Earth is a comfortable place for living things. It's just the right temperatures for plants and animals–including humans–to thrive.

對所有生物來說，地球是一個適合居住的地方。因為地球的溫度剛好能讓植物、動物，包括人類茁壯成長。

Why is Earth so special?

為什麼地球這麼特別？

Well, one reason is: the greenhouse effect.

主要原因是地球有溫室效應。

A greenhouse is a building with glass walls and a glass roof.

溫室指的是一個由玻璃牆和玻璃屋頂組成的建築物。

The clear glass allows sunlight to shine into the greenhouse, while also trapping the Sun's heat inside.

陽光透過清澈的玻璃照進溫室，而密閉的玻璃牆把太陽的熱能鎖在溫室內。

This is how a greenhouse keeps plants warm, even at night and in the winter.

在這樣的原理下，溫室內得以在夜晚與冬天保持恆溫，延續植物的生命。

The greenhouse effect keeps Earth warm in pretty much the same way.

地球之所以能常年保持溫暖，也是溫室效應所致。

Earth isn't surrounded by glass, but it is surrounded by a jacket of gases called the atmosphere.

不過地球外圍沒有玻璃罩，籠罩在地球四周的是一個叫大氣層的氣體。

In the daytime, the Sun shines through the atmosphere warming Earth's surface.

白天時，陽光穿過大氣層溫暖了地球表面。

After the Sun goes down, Earth's surface cools. This releases heat back into the air. But some of that heat is trapped by the gases in the atmosphere.

太陽下山後，地球表面會降溫，把熱能釋放回空氣中並散逸，但有一些熱能會被大氣層的氣體所吸收。

These heat-trapping gases are called greenhouse gases. Carbon dioxide, water vapor and methane are all examples of greenhouse gases.

這種積蓄熱能的氣體就叫溫室氣體。二氧化碳、水蒸氣、甲烷都是溫室氣體。

Earth needs a balance of greenhouse gases to maintain just the right temperature for living things.

地球需要適量的溫室氣體來為生物提供剛好的生存溫度。

But some human activities are changing Earth's natural greenhouse effect.

但一些人類活動卻對地球天然的溫室效應造成了影響。

For example, burning fossil fuels, like coal and oil, releases more carbon dioxide into our atmosphere.

例如像煤和石油等化石燃料的燃燒，釋放了更多的二氧化碳到大氣層。

These extra greenhouse gases can cause the atmosphere to trap more and more heat, leading to a warmer Earth.

這些額外的溫室氣體會導致大氣層積蓄越來越多的熱能，導致地球越來越溫暖。

NASA satellites are constantly measuring the gases in our atmosphere from space.

美國太空總署持續透過衛星在外太空監測大氣層氣體的濃度。

They have observed increases in the amount of carbon dioxide and other greenhouse gases.

並發現二氧化碳和其他溫室氣體的濃度有增加的跡象。

The information from NASA satellites can help scientists figure out where greenhouse gases are coming from and how they are ending up in our atmosphere.

美國太空總署從衛星觀察到的資訊可以幫助科學家們找出溫室氣體的來源和它們在大氣層發生什麼事。

This information will help us better understand the impact that greenhouse gases have on our climate.

這些資訊除了可以幫助我們更了解溫室氣體對氣候造成的影響。

And help us better understand this very special greenhouse that we call home.

也有助於我們更了解這個我們稱之為「家」的特殊溫室。

Find out more about our Earth at NASA Climate Kids!

想了解更多關於地球的事，瀏覽美國太空總署氣候兒童網站！