They’ve Got a Plan to Fight Global Warming. It Could Alter the Oceans
By Brad Plumer and Raymond Zhong. The New York Times.
Excerpt: In a quiet patch of forest in Nova Scotia, a company is building a machine designed to help slow global warming by transforming Earth’s rivers and oceans into giant sponges that absorb carbon dioxide from the air. When switched on later this year, the machine will grind up limestone inside a tall green silo and release the powder into the nearby West River Pictou, creating a chalky plume that should dissolve within minutes. ...adding limestone converts some of that carbon dioxide into a stable molecule that instead stays underwater and washes into the sea, where it should remain trapped for thousands of years. ...Toying with ocean chemistry also carries unknown risks. Some environmental groups worry that even early experiments with these techniques could threaten fish and other aquatic life. ...In the 1970s and ’80s, industrial pollution made rainfall more acidic, which poisoned lakes and streams around the world. Some of the hardest-hit countries, including Norway, Sweden and Canada, began adding limestone to their waterways to restore the pH balance and help fish populations recover. It worked. ...adding limestone also helped rivers sequester more carbon....