'Once-Unthinkable' Ways We Can Cool the Planet

Reversing course on climate change requires a global reduction in GHG emissions that we're just not keeping pace with—and per the Wall Street Journal, desperate times call for desperate measures, at least to some scientists. The urgency of the times has prompted them to think way outside the box, sometimes hitting on taboo and untested ideas, which are now being more readily funded to study. The National Academy of Sciences recommended a "cautious approach" to testing newer technologies, like solar geoengineering, in 2021. Here are some of the more interesting ways researchers say we can slow down the effects of global warming, some of which are already being tested out.

• Brighten marine clouds: In a $64.55 million project, researchers are testing the effects of hosing a briny mixture into the air via high-pressure nozzles over the Great Barrier Reef. The hope here, according to WSJ, is that this will brighten low-altitude marine clouds, reflecting away sunlight and shading the reef, which is experiencing mass die-off from warming temperatures.
• Reflect sunlight with shiny stuff: The process has a more formal moniker, solar radiation management, but also works by reflecting the sun's rays from the planet to cool Earth's atmosphere. This entails injecting a cloud of tiny reflective particles 60,000 feet into the upper atmosphere so they can reflect sunlight back into space. A group called the Union of Concerned Scientists isn't so much into testing SRM and cloud brightening due to unknown environmental risks among other things, and calls for strict oversight.
• Shield glaciers with underground walls: Glaciers are melting at astounding rates, and warmer ocean temperatures are accelerating the process below the surface. Per Discover Magazine, a paper in Nature suggests building enormous underwater walls as a buffer can slow this down. The authors say such barriers could delay melt for centuries in parts of Greenland and Antarctica, "buying time to address global warming." But building the wall, for now, remains a theory.
• Store carbon in mechanical trees: Arizona State University engineering professor Klaus Lackner developed giant mechanical trees that capture and store carbon. The university's first tree, which is 33 feet high, captures 200 pounds of carbon per day. On the flip side, carbon capture isn't a "silver bullet," according to Howard Herzog of the MIT Energy Initiative, and though the industry is flush with funding, some consider it a distraction from simpler solutions, CNN reports.
• Dump sodium hydroxide into the ocean: WSJ describes this one as giving the ocean a giant dose of Tums for its acidity problems. This summer, researchers plan to pour 6,000 gallons of chemicals, a liquid solution of sodium hydroxide, south of Martha's Vineyard. Along with lowering acidity along the surface water, the effect may absorb CO2, storing 20 metric tons of it in the ocean.

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