Nature "Shrinkage" Will Hit Access To Clean Water For Billions

PALO ALTO CA, United States

Researchers from Stanford University have developed a new interactive map measuring nature’s contributions to human well-being suggests that as many as five billion people, particularly in Africa and South Asia, are likely to face food shortages and lack of clean water in coming decades as a result of “shrinkage” in nature.

This new work builds on the first-ever Global Assessment Report on Biodiversity and Ecosystem Services. Released in May 2019, this concluded that human activity has resulted in the severe alteration of more than 75 percent of Earth’s land areas and 66 percent of the oceans, putting a million species at risk of extinction.

The new examination of ecosystem services, published this month, looked at three aspects of nature’s contributions: providing clean water, coastal protection, and crop pollination. The model reveals that parts of Africa and South Asia will be most affected by the decline in nature as these areas are most directly dependent on nature for survival.

In examining clean water sources, the model mapped plants that grow near water resources. The model considered climate, runoff and other factors to estimate how much excess nitrogen fertilizer from upstream farm fields might remain in waterways. The project then overlaid this information with existing data on drinking water sources and produced an estimate of potential exposure to nitrate pollution.

Maps of coral reefs, mangroves, seagrasses, and salt marshes that protect coastal erosion and storm surges were overlaid with maps of where people live on coasts to determine the amount of deterioration over time. Similarly, maps of food crop areas were overlaid with maps of areas of natural habitat.

The model then estimated what human needs would be and compared that to where nature is already providing (or not providing) ecosystem services, revealing gaps between demand and supply.

Using standard scenarios concerning changes in society, demographics, and economics, the research looked at different scenarios of land use, climate and population change through 2050.

“I hope no one is shocked that billions of people could be impacted by 2050,” said Rebecca Chaplin-Kramer a landscape ecologist at Stanford University and lead author of the study.

Patricia Balvanera, an ecologist at the Universidad Nacional Autónoma de México writes in Science Magazine that the study paints a "deeply worrying picture of the societal burdens of losing nature. What’s really scary is that the model only looked at three of the 18 contributions to human well-being we’ve identified.”

The impacts of the decline in nature are not clear but this new model attempts to quantify how many people will continue to be affected and where these populations are located. The resolution of the map could provide clues as to where nature could be restored or could be prevented from further deterioration.

The authors suggest that nature could provide clean water and prevent coastal erosion if the correct measures are taken to restore wetlands and coastal seagrasses, for example.

The global assessment report concluded that sweeping changes are needed in our governance, economic, food production, energy, and other systems. This tool could be used to guide some of those policy decisions.