If it's been chillier than usual in your area lately, you're not alone. Cold weather swept across the continent last week, leading to plummeting temperatures and too much snow to handle in many cities across the US and Canada. It's not just chilly here, either. While they're entering summer in the Southern Hemisphere, the coldest temperature ever recorded was recently logged in Antarctica - minus 135.8 Fahrenheit, or minus 93.2 Celsius.
When the mercury starts to fall, some people may wonder why it's so cold out if we're supposed to be experiencing global warming. Can climate change really be happening, if we're shivering our way through late autumn? The short answer is Yes.
When you're talking about the impact of climate change, it's important to understand the difference between the climate and the weather. The weather is what's happening right now. It tells us about the current temperature, wind speed and direction, humidity level, cloud cover, precipitation and so on. The climate tells us about the weather patterns in an area over a longer amount of time. It tells us things like what the average temperature and precipitation accumulation are in a specific place over several years, decades or centuries.
Another way to put this is to say that the weather is the day-to-day variation, while the climate is the long-term trend. Here is a short and easy-to-understand video that explains the difference:
Of course the weather is colder in the winter than it is in the summer. And of course, we sometimes see temperatures that are unusually cold, just as we sometimes see temperatures that are unusually hot. Taken by themselves, they don't tell us how the Earth's climate is changing. Only measuring trends over time can tell us what's happening, and help us to predict what may happen in the decades ahead. Those trends are very clear: the average temperature on our planet is rising, and there's a strong scientific consensus that humans are causing it.
While the idea of global warming may sound appealing on a cold winter day, the evidence is pretty strong that it's actually not a good thing for plants, animals and people. It's important that we don't become complacent, just because it isn't warm out today.