"Paru Paru Dunia" means "lungs of the Earth" in Indonesian. This expression is used sometimes to refer to the forests of Indonesia. This is because of the important role trees play in filtering the air. Trees and other plants are crucial for maintaining balance in the atmosphere because they take in carbon dioxide and release oxygen, and people need oxygen to live. The world is interested in the fate of the forests of Indonesia in part because of this, because this country has among the largest areas of tropical rain forest on the planet. But what exactly is a rain forest? They are areas near the equator (1) that receive very high amounts of rain throughout the year (though there are often seasonal variations). These places receive lots of rain because they are near the inter-tropical convergence zone. That's a pretty big expression, but let's see if we can figure out what it means. First, "inter-". This usually means "between" or "among", and that's what it means here. From earlier posts you should already know what "tropical" means. So we are halfway there...the first part means "between the tropics". Next "convergence". What does "converge" mean? When two things converge, what do they do? That's right, they come together. And the last word is easy. So the ITCZ is a place between the tropics where something comes together. But what comes together? The answer is simple: air. In the atmosphere the air is constantly moving. You've certainly experienced this in Hawai'i...every time you feel the wind blowing you are feeling the air move in the atmosphere. Because of the relationship between the Earth and the Sun, the places near the equator are always the closest places on the planet to the Sun (2). And what do we know about the Sun? That's right, it's hot. So it makes sense that the hottest places on the planet will be those closest to the Sun. And when air heats up, it rises. You've probably experienced this before if you've ever been in your grandparents' attic. It's always hotter in the attic than it is in the house because warm air rises. That's exactly what happens at the equator...the air rises because it is warm. As the air rises, more air has to come in to fill the space left by the rising air. This new air comes from north and south of the equator; thus it converges at the equator. There's one last thing you need to know about this. As air rises, it cools down. You've probably experienced this if you've ever gone on any of the great trails that climb up the Wainae or Ko'olau mountains on O'ahu. Or if you've ever been up on Haleakala or Mauna Kea. It's so cold up there it even snows sometimes! So as the air rises and cools down, it makes clouds. And we all know what clouds mean...RAIN! So you can see that this is a kind of cycle that is always at work, and the result of it is very consistent rainfall. I've included a cross-section diagram of how this works to the right. Geographers call this pattern "the Hadley Cell", but you don't have to remember that unless you are in the 3rd grade or higher :).
Now look at the diagram. Notice that this cycle is right at the equator. Next have a look at the rain forest map I included above. Where are most of the rain forests? Now you can understand why there is so much rain in these places. Rain is very good for plants, so the forests that grow in these places are very rich. So what's the problem? Well, the rain forests of the world are disappearing at an alarming rate. They are being cut down and burned faster than they can grow back! Have a look at the map of Borneo (3) I've included. Forest cover is represented in green on this map.
As you can see, the past 60 years has seen a dramatic loss. The same is true with other important forest "hot spots" in Indonesia, including Sumatra (where I am; see the map) and Papua. Where are the forests going? Well you may recall from a previous post that some people cut down the trees to sell, while others cut them down to grow crops to eat and sell. But there are other pressures as well. In many cases, places that are rich in forests are also rich in valuable minerals. Thus mining is another activity that causes forests to be cut down. All of these activities are good for some people in the short term, but they are bad for all the people in the long term. So why don't we just stop all the logging and mining? This is a very tough question, but part of the answer is because most of the countries where rain forests are found are relatively poor. One of the ways these nations make money is to sell raw materials, resources that are taken from the earth and later made into other things. Everything you wear, own, and want is made from raw materials of some kind, and they have to come from some place. In addition, people that are poor do not have the luxury of thinking years into the future, because they are worried about having enough to eat for dinner. And because of the importance of the inter-tropical convergence zone, these forests can't just grow anywhere. So you can see that this is a pretty difficult problem to solve; it is a uniquely geographical problem. As one local farmer said, "TNKS terkenal sebagai paru-paru dunia, tapi pada kesempatan paru-paru masyarakat yang ada desekitar kawasan TNKS terasa kempes dan sesak. Bagaimana TNKS menyikapi hal ini? Apa kontribusi yang diberikan TNKS untuk masyarakat?" Loosely translated, this means "Kerinci Seblat National park is known as the lungs of the world, but as for the lungs of the people living around the park, we feel deflated. How does the national park feel about that? What benefit does the park have for people living around it?"
Think about that for a while. How would you go about solving it? While you're thinking about it I'm going to get some sleep. You can email me some of your ideas!
1) Can you find the equator on a map or globe?
2) You might be able to make a simple model of the Earth-Sun relationship with a lightbulb and a globe. If you have a globe, you will notice that it is tilted (at an angle of about 23.5 degrees). This is because, in relation to the Sun, the Earth is tilted in space! This is very important for the changing seasons. What else can you notice about the Earth-Sun relationship?
3) Borneo is a large island in the Indonesian archipelago (chain of islands...Hawai'i is an archipelago). Most of Borneo is part of Indonesia, but part of it is part of the nation of Malaysia, and there is another small country called Brunei on Borneo as well.