API Tutorial: Hansen/UMD/Google Global Forest Change

 Global Change, 2000 - 2012
 Change in Riau, Indonesia, 2000 - 2012
Change in Paraguay, 2000 - 2012

Welcome to the Google Earth Engine tutorial for data related to the Hansen, Potapov, Moore, Hancher et al. paper on Global Forest Change published in Science magazine on November 15, 2013 and viewable on the Global Forest Change website. This tutorial provides examples of how to use Earth Engine's programming language to visualize the Global Forest Change data, how to compute forest change over time and other statistics within a region of interest, how to manipulate vector datasets to restrict analyses to specific areas of interest, and how to download both the data and results of analyses that you might perform.

Table of Contents
About Google Earth Engine

Earth Engine is a platform for planetary-scale environmental data analysis. It brings together over 40 years of historical and current global satellite imagery, and provides the tools and computational power necessary to analyze and mine its vast data warehouse. The data catalog, coupled with Google's computational infrastructure and geospatial analysis programming interface, provide the ability to perform large scale, complex analyses previously available to just a few institutions. Current applications include: detecting deforestation, classifying land cover and land cover change, estimating biomass and carbon, and mapping the world’s roadless areas. Google Earth Engine was a critical component in the creation of the Global Forest Change data set. For details, see the Google blog post about the study.


This tutorial is an introduction to using Earth Engine for advanced analysis. The tutorial assumes no programming background, although it does assume a willingness to learn some programming. The Earth Engine programming interface (also called the Earth Engine API)  supports two programming languages: JavaScript and Python. This tutorial will focus on the JavaScript version, starting with basic visualizations, and ending with complex operations.

Earth Engine experts, or programmers who just want to dive right in, should jump straight to the reference guide which summarizes all you need to know to view and analyze the Global Forest Change dataset, and lists all of the most significant scripts in the tutorial.

If you are primarily interested in viewing the Global Forest Change dataset and comparing it with other datasets, this Earth Engine Workspace should serve your needs.   

License and Attribution

Creative Commons License

The Global Forest Change data described in this tutorial is licensed under a Creative Commons Attribution 4.0 International Licesne.  You are free to copy and redistribute the material in any media or format, and to transform and build upon the material for any purpose, even commercially.  You must give appropriate credit, provide a link to the license, and indicate if changes were made.  Use the following credit when these data are displayed:

Source: Hansen/UMD/Google/USGS/NASA

Use the following credit when these data are cited: Hansen, M. C., P. V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S. V. Stehman, S. J. Goetz, T. R. Loveland, A. Kommareddy, A. Egorov, L. Chini, C. O. Justice, and J. R. G. Townshend. 2013. “High-Resolution Global Maps of 21st-Century Forest Cover Change.” Science 342 (15 November): 850–53. Data available on-line from:http://earthenginepartners.appspot.com/science-2013-global-forest.

Getting Started

Access to the advanced Earth Engine tools is free, but restricted to those who have a good use for the platform and agree to our trusted tester agreement.  To get access, please fill out our Earth Engine signup form.   Those granted access will receive an email from trustedtester@google.com within a few business days with further instructions. 

Once you have been granted access, the next step is to tour the Earth Engine Playground, our developer environment for running Earth Engine API code.  Let's get started!