Earth | Global Forest Change 2000-2012

An important body of research mapped the changes in forests of the Earth. The work showed areas of forest loss and gain over the entire globe as mapped by Landsat satellites between 2000-2012. Each pixel of a Landsat image covers 30×30 meters, about the size of a baseball diamond. That makes the level of resolution quite good. The researchers analyzed 143 billion pixels in 654,000 Landsat images to compile the maps. Scientists from the University of Maryland, Google, the State University of New York, Woods Hole Research Center, the U.S. Geological Survey (USGS) and South Dakota State University were part of the research team. Abstract in the November 15 issue of the journal Science.

Deforestation is a growing and very significant problem world wide. The biomass in our forests is huge. They contribute enormously to the processing of carbon dioxide to oxygen. Previous country to country comparisons have been difficult. Some countries allow limited or no access to certain regions. Countries have different criteria when asked to self-report. This Landsat analysis uses a uniformly applied set of standards over a long time period. Here is an example of a map showing loss and gain in a region of Sumatra. Red indicates cleared forest and blue is new growth. Purple shows areas of trees both cut down and re-grown. Green is forest cover that has not been disturbed. Indonesia’s deforestation rate has doubled from levels in 2000-2003.

Here is an example from the southeastern United States near Jacksonville, Florida. In it we see a fine patchwork of purple. Landowners harvest trees and quickly replant. Trees are treated as a crop. About 30% of the forests were regrown or lost during this 12 yr. period. That is an intensive use of the resource. It explains the purple color showing both loss and gain over the period.

Public Access to the Data

You may be wondering if you can see the region where you live in this Landsat data. The answer is yes. There is an excellent online tool constructed with the cooperation of Google Earth which compiles the global data into a form that allows you to search for a location and zoom into your house and neighborhood. I added four arrows to the home page of the tool Global Forest Change from the U. of Maryland Dept. of Geographical Sciences. They are part of a navigation tutorial I will present below. Go ahead and click on the GFC link in the previous sentence to open this new window or tab in your browser. Then, come back here for some simple instructions.

In the lower left is the zoom tool. Upper left shows a search box for locations. Upper right points to Map and is where you can change to Satellite view later. At the right is a slider to make the overlay of the forest map be less or more transparent. Here is what I want you to do in your new window or tab.

• In the upper left search box type Alto Paraíso – Rondônia, Brazil. Hit return to see a bigger version of this image.

• Move the transparency slider all the way left. You are in the right place. But the map doesn’t show much is there.

• Change the Map in the upper right to Satellite. Now you can see the actual surface details.

• Move the slider back and forth to notice the locations of the red deforested areas. You can zoom in for greater detail. Notice the farms or ranches. These rectangular plots are areas cleared of forest mainly for  agribusiness. Bolivia, Paraguay and Argentina are under intensive pressure from agroindustrial development. Paraguay’s Chaco woodlands within the western half of the country are experiencing rapid deforestation in the development of cattle ranches. The result is the highest rate of deforestation in the world. Brazil has reduced their rate of deforestation. But, remote areas like this are hard to manage.

Example Locations

Explore some preset example locations with the drop down menu at the lower right of the window. One I suggest is the first about the Alabama tornado. Once you select it, then below it click zoom to area. Don’t forget to move the transparency slider and change the zoom.

Check Your Neighborhood

Or, search for a location you remember hearing about in the news that had forest fires a few years ago. The fires this year won’t show on this map.


Landsat was first launched 41 years ago. Several others have been added over the years. The most recent is Landsat 8 launched in February 2013. Image analysis has improved as computers have become more powerful. The USGS made the data freely available on the Internet in 2008. That has allowed research projects such as this one to be done adding to our awareness of Earth’s systems and the issue of deforestation in particular.


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19 thoughts on “Earth | Global Forest Change 2000-2012

    • Visualizations can be such an important part in presentation of data. Tools like this use a common interface that most people have used. When I first saw it and the key elements of a Google map window, I dived right in and started playing around to learn more. It is so important to make the data publicly available.

      Thank you for your comment.

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  1. Very nice explanations of what is going on worldwide. Forests provide lots of ecosystem services (benefits to human well-being). There is lots of data available to show the negative trend; now is the time to bend the trend in a positive direction.

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    • I couldn’t agree more. Sadly, searching the map shows much more red than blue. The southeast US has some of the highest amount of blue.

      Thanks for stopping in this morning.

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      • So true, it is sad to see the destruction on a daily basis around me. People move to a neighborhood Forest Glen or something because they want their children to play in the woods and then chop the woods in their backyard because they cause ‘such a mess’. I am still baffled by it.

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      • I know what you mean. About 10 yrs ago, a wooded acreage directly behind us was being prepared by the developer for housing. Chain saws and heavy equipment ran almost every day for 3 months as they destroyed the trees and graded the road and lots. It was such an awful thing to hear and see.

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      • It sounds to me like crying trees. Just awful. Time to plant more stuff in our own backyard… I just planted two saw palmettos a month ago. To see plants and trees grow over the years is a happy sight.

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  2. I’ve seen plenty of nature disappear in the 15 years I’ve been interested in native plants in central Texas, but what gets developed here is on a small scale compared to places like Brazil and Indonesia.

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    • I agree. We can see the same near us. It’s a very powerful tool. I hope it can be used for some good to help protect our forests.

      Thank you for stopping by.

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  3. Fascinating set of data. Several things jump out from these maps, not the least of which is how little of the earth’s land surface is actually forest. They define trees as over 5m – where I live (Pacific NW) that’s considered a shrub as much as a tree. But in the Yucatan, I see their very short trees are considered forest – makes sense, since they form a canopy (although you don’t have to climb many steps up one of the pyramids there to see over the top, for miles and miles. I notice there that almost all the recent logging is along the roads – even without the features overlay you can identify the roads.

    One aspect the satellite images can’t extract is how old the forest is. Looking at my county, most of the land is mapped as forest, even though on the ground it’s virtually all just a few decades old. The quality of the forest habitat can not be judged by the green. To me this means there’s a risk of complacency in agencies that use this data – we shouldn’t be equating forest cover with ecological health.

    Cool site, thanks for sharing. And your directions on how to use it is a dead giveaway you used to be a high school teacher 😉 Teachers give better directions than anyone, in my experience 🙂

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    • Hi. Nice to see your thoughtful comments.

      When I first browsed the maps, I headed for the middle of S. America knowing there were problems there. I started seeing these fine grid-like patterns. My first thought was they were new streets for expansion of cities. I zoomed in and made the overlay transparent. There were no big cities there. That’s when I discovered the farms and plots of land that were cleared. Amazing detail.

      I couldn’t agree more that there needs to be some truth-on-the-ground reporting to cross-check the satellite views. I think some level of info can be had about the health of a forest canopy by the spectrum of light sensed. Plus the intensity of a color might tell the density of a stand.

      Your teacher comment made me chuckle. I liked that one. Proud to be a member of that group. 🙂

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