Ice is one of nature’s thermometers, telling us whether or not the temperature of water is above or below 0°C (32°F). When things get hotter, it melts more and faster; when things cool down, water can freeze and ice accumulate. In general: more heat = less ice; less heat = more ice.
One of the places on Earth we find lots of ice is the sea surface in the Arctic, and when we graph its extent the first thing we notice is the seasonal pattern: in summer/fall there’s more heat, less ice; in winter/spring less heat, more ice.
I happened across a video about global warming basics, which I think is pretty good. What’s your opinion?
Climate is the rules of the game;
weather is the roll of the dice.
One of the things I emphasize most often and most strongly is that, while global temperature is forever fluctuating, it’s also showing a trend.
I read Shakespeare and the Bible, and I can shoot dice. That’s what I call a liberal education.
— Tallulah Bankhead
People have been playing with dice for at least 5,000 years. They come in all shapes and sizes, but have a common purpose: to generate randomness. When dice are rolled (or “thrown” or “cast” or “tossed” or “shot,” depending on your verb of choice) many results are possible, but what actually happens isn’t known until it happens. Dice (or one die, to use the singular) are the world’s original random-number generator. We may not know what they’ll give but at least we can figure out what to expect.
If they’re fair, that is.
I started the “Global Warming Basics” posts specifically to help people who are interested in what’s going on, wondering whether we should do something about it and what, but want to keep things simple. My purpose isn’t to turn you into a scientist — it’s just to give you enough information to make sense out of what you hear about the subject. Alas, that can be all too difficult, because so many people, and politicians, are willing to distort the truth.
Perhaps the most basic question for a lot of people is “What has changed?” Has climate changed already? In what way? What have we seen in the last few decades that concerns us? What did we see last year? Last month? What’s been going on, really?
Let’s take a look.
Heat is a form of energy, but it’s certainly not the only one; there are so many I won’t bother you with a list. In any complex system — an automobile engine, the human body, planet Earth — energy is constantly changing from one form into another, so if some object has energy (and it always does), sooner or later that energy will distribute itself among the various available forms. Since one of those is heat, in general terms when you gain energy you’ll end up with more heat, when you lose energy, there’s less of it to go around and that means less can be heat.
Another important form of energy is electromagnetic waves. It’s a fancy science term but in at least one form it’s something we’re all familiar with: light. More generically we can call it radiation.
Even when climate is constant, unchanging, the weather is not.
Temperature is one aspect of weather (and therefore of climate), so it’s in constant flux, whether we’re looking at a single location or an average over the whole globe. The changes we observe, whether of ever-changing temperature or any other weather variable, can be divided into two broad categories: signal and noise.