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The Earth is getting warmer. This occurrence is officially called global warming, and it could cause some pretty important changes in our lives. The Earth has warmed up by one degree over the past 100 years, and while that might not seem like a lot, this change could have a big impact on our climate. Climate refers to the long-term trends of a region's weather events. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans.
According to the Environmental Protection Agency, global mean surface temperatures have increased 0.5–1.0°F since the late 19th century. The 20th century's warmest years all occurred in the last 15 years of the century. Global temperatures in 1998 were the warmest since reliable measurements began, and seven of the ten warmest years occurred in the 1990s.
But why is the Earth getting warmer? Scientists aren't exactly sure. It might be getting warmer on its own. But there are some scientists who believe that humans are doing things to make the Earth warmer. It goes like this:
When sunlight enters the Earth's atmosphere, it passes through a shield of gasses such as carbon dioxide and methane. As the sunlight reaches the Earth's surface, land and water absorb its energy and then send it back into the atmosphere. Some of the energy goes back into space, but much of it remains trapped in the atmosphere by these gasses, causing our world to heat up. Because these gasses keep things warm, they are called greenhouse gasses. The Greenhouse Effect is a natural process and has kept the Earth's temperature about 60 degrees Fahrenheit warmer than it would otherwise have been. Without it, it would be too cold on Earth to live.
Although greenhouse gasses occur naturally, humans produce additional amounts of these gasses by driving cars, watching TV, and even throwing out the trash. Some scientists believe that as additional gasses enter the atmosphere, the gasses will trap more of the sun's energy, producing a greater warming effect.
And, if the Earth gets any warmer, it could mean trouble for humans, plants, and animals. While scientists are not sure exactly what will happen, they predict that higher global temperatures could lead to human health problems such as heat-related diseases, changes in habitats to which plants and animals can't adapt, and the melting of glaciers. Melting glaciers could lead to rising sea levels, which could, in turn, change ocean ecosystems and cause coastal flooding.
Just think, by planting a tree, turning off a light, recycling your cans, or riding your bicycle, you could help save the planet!
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