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Seeing Green
Who Are NASA's Earth Explorers?

The elementary school student wondering how El Niño will affect tomorrow's weather. The scientist studying connections between ozone and climate change. And the farmer using satellite pictures to keep track of crops. All of these people are Earth Explorers -- they are all curious about the Earth system. This series will introduce you to NASA Earth Explorers, young and old, with many backgrounds and interests.

Imagine a pretty garden. Think about all the plants and flowers. Now picture the garden on top of a roof. Why would anyone put a garden up there? It's not as crazy as it sounds.

Jason stands in front of a statue that looks like a crab
Image above: Jason writes down temperatures in New York City. Credit: NASA GISS
A roof covered with plants is called a green roof. This kind of roof could be good for cities. Most cities heat up more than other areas. That's because cities have a lot of buildings. And they have a lot of roads and sidewalks. These surfaces absorb more heat than grass and trees. Green roofs may be a good way to cool cities.

NASA scientists want to learn as much as they can about green roofs. They want to know how much cooler they are than normal roofs. They want to know what other benefits they might provide. And they want to know if green roofs are worth their price. They can cost twice as much as a normal roof.

The scientists are getting help from students.

Jason is 16 years old. He's been all over New York City. It's a good city to test out green roofs. It has many buildings. And it has many roads and sidewalks. Jason's job has been to measure temperatures. He doesn't care so much about air temperature. What matters most are roofs and walls. Roads and sidewalks are also important. So are grass and leaves. Jason is careful with his work.

"I needed to have everything all correct so that nothing will go wrong," he said.

Jason gives his data to Adam Greenbaum. Adam is in college. He puts the data into a computer. The computer then makes predictions. It predicts how warm or cool different kinds of roofs will be. Adam likes what he's doing. He's always liked science. This is probably because his dad is a scientist.

"Ever since I was really little, he was explaining things to me," Adam said.

Stuart Gaffin is one of the scientists working on the project. He doesn't know yet if his research will show the value of green roofs. There is one study that shows that green roofs can be 50 degrees cooler than dark roofs. What makes green roofs so much cooler? For one, they are lighter in color. So they reflect more sun. Also, plants use nearby heat to turn water into gas. That also makes green roofs cooler.

Adam Greenbaum sitting at a computer
Image above: Adam Greenbaum puts data into a computer. Credit: NASA GISS
There may be other benefits to green roofs, too. They could make our air and water cleaner. And they may last longer than a normal roof.

How did Jason and Adam come to help with this study? They are part of a special summer program. It teams students with scientists. They work together on NASA projects. The students also do other things. They go to meetings and speeches. They present oral reports. And they visit science labs and museums.

Jason and Adam have to go back to school in the fall. But Stuart plans to use their work after they are gone. He still has a lot of questions to answer. He wants to know what kinds of plants work best on green roofs. And he wants to know how green roofs affect air inside of buildings.

It takes a lot of hard work to answer those kinds of questions. In fact, it takes a lot of hard work to become a scientist. But Adam says it's worth it. He says that in the end you get to do really neat stuff.

"There's something at the end that's worth getting to," he said.

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Dan Stillman, Institute for Global Environmental Strategies