Wind erosion causes topsoil loss on over-used or improperly managed farmland, leading to widescale land damage around the world.
Photograph by Robb Kendrick, National Geographic Creative
Photograph by Robb Kendrick, National Geographic Creative
MEDELLIN, COLOMBIAMore
than 75 percent of Earth’s land areas are substantially degraded,
undermining the well-being of 3.2 billion people, according to the
world’s first comprehensive, evidence-based assessment. These lands that
have either become deserts, are polluted, or have been deforested and converted to agricultural production are also the main causes of species extinctions.
If this trend continues, 95 percent of the Earth’s land areas could
become degraded by 2050. That would potentially force hundreds of
millions of people to migrate, as food production collapses in many
places, the report warns. (Learn more about biodiversity under threat.)
“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,” said Sir Robert Watson, chair of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), which produced the report (launched Monday in Medellin, Colombia).
IPBES is the "IPCC for biodiversity"—a scientific assessment of the
status of non-human life that makes up the Earth’s life-support system.
The land degradation assessment took three years and more than 100
leading experts from 45 countries.
Would You Stay if Your Home Became a Desert?
Rapid expansion and unsustainable management of croplands and grazing
lands is the main driver of land degradation, causing significant loss
of biodiversity and impacting food security, water purification, the
provision of energy, and other contributions of nature essential to
people. This has reached “critical levels” in many parts of the world,
Watson said in an interview.
Underlying Causes
Wetlands have been hit hardest, with 87 percent lost globally in the
last 300 years. Some 54 percent have been lost since 1900. Wetlands
continue to be destroyed in Southeast Asia and the Congo region of
Africa, mainly to plant oil palm.
Underlying drivers of land degradation, says the report, are the
high-consumption lifestyles in the most developed economies, combined
with rising consumption in developing and emerging economies. High and
rising per capita consumption, amplified by continued population growth
in many parts of the world, are driving unsustainable levels of
agricultural expansion, natural resource and mineral extraction, and
urbanization.
“We’ve know about this for over 20 years but it is only getting
worse,” said Luca Montanarella, a soil scientist from Italy and co-chair
of the assessment.
Land degradation is rarely considered an urgent issue by most governments, even though many have signed an international agreement
to reach land degradation neutrality by 2030. “We need to find a stable
balance between our lifestyle and our impacts on nature,” Montanarella
said in an interview in Medellin.
Ending land degradation and restoring degraded land would get
humanity one third of the way to keeping global warming below 2°C, the
target climate scientists say we need to avoid the most devastating
impacts. Deforestation alone accounts for 10 percent of all
human-induced emissions.
Solutions Abound
For developing regions like parts of Asia and Africa, the cost of
inaction in the face of land degradation is at least three times higher
than the cost of action. And the benefits of restoration are 10 times
higher than the costs, the report found.
Ending production subsidies in agriculture, fisheries, energy, and
other sectors would go a long way to reducing pressure on nature.
Roughly 25 percent of Africa has shifted out of cattle and sheep
production simply because it has become too dry and unproductive to be
profitable, said Robert Scholes, a South African ecologist and co-chair
of the assessment.
“These lands are reverting back to wildlife, which are better adapted
to those conditions,” Scholes said. “The same things is happening in
Australia.”
There are many proven approaches to reversing these trends, including
urban planning, replanting with native species, green infrastructure
development, remediation of contaminated and sealed soils (e.g. under
asphalt), wastewater treatment, and river channel restoration.
Land needs to be managed at a landscape scale, where the needs of
agriculture, industry, and urban areas can be balanced in a holistic
way, Scholes said.
Better, more open-access information on the impacts of traded
commodities is also needed, he adds. Many rich countries “offshore”
their environmental impacts by importing huge quantities of food,
resources, and products from other countries. The European Union imports
30 to 40 percent of its food, for example.
“Through this report, the global community of experts has delivered a
frank and urgent warning, with clear options to address dire
environmental damage,” said Watson.
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