Human Footprint Degrades Landscapes, Risks Sixth Mass Extinction
Human activity is degrading landscapes, driving species to extinction, worsening the effects of climate change, and already imperiling 3.2 billion people—two-fifths of humanity—according to a three-year, peer-reviewed study released last week by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.
The human footprint is “pushing the planet towards a sixth mass species extinction,” said assessment co-chair Robert Scholes. “Avoiding, reducing, and reversing this problem, and restoring degraded land, is an urgent priority to protect the biodiversity and ecosystem services vital to all life on Earth.”
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“Land degradation, biodiversity loss, and climate change are three different faces of the same central challenge: the increasingly dangerous impact of our choices on the health of our natural environment,” added IPBES Chair Sir Robert Watson. “We cannot afford to tackle any one of these three threats in isolation. They each deserve the highest policy priority and must be addressed together.”
Produced by 100 experts from 45 countries, and approved by 129 national governments, the report “says land loss and drought will displace at least 50 million people by 2050, and as many as 700 million over the coming four decades,” CBC reports. The Guardian says the degree of displacement will depend on “actions taken by governments to address climate change and the decline in soil quality,” adding that “worst-affected areas are likely to be the dry fringes of southern Iraq, Afghanistan, sub-Saharan Africa, and southern Asia.”
The report attributes the looming crisis to a “high-consumption lifestyle” and fast-rising populations in the developing world. It notes that the Earth has lost 87% of its wetlands areas since the start of the modern era, 54% since 1900.
Renewable freshwater per person has fallen 50% since the 1960s, 95% of North American tall grass prairies have been turned into “human-dominated landscapes”, coral reef coverage was down 90% by 2003, and “the galloping exploitation of the Amazon forest has seen 17% of the landscape turned over to settlement and agriculture,” CBC writes.
Overall, the IPBES warns that 71% of the world’s population now lives in areas where “the ability of ecosystems to support human societies” is threatened by biodiversity loss. “Less than a quarter of the planet remains untouched by human activity, but at current rates of expansion and exploitation, that figure will fall to less than 10% by 2050,” CBC notes.
“The growing sense of alarm was apparent last year when scientists warned fertile soil was being lost at the rate of 24 billion tonnes a year, largely due to unsustainable agricultural practices,” The Guardian writes. “The new assessment goes further by looking at vegetation loss, forest clearance, wetland drainage, grassland conversion, urban sprawl, and pollution, as well as how these changes affect human health, wealth, and happiness.”
Based on more than 3,000 scientific, government, Indigenous, and local knowledge sources, the authors calculate that land degradation “costs more than 10% of annual global GDP in lost ecosystem services such as carbon sequestration and agricultural productivity. They say it can raise the risks of flooding, landslides, and diseases such as Ebola and the Marburg virus,” the paper notes.
The loss of land and biodiversity also has geopolitical implications, The Guardian adds. “The authors cite evidence of a strong association between land degradation, migration, and instability. In dryland regions, years of extremely low rainfall have been associated with an up to 45% rise in violent conflict.”