We humans have left our mark on the entire planet; not a single ecosystem remains completely untouched. But some landscapes have been affected less than others. And the extent to which the earth can provide habitats for plants and animals, sequester atmospheric carbon and regulate the flow of freshwater depends on the vastness of the least affected regions. These tracts, where human influence is still too weak to easily detect by satellite, are prime targets for conservation. Using satellite imagery, a group of researchers mapped the global decline between 2000 and 2013 of such “intact forest landscapes” (IFLs), defined as forested or naturally treeless ecosystems of 500 square kilometers or more. Around half of the area of the world's IFLs are in the tropics, and a third can be found in the boreal forests of North America and Eurasia. Logging, agriculture, mining and wildfires contributed to the drop, as reported in January in Science Advances.
The bright side? Landscapes under formal protection, such as national parks, were more likely to remain intact.
By the Numbers
square kilometers Global extent of IFLs in 2000, a total area equivalent to a third of the surface of the moon.
Nearly 1 million
square kilometers Approximate area of IFLs lost between 2000 and 2013, about the size of Egypt.
Number of countries that were home to at least one IFL in 2000.
Number of countries that will be completely devoid of IFLs in 60 years if losses continue at the current rate.