather with the historical climate of the region. When the Weatherperson compares the recent annual rainfall with the historical/average annual rainfall, they are comparing this year’s weather with the probably climate for the region based on historical records.
Examples:
Weather data you will often see on TV weather include the current conditions and those expected in the near term (e.g. 5 day forecast) for a local region such as:
• the temperature is 80 F,
• it should rain tomorrow,
• the low today will be 40 F, and
• it is partly cloudy.
Climate data (average weather) you will often see on TV weather for a local region include:
• the average high for today is 50 F,
• it is hot and humid in the summer,
• the yearly average precipitation is 37.45 inches, and
• the average November snowfall is 12 inches.
The weather is usually different than what is expected using climate data because climate data is a long term average. For example, the temperature tends to either be above normal or below normal. When it comes to rainfall and snowfall it tends to rain or snow more or less than what is expected from the average provided by climatology.
Conclusion: As lay-weather-people, we can monitor weather changes by looking at our outdoor thermometer. However to comment on climate change, we need to do the statistical math using weather data over a long period of time (e.g. 30 years) OR rely on credible climatologists/meteorologists (who have no vested interests that might taint their math – i.e. figures lie when liars figure).
More on who might be considered credible climatologists, what causes climate change, and is global climate really changing can be found in “Climate Change Denial: Heads in the Sand” by Haydn Washington & John Cook, 2011.
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