Weather and climate aren’t the same thing



It’s been a while, but I heard some guy on the radio argue the other day that the frequency of inaccurate weather forecasts by professional meteorologists is evidence that the claims regarding global warming made by climate scientists are pure nonsense.

Wow! I had almost begun to think that theories like that one had long since been filed away with myths about a pot of gold at the end of the rainbow.

It reminds me of something I jotted down from some source or another a few years ago. It read as follows:

Scientists can’t even predict weather…Since modern computer models cannot with any certainty predict the weather two weeks from now, how can we rely upon computer models to predict what the Earth’s climate might be like a hundred years from now? They can’t! Yet people like Al “Carbon-Credit” Gore want you to believe that these models can predict the future. I bet I can do at least as well with a crystal ball.

Global-warming skeptics love to make the argument that the changeability of weather forecasts in the short term betrays the claims by climate scientists that potential disaster lies just a few decades away as the planet heats up.

The fundamental problem with such skepticism is that weather and climate are not the same thing. TV meteorologists are not climatologists. Sometimes it’s more difficult to predict whether Sunday’s ballgame will be rained out than whether melting glaciers will cause sea levels to rise by the time your toddler is in high school.

As we see in this piece from the website Skeptical Science:

A change in temperature of 7 degrees Celsius from one day to the next is barely worth noting when you are discussing weather. Seven degrees, however, make a dramatic difference when talking about climate. When the Earth’s average temperature was 7 degrees Celsius cooler than the present, ice sheets a mile thick were on top of Manhattan!gical Organization.

In truth, the claim regarding short-term weather forecasts vs. long-term global warming is based more on an appeal to emotion than fact. The inference is that climate predictions, decades into the future, cannot be possibly right when the weather forecast for the next day has some uncertainty.

Actually, short term weather forecasts are fairly accurate and have improved dramatically over the course of my lifetime. However, slight errors in initial conditions make a forecast beyond two weeks nearly impossible.

Atmospheric science students are taught “weather is what you get and climate is the weather you expect”. That’s why this common skeptical argument doesn’t hold water. Climate models are not predicting day to day weather systems. Instead, they are predicting climate averages.