2016-09-08. We’ve destroyed one-tenth of Earth’s wilderness in just 2 decades.

posted Sep 13, 2016, 2:59 PM by Alan Gould
By Elizabeth Pennisi, Science. For GSS Losing Biodiversity chapter 8 and Ecosystem Change chapter 6. Excerpt: When most people think about conservation, they probably imagine saving the panda, or some other threatened creature, or maybe protecting whatever remains of its habitat. But James Watson thinks we’re missing the big picture. Large swaths of wilderness also really need our help, he and his colleagues report today. They have compared the extent of Earth’s wilderness areas in 1993 and 2009, documenting almost a 30% loss in South America and a 10% loss globally.  Similar estimates in the past have focused on deforestation, but the new study looks at the disappearance of a broader range of wild landscapes. ...Such unspoiled regions, scientists argue, are also critical for allowing the planet to cope with climate change. ...Watson, a conservation biogeographer at the Wildlife Conservation Society based at the University of Queensland, St. Lucia, in Brisbane, Australia, and his colleagues earlier determined the extent of the “human footprint” on Earth by incorporating maps and data on crop lands, pastures, night lighting, railways, roadways, navigable waterways, population densities, and “built” environments, which included urban areas and other settlements. For most of these threats to wilderness, they had satellite and other data from the early 1990s and for the late 2000s. All but two of these pressures have increased in that time, Watson and his colleagues reported in a study last month in Nature Communications. (Roadways and waterways haven’t expanded noticeably.) Wilderness is defined as pristine landscapes mostly free of human disturbances, including roads.  ...By 2009, about 23% of Earth’s land remained as wilderness—about 30.1 million square kilometers spread mostly across North America, North Asia, North Africa, and Australia, they conclude today in Current Biology. That’s 3.3 million square kilometers less than in 1993, .... South America has lost almost 30% of its wilderness in that time and Africa has lost 14%....  http://www.sciencemag.org/news/2016/09/we-ve-destroyed-one-tenth-earth-s-wilderness-just-2-decades