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Global warming is a puzzle we need to solve.
Can we figure it out before it’s too late? Scientists know that temperatures on Earth are rising. But how much of that is global warming, and how much comes from natural changes? There’s no way to know for sure, and scientists have different ideas.
1875
2015
▲ The Rhône glacier (above) is in Switzerland. In 1875, it was an awesome sight. Today, it is much smaller, sitting halfway up the mountain. Over the past century and a half, glaciers have shrunk. However, data also show that some glaciers, like those in Scandinavia, are growing.
◀ Many scientists think global warming could affect the weather. It might cause some freaky weather, such as huge snowstorms.
The Greenhouse Effect
▲ What is the “greenhouse effect”? It happens naturally, when gases in the atmosphere trap some of the sun’s heat. If they didn’t, Earth would be too cold. The sun’s energy would just bounce back into space. But for the past century or so, people have put more greenhouse gases, like carbon dioxide, into the air. The extra gases could hold in too much heat. That could make parts of our planet too hot for life.
▲ A greenhouse holds in heat so plants can grow.
▲ This line graph shows how much carbon dioxide (CO2) is in Earth’s atmosphere. CO2 has been rising for a long time. It has gone up more quickly in recent years. Earth’s average temperature has risen at the same time. We measure CO2 in parts per million (ppm). The CO2 level is now more than 400 ppm. That means there are more than 400 units of CO2 in every 1 million units of air. That may not sound like a lot. Even so, it can make a big difference in Earth’s temperature!
Causes
▲ The main fossil fuels are coal, oil, and gas. Burning them creates carbon dioxide. The U.S. puts a lot of greenhouse gases in the air. Per person, it is one of the world’s biggest creators of these gases. But poorer countries are burning more fuel, too. That’s because their people are living better.
▲ Plants soak up the greenhouse gas carbon dioxide. Earth loses trees and other plants when forests are destroyed. Sometimes people burn land to clear it for farming. The fires make extra carbon dioxide. They also put methane and other gases into the air.
Possible Results
▲ The weather might get rougher due to global warming. Rainstorms could get stronger, bringing more floods and mudslides. This photo was taken after a mudslide in Italy. Also, the driest parts of the Earth could have even worse droughts. Higher temperatures would melt icecaps so much that sea levels would rise.
▲ The melting polar icecaps could make the oceans rise. That would be bad for coastal areas such as Florida. You can see that in the green areas on this image. However, it could take centuries for these changes to happen.
Think Piece!
Most scientists say we can slow down global warming. They say we should use less fossil fuel and find other kinds of energy. They can’t say exactly what global warming will do. They can’t tell us when it might happen. What would you give up to stop a global warming disaster? Would it matter if the disaster might not happen in your lifetime? Would you bike, not drive, to the mall? Use a push lawn mower instead of a motor-driven one?
