The atmosphere is so unstable that a butterfly flapping its wings can, famously, change the course of weather patterns. This so-called “butterfly effect” also means the reliability of weather forecasts drops sharply beyond 10 days.
In addition, there are strong fluctuations in temperature. with increases tending to be followed by decreases, and vice-versa. The same pattern holds true over months, years, and decades.
“This natural tendency to return to a basic state is an expression of the atmosphere’s memory that is so strong that we are still feeling the effects of century-old fluctuations,” says McGill University physics professor Shaun Lovejoy. “While man-made atmospheric warming imposes an overall increasing trend in temperatures, the natural fluctuations around this trend follow the same long memory pattern.”
