With Earth Day coming up tomorrow, millions of American schoolchildren have no doubt been commanded to write an essay on global warming to prove they’ve been properly indoctrina– I mean, educated on the topic. And, kids being kids, I’m sure many of them procrastinated and are now scrambling to find enough information to put together the required thousand words or so.
Fear not, kids. I’m here to help with a Global Warming Q & A. Feel free to plagiarize at will.
What does “global warming” mean?
It means the planet is slowly getting warmer. According to some scientists, it’s happening because of something called The Greenhouse Effect. Here’s how it works: human beings are emitting a lot of carbon dioxide, so it’s building up in the atmosphere and trapping heat. It’s a bit like when your car sits in the sun with the windows up.
So carbon dioxide must be at record levels.
Absolutely. The current concentration is 385 parts per million, which, as Al Gore pointed out in An Inconvenient Truth, is the highest it’s ever been … except for when it was a lot higher.
A lot higher?! What are you talking about?
I’m talking about the periods in earth’s history that Al Gore doesn’t talk about. Actually, that would be most of the earth’s history, at least if we’re talking about the last 600 million years.
CO2 was higher than 385 parts per million for most of earth’s history?
Heck, yes. We’re talking about crazy-high concentrations: 4500 parts per million in one era, 3000 parts per million in another, etc.
Wow! It must’ve been hotter than blazes!
Nope, not always. Sometimes it was hotter than today, and sometimes it was colder. Sometimes the earth’s temperature plummeted even while carbon dioxide was going way up.
But how can that be? You just said carbon dioxide produces heat.
No, I said some scientists say that. But as for an explanation, apparently the laws of chemistry and physics changed over time.
That doesn’t seem possible.
Well, let’s try this, then: Carbon dioxide and the earth’s temperature dated for a long time, often breaking up and going their separate ways. But they decided to get married several thousand years ago and now travel together.
Okay, so at least in relatively recent times, when carbon dioxide goes up, it caues the temperature to go up.
Actually, the temperature goes up first, then carbon dioxide goes up. Carbon dioxide is so powerful, its heat-producing effects can go backwards in time.
But … uh … so is higher CO2 causing warmer weather in modern times or not?
That’s what some scientists say. However — and it’s very important you grasp this — it’s also causing record-cold temperatures like the ones we’ve had for the past few winters. So if you sit in your car on a sunny day with the windows rolled up, the interior of the car will become very hot, but also very cold now and then. And you’ll get more snow.
In the car?
No, on the earth. You see, according to Al Gore, the record snowfalls we saw all over the northern hemisphere this winter were caused by global warming.
I don’t understand.
Not to worry; Al explained it to everyone in an editorial a few weeks back. Global warming is increasing the rate of evaporation from the oceans, you see, so there’s more moisture in the atmosphere, which means we’re getting more rain and more snow.
But I thought global warming was going to create more deserts.
That’s correct … more rain and snow, but also more deserts. You see, if you mix higher temperatures with more moisture, you get a desert, just like in a greenhouse.
I thought the purpose of a greenhouse is to grow more plants, like in a jungle.
No, no, no. The earth is a special kind of greenhouse. According to the IPCC, global warming is making the dry areas on earth drier, but also making the wet areas wetter … except in really wet areas like the Amazon rainforest, where global warming is causing the jungle to dry out.
Wait, let me get this straight: the dry areas are getting less rain because of global warming, and the wet areas are getting more rain because of global warming, except for the wet areas that aren’t getting enough rain because of global warming?
You’re catching on.
But at least we know it’s getting warmer, right?
That’s right. The temperature has been rising steadily, except for when it hasn’t. But those are just decadal variations.
What’s a decadal variation?
It’s what global-warming scientists call a long period of time when there’s no rise in temperature.
Decadal … so that would mean 10 years?
Yes. Except there was a decadal variation from 1945 to 1975, and the current decadal variation has lasted for 15 years now. See, if the temperature rises for 21 years, that’s a long-term trend. But if the temperature holds steady and then starts dropping over a period of 15 years, that’s a decadal variation.
But what if the temperature goes down again for, say, 20 or even 30 years? Wouldn’t that be a long-term trend?
Of course not. That would be two or three decadal variations strung together. Totally different thing.
This is getting kind of confusing.
No, it’s simple. Let me summarize: carbon dioxide is higher now than it’s ever been except for it when it was several times higher, and that’s bad because carbon dioxide traps heat and makes the planet warmer, except for when the temperature goes down anyway. Meanwhile, the rising temperatures are making wet areas wetter and dry areas drier, except for the wet areas that are becoming drier. Is it all clear now?
No. That doesn’t make any sense whatsoever.
Well, I’m afraid you might have a logical mind. It’s mostly a good thing, but it’s not going to help your academic career. Good luck with that paper.
Entries (RSS)