Prof. Disbrow takes down deniers with just the facts
It’s getting hotter. Everyone knows it. Except, of course, that it’s actually getting colder. Everyone knows that! Heavier rains, longer dry spells. The drought in California? Tornadoes touching down all over the Tennessee Valley…? What exactly is going on here?
What’s going on is climate change.
The term “climate change” has taken on a lot of baggage over the past few years, so we’ll start with the dictionary.com definition: “ ‘Climate Change’ noun; a long-term change in the earth’s climate, especially a change due to an increase in the average atmospheric temperature.”
Reading that, your brain might be tempted to substitute the word “weather” for “climate.” That’s a natural thing to do, because we talk about the weather all the time, and not so much about the climate. So, what’s the difference?
The difference is that “the weather” is the state of the atmosphere where you are at a particular moment. Is it hot? Cold? Sunny? Raining toads? That’s the weather.
“Climate,” on the other hand, is the long-term pattern of weather in a particular area. For example, when you say, “It’s really cold in Alaska,” you are really referring to the climate there, which is a long-term picture of what the weather is likely to be on any given day in Alaska: cold.
Here in Chattanooga, when I was a kid, the climate was basically, “Too hot to get out of school at all in the winter.” These days, our climate seems to be “Cold/rainy enough to close the schools regularly.” That’s a big change, and just in my lifetime. So:
• Weather is atmospheric conditions where you are.
• Climate is the long-term pattern of weather in a particular place.
• Climate change is the long-term differences in climate everywhere on the earth. (i.e., global changes in patterns of patterns)
A decade ago, a certain Tennessee politician made a bit of a stir with a book/movie about “global warming.” Just to be clear, global warming is not climate change. It is, however, one of the drivers of climate change. Heat is energy, and when you pump energy into something, it changes the behavior of that something. (Like when you give a toddler a 7-pound gummi worm to gnaw on right before bedtime.)
To be sure, there are a lot of different sources of heat that get pumped into the atmosphere: The sun’s energy output fluctuates, the Earth gets closer to and farther from the sun as it swings through space in its orbit, and volcanoes go off regularly, pumping heat into the atmosphere. But none of those sources can match what humans have been doing to the planet since the start of the industrial revolution.
The main thing we’ve been doing is shoving carbon dioxide (CO2) into the atmosphere. This is a “greenhouse” gas that traps heat from the sun. So, rather than radiating back into space, more heat gets trapped, warming things up and adding energy (“gummi worms,” if you will) to the atmosphere and oceans.
There are other greenhouse gases that cause warming, but CO2 is the main troublemaker. Since 1960, the amount of CO2 in the atmosphere has gone from about 320 parts-per-million (ppm), to 402 ppm as of last month. (Climate scientists agree that 350 ppm is the maximum “safe level” for atmospheric CO2. Visit co2now.org for the latest numbers.)
Combine this with the fact that we’ve been chopping down trees nonstop for the last few centuries and you’ve got a situation where CO2 builds up in the atmosphere, trapping more and more heat. (Remember, trees eat CO2 and sunlight and turn them into oxygen, which we actually need to live.)
This leads to a dangerous feedback loop: The atmosphere heats up, which melts glaciers and polar ice. That ice, which is white and very reflective, is no longer around to bounce sunlight back into space. So more heat gets trapped, which makes things warmer, which...well, you get the idea.
As things get warmer, that energy drives stronger storms and changes the temperature of the oceans. So, you get more powerful tornadoes and hurricanes and changed environments in the ocean. This can cause deadly algae blooms and destroy the habitats that fish previously called home.
If things continue the way they are, the EPA predicts that average U.S. temperatures will rise between 4 and 11 degrees Fahrenheit by the year 2100. What can we do to prevent it? Come back in a few weeks and we’ll talk about that very thing.
Steven Disbrow is a computer programmer who specializes in e-commerce and mobile systems development. He’s also an entrepreneur, comic-book nerd, writer, improviser, actor, sometime television personality and parent of two human children.