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An Agreement To Protect Biodiversity | Earth Wise

January 18, 2023 By EarthWise Leave a Comment

The UN Biodiversity Conference in Montreal in December concluded with a historic deal aimed at stemming the rising tide of extinctions.  Nearly 200 countries signed on to the agreement to protect 30% of the Earth’s land and sea by the end of this decade.

Part of the agreement also pledges that countries will reduce fertilizer runoff from farms by 50%, reduce the use of harmful pesticides by 50%, and stem the flow of invasive species. 

Of course, all of these promises are only words unless they are backed up by actions and actions cost money.  The agreement promises to direct $200 billion a year towards biodiversity by the end of this decade.  Wealthy countries were urged to provide $100 billion a year to fund the actions of poorer countries, but they resisted the pressure.  Eventually, they did agree to send $30 billion a year to developing countries by 2030.

It is a significant step forward to establish clear targets for stopping biodiversity loss.  However, the ultimate success of the pact will depend on the willingness of countries to cooperate and compromise.

According to UN estimates, about a million species across the globe face extinction as a result of rising temperatures, air and water pollution, invasive species, and habitat loss due to development.   At present, only 16% of land and 8% of the oceans are within protected areas. 

The UN Environment Program stated that “for far too long humanity has paved over, fragmented, over-extracted, and destroyed the natural world on which we all depend.  Now is our chance to shore up and strengthen the web of life, so it can carry the full weight of generations to come.”

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In Historic Deal, Countries Agree to Protect 30 Percent of Earth to Halt Biodiversity Loss

Photo, posted August 13, 2015, courtesy of Andrew H via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rivers Changing Color | Earth Wise

February 10, 2021 By EarthWise Leave a Comment

Why do rivers change colors?

A recent study, published in Geophysical Research Letters, found that one-third of large American rivers have had significant changes of color over the past 30 years.  Rivers can appear to be shades of blue, green, and yellow and we tend to expect healthy rivers to have colors in shades of blue.  According to the new study, only 6% of American rivers are dominantly blue.

The study looked at 235,000 Landsat images taken from 1984 to 2018.  The results are that 56% of rivers studied were dominantly yellow, 38% dominantly green, and 6% blue.  Over the 34 years studied, 33% of the rivers had significant changes in color. About 21% became greener and 12% more yellow. 

The chief causes of color changes in rivers are farm fertilizer runoff, dams, efforts to fight soil erosion, and climate change.  Climate change increases water temperature and rain-related runoff.

Color changes are not necessarily a sign of poor river health, but dramatic changes could point to issues that need attention.  A river can change color based on the amount of sediment, algae, or dissolved organic carbon in the water.   If a river becomes greener, it can often mean large algae blooms are present that cause oxygen loss and can produce toxins.  On the other hand, rivers that are getting less yellow demonstrate the success of regulations to prevent soil erosion.

The study of river colors can pinpoint which rivers are undergoing rapid environmental change.  What the study does not provide is information on water quality.  Water quality measurements will be important to determine the health of many of the rapidly changing rivers.

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One Third of U.S. Rivers Changed Their Color, Three Decades of Satellite Images Show

Photo, posted July 6, 2016, courtesy of Jeffrey Beall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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