When we hear something in the news about record cold temperatures, or massive snowstorms, it’s tempting to scoff, “So where’s that so-called global warming now? I could use a bit of that!”
Well, so much for global warming, right? Wrong.
At the same time that we may be having record snowfalls, Earth’s temperature continues to creep upward. We just don’t notice it. That’s because weather is very different from climate. They are not one and the same.
Weather is what our minds are designed to remember. It describes conditions from day to day, week to week, and even from year to year. Weather is that one sweltering week in July, or the coldest November on record, or the snowiest winter ever.
Climate, on the other hand, is nearly impossible for us to remember. It describes the average weather conditions over tens, hundreds, and even thousands of years. Climate is the average temperature or rainfall in a certain place, based on what it’s been like for decades.
All of us like to complain about how weather forecasts are always wrong. But weather forecasting is a tough job, because weather is inherently chaotic. It’s been proven mathematically that it’s impossible to predict the weather more than two weeks in advance.
And in reality, two weeks is on the optimistic side. Weather is by nature unpredictable, driven by unforeseeable forces. We all know that. But what many don’t know is that climate is relatively predictable over time scales of decades to centuries, driven by forces we do know about: changes in the amount of energy we receive from the sun and, more recently, what our emissions of heat-trapping gases are.
So it’s no wonder, if we aren’t aware of the fundamental differences between weather and climate, that some doubt scientific claims about climate “prediction.”
Want more? Here's a great explanation of how we can have a cold summer and global warming at the same time from the Smithsonian and another from NASA.