A new article in the May issue of Nature communications demonstrates why keeping local lakes and other water bodies clean produces cost-effective benefits locally and globally.
A single season of a lake or body of water with a harmful algal bloom that results in public no-drink orders, damage to fishing activity, loss of recreational opportunities, decrease Property value and an increased likelihood of low birth weight in infants born to mothers exposed to polluted water bodies are just a few of the reasons why clean water is important.
Almost everyone wants their local lake or stream to be clean and usable for drinking, fishing, swimming, and entertainment. But previous cost-benefit studies have shown that the costs of protecting local water sources often outweigh the benefits.
Not so quickly say the authors. One of the reasons that previous studies have shown that the costs outweigh the benefits is that not all benefits, especially global benefits, have been analyzed by economists.
New research, led by John A. Downing, director of the University of Minnesota Sea Grant, has found that adding up the global financial benefits of clean water shows that keeping water clean can help slow climate change, by saving trillions of dollars. Using a case study of Lake Erie as an example, the authors also found that the global climate change value of protecting and preventing algal blooms in this Great Lake was ten times the value of l use of the beach or sport fishing.
“Surface water is one of the Earth’s most important resources,” said Downing, who is also a lakes scientist at the Duluth Large Lake Observatory at the University of Minnesota. “Yet people have mistakenly assumed that protecting our water costs more than it is worth. Our research shows that there is significant local and global value in protecting water quality. local.”
One reason for this, the authors said, is that scientists and economists had previously only considered a narrow range of local benefits when calculating the results of good water quality. Downing and his co-authors sought to calculate the potential global benefits.
Locally, cleaning up or keeping a local lake or body of water free of unwanted nutrients – what scientists call eutrophication – is obviously good for people who use or want to access that particular body of water. Globally, it’s also good for reducing the amount of greenhouse gas methane that is released into the atmosphere from this eutrophic body of water.
Methane is a more potent greenhouse gas than carbon dioxide because it has a much higher heat-trapping capacity and has about 21 times the global warming potential of carbon dioxide. Less methane in the atmosphere can help slow global warming.
The authors sought to answer the question: is keeping a local water body clean worth the cost?
The cost of climate change comes from health care costs, damage to urban infrastructure, agricultural damage, damage from catastrophic storms, negative impacts on recreation, forestry, fishing, energy systems, systems water, construction and coastal infrastructure.
“We calculated the global climate damage from methane emissions from eutrophic lakes and calculated the damage that would be avoided by preventing the increase in emissions from 2015 to 2050,” Downing said. “If we could keep methane emissions at current levels rather than the projected 20-100% increase by 2050, the value of avoiding the resulting damage could reach $ 24 trillion.” The authors estimated that the costs of global climate change due to eutrophication from 2015 to 2050 were $ 81 trillion.
The authors’ analysis shows that local protection of water quality has global economic implications. The substantial emissions they document from lakes and reservoirs and the potential for increased emissions suggest that there is considerable value to be gained by improving water quality in lakes and reservoirs and preventing further deterioration. .
“It is not possible to avoid all emissions from lakes and reservoirs, but with a concerted effort it may be possible to prevent the increase in emissions or even reverse it,” Downing said.