September 25, 2023: Technologies to block the sun and cool Earth, salamander dads are eating their young, and lifesaving vaccines to get during pregnancy. —Andrea Gawrylewski, Chief Newsletter Editor | | | Solar radiation management (SRM) includes techniques that change the heating of Earth's surface. For example, releasing sulfur dioxide into the atmosphere forms aerosols that reflect the sun's rays; spraying sea salt 1,000 meters in the air seeds reflective cloud droplets; and spraying silver iodide particles into cirrus clouds breaks them up so more heat can be released from the planet's surface. Studies suggest that if SRM were deployed at sufficient scale it could slow warming and even cool the planet a bit. BUT, such interference in the natural atmosphere could have disastrous effects, like throwing global rainfall patterns out of whack and endangering people and crops.
Why would we do this? Humans are unlikely to reduce emissions quickly enough to keep global temperature increases below 1.5 degrees C, and some scientists say SRM might be less scary than allowing warming to continue unabated. Plus, moving away from fossil fuels could take decades, and the CO2 emitted until then could make warming worse.
What the experts say: More than 400 scientists have signed an open letter urging governments to adopt a worldwide ban on SRM experiments. But other scientists are proceeding, if reluctantly, building models that might accurately forecast the climate effects of such approaches. | | | Numbers of eastern hellbender salamanders have plummeted in recent decades, with only about 126 streams now harboring healthy populations, down from 570 streams in eastern and central U.S. Monitoring salamander nests in streams in southwestern Virginia, researchers found that larva didn't survive in 60 percent of nests. The males, which usually guard and protect clutches of eggs, were eating hundreds of eggs instead.
Why this is happening: Cannibalism of offspring isn't unusual among animals, especially when times are lean and parents suspect their eggs won't survive. In the study, whole-clutch cannibalism was three times more common in areas with low upstream forest cover than in those with greater coverage. Vegetation helps to keep their nesting sites free of silty runoff, and more trees keep water temperatures cooler and more oxygen-rich.
What the experts say: Restoring forest cover and putting in protections around streams will take decades, says Bill Hopkins, an ecologist at Virginia Tech, who ran the study. In the short term, conservationists could keep the numbers up by rearing hellbender larvae for release and avoiding this danger at the nest. | | | • If you're pregnant, these vaccines could save your and your baby's life. | 8 min read | | | • Conformal field theory, a type of quantum physics, can explain why coffee flows slower through a narrow filter (but make sure you've had your morning cup before diving into this article). | 10 min read | | | • Even though it only has 1,000 neurons and no central brain, Caribbean box jellyfish (Tripedalia cystophora) are capable of adaptive learning (learning from experience). | 4 min read | | | A Caribbean box jellyfish. Credit: Jan Bielecki/Getty Images | | | • Vivitrol, a monthly injection of long-acting naltrexone, is the opioid treatment preferred by the criminal prosecution system, including jails, prisons, probation officers and drug courts. But people on Vivitrol are actually more than twice as likely to overdose than on other opioid treatments, according to a new study, writes Maia Szalavitz who is the author of Undoing Drugs: The Untold Story of Harm Reduction and the Future of Addiction. "Physicians and people using this drug must be made aware that the evidence heavily favors methadone and buprenorphine above and beyond any other treatment approach," she says. | 5 min read | | | Interested in reading more about the impacts of climate change and how we might counteract them? I recommend this special issue on climate change and what we're doing to solve it. | I've loved reading all of your emails letting me know if you'd be up for joining a mission off-Earth. A recurring theme I saw was a great love and respect for our home planet. I agree wholeheartedly! Email me anytime: newsletters@sciam.com. See you tomorrow. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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