Trees Overview



Resource Library          Quick Facts           Tips and Troubleshooting

Along with producing the oxygen that we breathe and providing habitats for animals, healthy forests are also an important carbon sink-- meaning that they store carbon. Tree height is a primary indicator of how well an ecosystem can grow trees. NASA scientists study trees from space using satellites like ICESat-2, which measures forests using lasers. Your tree height and circumference measurements can help scientists understand how carbon moves through ecosystems.

Integrate GLOBE Trees into your programming by exploring the role of trees through a fun game of tag or using various tools and methods to measure tree height.

Trees Resource Library

Resource Library


Books, Videos and Presentations

Printables and Promotional Materials

Find activities to integrate into carts, demonstrations, classes and more.

Add books, videos and presentations to your program.

Promote your program with these resources and give visitors something to bring home.

Trees Quick Facts

Quick Facts

Why measure tree height? What do trees have to do with Earth's carbon cycle? Prepare for your program or develop a script using these common questions.

Trees Tips

Tips and Troubleshooting


Participants will be looking at their devices; be sure to choose a location with even ground and away from traffic and other hazards. If you must use a parking lot, try to block off an area for your program. Participants will also need to walk in a straight line to the base of the tree to complete their observation; check for exposed roots and dangerous plants, like poison ivy. Avoid trees with hairy vines growing up the trunk.


Plan out your route before the program, and check the day before in order to avoid surprises like downed trees. When choosing a location, keep time, safety considerations, ease of classification and diversity of land cover types in mind. When selecting a tree, try to find one that is straight, and that you can easily see the top. Look for isolated trees over 15 feet tall.

In some instances, you might need to present indoors. You can still demonstrate the app inside-- just don't send the observations to GLOBE. Bring handouts like the GLOBE Observer postcard so that visitors remember to check out the app on their own time.


Test your smart devices with the app before the program. Some devices do not have a gyroscope which is necessary for recording the angle that you are holding your phone at.

Presentation Tips

Determine the internet connectivity of your location. If you are providing devices, ensure that the app is downloaded and updated prior to the program. If participants will be using their own devices, ensure that they will have internet access or ask them to download the app prior to their arrival.

Sharing the app on a smartphone is fine for individual interactions, but you may wish to use a tablet with groups so that everyone can see what's on the screen. Remember that you will need to adjust the height of the observer in the app if sharing one device.

When participants are using the app, be sure that they are holding the device at the same height while measuring the top and bottom; raising or lowing their arms will lower the accuracy of the measurement. A stick or tripod can be used to keep the phone at the same height.

Trees Connections

Graphic shows a freshwater pond containing mosquito larvae, transitioning into a grassy area with rain falling transitioning into a dry desert with saguaro cactuses.

Trees are a type of land cover and they often rely on the precipitation carried by clouds, while also impacting the formation of clouds.

< Clouds      Land Cover >

Trees Featured Satellite

Animation of ICESat-2 taking measurements of the Earth using green lasers.

The Ice, Cloud, and Land Elevation Satellite-2, or ICESat-2, measures the height of a changing Earth, one laser pulse at a time, 10,000 laser pulses a second. Launched September 15, 2018, ICESat-2 carries a photon-counting laser altimeter that will allow scientists to measure the height of trees by comparing the elevation of the ground with the top of the forest.

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