A new model shows which areas of Earth will likely be hit the hardest by the changes caused by human activity, also revealing possible solutions.
In a similar fashion, maps of coral reefs, mangroves, seagrasses, and salt marshes that can protect coastal erosion and storm surges were overlaid with maps of where people live on coasts.
Wild pollinators need natural habitat to survive, so maps of where food crops are grown were overlaid with existing areas of natural habitat.
The model then mapped what our societal needs are in terms of total nitrogen runoff, coastal risk, and pollination-dependent crop production. That was compared to where nature is currently providing such services to reveal current gaps in what humanity needs and what nature is providing.
Researchers then looked at three different future scenarios involving land use, climate, and population change out to 2050, according to an analysis by Carbon Brief. Those are standardized scenarios that incorporate changes in society, demographics, and economics.
The study paints a “deeply worrying picture of the societal burdens of losing nature,” writes Patricia Balvanera, an ecologist at the Universidad Nacional Autónoma de México in an accompanying article in Science. “What’s really scary is that the model only looked at three of the 18 contributions to human well-being we’ve identified,” says Balvanera in an interview.
(Read what E.O. Wilson, one of the great figures in biology and conservation, thinks we should do about saving nature.)
Looking at every patch of Earth
The decline of nature is clear—we’ve lost 85 percent of all wetlands, for example— but the impacts of that loss are not, she says. The new model makes those kinds of impacts tangible by showing how many people are affected and where. It is also fine-scaled enough to reveal the effects of the loss of nature for every 300 by 300 meter patch of the Earth. That shows where restoring nature or preventing its loss provide the biggest benefits, says Balvanera.
The magnitude of those impacts won’t be mitigated by technology or infrastructure, she says. South Asia would have to build thousands of water treatment plants to provide the clean water people need, while nature can do it for free. Madagascar can’t afford to build seawalls to protect its coasts but it could restore its coastal communities of mangroves and seagrasses.
“This is the kind of tool that looks at the plausible futures based on science that can help governments avoid bad outcomes,” says Watson.
The model is available online so anyone can explore the potential impacts of different policy decisions, including unintended consequences. For instance, if society emphasizes bioenergy as a way to combat climate change, the model can show the potential impacts of that decision on biodiversity and food security, Watson says.
Original Article: https://www.nationalgeographic.com/science/2019/10/billions-face-water-food-insecurity/