Five maps that reveal the world’s remaining wilderness
The world’s remaining wilderness. Dark blue = terrestrial. Light blue = marine. Credit: Modified with permission from Protect the last of the wild, Watson et al, Nature (2018)
There aren’t many corners of the world left untouched by humanity. Recent research has highlighted that just 23% of the planet’s land surface (excluding Antarctica) and 13% of the ocean can now be classified as wilderness, representing nearly a 10% decline over the last 20 years. And more than 70% of what wilderness remains is contained within just five countries.
Researchers from the US and Australia recently produced a global map to illustrate this decline, made by combining data on things such as population density, night-time lights and types of vegetation. The problem with such an approach is that the question of where wilderness begins and ends is not as simple as it may first seem.
The data used to map wilderness is often collected in different ways for different parts of the world. For example, some datasets map roads all the way down to farm and forest tracks, while others may only record primary road networks. The definition of how far land has to be from these roads to be classified as wilderness can also vary. Meanwhile, knitting all this data into a single map often leads to compromises that reduce its usefulness, such as not including any blocks of wilderness below a certain size.
So while global maps are useful for drawing attention to the attrition of wilderness areas, only the greater detail of national and local maps can really help us understand and respond to the threats that face our remaining wild areas.
Scotland is perhaps the country with the most detailed wilderness mapping in the world today. It has been mapped at global, continental, national, regional and local scales, each one showing progressively more detail, and higher levels of accuracy and reliability. The Scottish government has been able to use these maps to define what should count as protected “wild land” in the most effective way.
Early maps showed most wilderness was in the uninhabited highlands and suggested there were almost no wild areas around the main cities of Glasgow and Edinburgh. But by zooming in and reducing the size threshold of what counted as wilderness, the government identified smaller areas of wild land nearer to cities that are just as important for recreation, and landscape, habitat and ecosystem conservation.
China is following suit with a similar approach and using national level mapping to define wilderness areas and help develop a new national park system. The country can be neatly divided in two as highlighted by what’s known as the “Hu Line”, a simple straight line that connects Ai-hui in the north-east to Teng-Chong in the south-west. East of this line, the country is densely populated and intensively farmed. To the west, human population is sparse and the land remains largely wild.
Chinese geographers are now developing methods to cope with this marked polarity in the distribution of the country’s wilderness. As with Scotland, they need to identify those smaller pockets of wild ecosystems that remain within the otherwise fragmented and developed landscapes of the east.