World Wildlife Fund scientists, working with scientists from NASA and other institutions, have produced a unique map of human consumption of the Earth’s biological resources — everything from wood and paper to meat and grains. The research appears in today’s Nature.
"This research illustrates the uneven footprint of human consumption," said Taylor Ricketts, director of conservation science at WWF and an author of the study. "One of our key findings is that many regions are already consuming far beyond what their local area could possibly produce. These areas are being subsidized by imports from other parts of the world; they are literally on life support."
The researchers based their analyses on the concept of "net primary production," the process by which plants use sunlight to "fix" carbon from the air. These plants then fuel the world’s complex food webs. Net primary production therefore represents the primary energy source for the world’s ecosystems and for the human supply of food, construction materials, and other products.
The study found that humans, which represent roughly half of 1 percent of the total biomass on Earth, appropriate about 20 percent of this primary resource annually. In addition, consumption among regions varies widely. Western Europe and South Central Asia consume more than 70 percent of what their regions produce, while in South America just 6 percent is consumed.
"The study also allows a glimpse into future consumption," continued Ricketts. "If developing nations continue to increase their consumption to match industrialized nations, worldwide consumption would increase 75 percent and the list of regions that consume beyond local production would get a lot longer."
Fortunately, the study also highlights ways in which efficient technologies can mitigate consumption growth. For example, 1 ton of milled lumber requires an average of 2 tons of trees in developing countries, but only 1.3 tons in developed nations.
"The clear message for conservationists is that we need to find paths toward economic development that require less of the world’s biological resources if we are to develop in a sustainable way."
"The missing part of the story so far is trade, and that’s what we plan to examine next," said Colby Loucks, senior conservation specialist at WWF.
In the modern age of globalization, people clearly no longer consume only the resources grown locally.
"Our map shows where products are consumed, not where they are harvested from the ecosystem." Loucks continued, "Indonesia, for instance, has one of the highest rates of deforestation in the world, but it exports most of its lumber, so the consumption of that resource is mapped elsewhere." Tracing those trading links will complete the picture of global consumption patterns begun with this study.
