Community Trees Challenge 2021 - Overview

2021 Community Trees Challenge: Science is Better Together

15 April 2021 to 15 May 2021Trees Challenge logo

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Celebrate trees by joining the GLOBE citizen science community in the 2021 Community Trees Challenge, where Science is Better Together!


Who can participate: Everyone! (students and teachers at all grade levels, informal educators, and the public in GLOBE countries.) While getting out and taking observations might not be possible for everyone, this challenge provides multiple ways to participate and learn all about trees.

How to participate: During the Community Trees Challenge, The GLOBE Program is asking citizen scientists to observe, learn, engage, and create as they track their progress on the Trees Challenge activity tracker. You can choose the best journey for your interests or try to complete all the activities. Work together as a family, as a group of friends, or independently.

By completing these activities, you will improve your science observation skills, enrich your understanding of trees as part of our landscape, learn why NASA studies trees, be a part of a NASA-sponsored citizen science project, as well as join a citizen science community. Your observations of tree height contribute to a global database that is free and open so that anyone - scientists, students, communities, and citizen scientists - can conduct research.

Read the news story about the launch of the challenge, "You Better Beleaf it: NASA GLOBE Program to Host 2021 Trees Community Challenge."


The 2021 Community Trees Challenge has concluded. Read a summary of the challenge, and download a customizable certificate (PDF) to celebrate your participation. Print or share on social media, and thanks for joining in!

Image of Community Trees Challenge certificate


Community Trees Challenge 2021 - Participation Header

Choose your Participation Options:

Asset Publisher

Community Trees Challenge Activity Tracker

The Community Trees Challenge activity tracker will help you keep a log of how you participate in the challenge. See the list below for more details about each of the options on the page.

Full color version (PDF)

Black and white version for easier printing (PDF)

Trees Challenge 2021 - Translated Trackers

Thanks to our friends at the Los Angeles Public Library, we are pleased to also be able to offer the Community Trees Challenge activity tracker (full color version) in the following languages in addition to English:

հայերեն (Armenian),   中文 (Chinese),   日本語 (Japanese),   한국어 (Korean),   فارسی (Persian),   русский (Russian),   español (Spanish)

Community Trees Challenge 2021 - Activities

Observe trees:

Always follow guidelines from your local officials, and only participate in GLOBE activities or use the GLOBE Observer app if it is safe to do so.

Composite of observe activities, from left: the GLOBE Observer app, the paper clinometer activity sheet, the cover of a science journal, and an image of a landscape with trees.


Learn about trees:

Composite of learn activities, from left: pile of books, screenshots of videos, images of the GLOBE Visualization System, and the Trees Science webpage


Create with trees:

Composite of create activities, from left: art made with leaves, a map of a garden with trees, a tree poem, and a drawing of a tree cookie


Engage about trees:

As you complete activities or take observations, share your results with us through social media using #TreesChallenge new window or by tagging the GLOBE Program. 

  • Find a special tree and share what makes it special using #TreesChallenge. You can read about some examples of special trees in the blog post "What in the World are Moon Trees?"
  • Ask an expert a question about trees. For example, talk to a tree scientist or arborist, or visit a nearby garden center or nursery and ask questions about trees local to your area. You can also join us on Thursday, May 6th at 2:00 pm EDT/18:00 UTC for a Reddit "Ask Me Anything" event  on the r/AskScience new window channel, cross-posted to r/NASA new window . 
  • Make a short video about why trees are important and share it using #TreesChallenge.
  • Follow GLOBE on social media:

Facebook logo

Twitter logo

Instagram logo

YouTube logo


Composite of engage images: person on phone, asking an expert, a special tree, another person on a phone, the GLOBE Twitter page.


Looking for even more activities to try? Check out the Trees Resource Library, or visit the Trees Family Guide!