TITLE: Bay Area hosts first-in-nation experiment to slow global warming — by helping clouds deflect sunlight
https://www.sfchronicle.com/weather/article/geoengineering-cloud-research-alameda-19368199.php
EXCERPTS: In Alameda, scientists are embarking on a novel attempt to cool the Earth — by spraying salt into clouds.
The work, known as marine cloud brightening, is controversial and is just one method of geoengineering — which describes interventions meant to slow Earth’s warming. But proponents say the technology may be needed to mitigate climate change.
To brighten clouds, researchers spray microscopic sea salt into the air over the ocean to boost clouds’ reflectivity. This means less sunlight is absorbed, leading to a planetary cooling effect.
On Tuesday, scientists from the Marine Cloud Brightening Program scaled up their research from the laboratory to the flight deck of the decommissioned aircraft carrier Hornet in Alameda, kicking off a field campaign that will continue until autumn.
The scientists from the University of Washington are experimenting with the size and concentration of sea salt particles emitted from a spray machine. Cloud brightening has been simulated by computer models, but the field work is the first of its kind in North America and only the second of its kind in the world. The foggy climate of the Bay Area, the researchers say, is ideal for these experiments.
The group hopes to refine their formula for artificial sea salt and determine whether their recipe could brighten clouds and cool the planet in a significant way.
In order for clouds to form, water vapor droplets need a surface on which to stick. Over land, dust, pollen and ash serve as seeds for cloud droplets, while marine clouds are mainly composed of sea salt particles.
Scientists hypothesize that by manually increasing the number of particles in the atmosphere, clouds will reflect more sunlight back to space, causing Earth to cool.
When clouds reflect more sunlight, they look brighter and whiter to the human eye.
“A white car in a parking lot on a sunny day is going to be cooler than a black car … same idea,” said Lynn Russell, an atmospheric chemist at UC San Diego’s Scripps Institution of Oceanography, who is not involved in the project.
Water vapor is always present in the atmosphere, but clouds can be created only when particles like dust or salt are present.
But scientists are just beginning to test cloud brightening in the real world, and they aren’t yet sure whether it will actually work. Simulations project that if 15% of Earth’s marine clouds were brightened, the globe would cool by roughly a degree, said Rob Wood, the lead scientist for the project and a professor at the University of Washington.
“If you increase the number of cloud droplets by increasing the number of sea salt particles, it’s like increasing the number of mirrors to reflect sunlight back to space,” Wood said.
In fact, particles from human pollution, such as wood burning and vehicular exhaust, provide a cooling, a slight offset to the greenhouse warming effect. Bad air quality is linked to health problems like asthma, so over the last decades, officials have ratcheted up regulations, and global air quality has generally improved. But recent studies find clouds are becoming less reflective as pollution declines, accelerating Earth’s warming trend.
“How much extra warming we get now from aerosol reductions is kind of telling us how much cooling we could have if those aerosols were somehow returned into the system,” Wood said.
One way to do that: Seed clouds with salt.
From a large machine resembling a giant snow maker, the group at the Hornet sprays salt water into the air. As the salty plume moves downwind, the water evaporates, leaving behind tiny salt particles nearly a thousand times smaller than the width of a human hair. In the coming months, the scientists will document what happens in the atmosphere.
TITLE: The hard lessons of Harvard’s failed geoengineering experiment
https://www.technologyreview.com/2024/04/04/1090626/the-hard-lessons-of-harvards-failed-geoengineering-experiment/
EXCERPT: Hundreds of researchers from a variety of disciplines have signed an open letter calling for an “International Non-Use Agreement on Solar Geoengineering,” stating that governments should commit to “ban outdoor experiments of solar geoengineering.”
Jennie Stephens, a professor of sustainability science and policy at Northeastern University, was one of the letter’s signatories. She argues that the SCoPEx experiment was particularly dangerous, because the funding, attention, and prestige of Harvard conferred legitimacy on planet-scale interventions that, to her mind, can never be safely governed or controlled.
She argues that even if the researchers have the best of intentions, solar geoengineering would ultimately be deployed by people or nations with money and power in ways that most benefit their interests, even if it meant disastrous consequences for other areas. Some research, for instance, suggests that solar geoengineering could significantly reduce rainfall in certain areas and might reduce the yields of some staple crops. While one block of nations might decide to use geoengineering to ease heat waves, what if that reduced the summer monsoons and the food supplies across parts of India or West Africa?
“There’s no way to even imagine deploying it on a global scale so that everybody would benefit,” she says. “Some people would be screwed, and some people may have reduced suffering. So it’s creating one more mechanism by which to interfere with the Earth systems and then privilege some and disadvantage others.”
But many believe it’s essential to learn more about the role that solar geoengineering could play in easing global warming, and whether the side effects could be moderated. There’s a simple reason: if it does work well, it could save many lives and ease suffering as climate change accelerates.
For these observers, then, the question is: What lessons can be drawn to ensure that other experiments can go forward? And perhaps of equal importance: What lessons shouldn’t be drawn from [Harvard’s] SCoPEx [geoengineering experiment]?
Some researchers in the field fear that the broader takeaway from the termination of the project will be that the Harvard team chose to be too open about its intentions.
The “organized opposition to even the concept of outdoor experiments” makes it difficult for other research groups to pursue similar work and “may increase the probability of rogue actors,” says Michael Gerrard, faculty director of Columbia University’s Sabin Center for Climate Change Law, who served on the advisory committee. He notes that such activities are largely unregulated.
TITLE: US: Tennessee Senate passes bill banning geoengineering amid ‘chemtrails’ conspiracy theories
https://www.wionews.com/science/us-tennessee-pass-geoengineering-ban-as-chemtrails-conspiracy-theories-rise-706959
EXCERPT: On April 1, the Tennessee state House of Representatives passed a bill to prevent geoengineering. In geoengineering, the atmosphere is intentionally modified to counteract global warming.
The bill targets various methods of geoengineering, including theoretical ideas about cooling the climate by solar radiation modification, cloud seeding, etc.
While the motive of the bill seems to be straightforward: to stop geoengineering, lawmakers discussed the proposal straddled between fact and fiction because most geoengineering options are theoretical and untested.
Many of the concepts grouped together under the broad term "geoengineering" are little more than the wild notions that scientists created while trying to figure out how to slow down global warming.
Some suggested that solar geoengineering projects are already underway and others referred to fears and misunderstandings that appeared to stem from the “chemtrails” conspiracy theory.
“This will be my wife’s favourite bill of the year. She has worried about this, I bet, 10 years. It’s been going on a long, long time. If you look up — one day, it’ll be clear. The next day they will look like some angels have been playing tic-tac-toe. They’re everywhere. I’ve got pictures on my phone with X's right over my house. For years they denied they were doing anything,” Republican Sen. Frank Niceley said at a hearing about the bill last month.
The chemtrails theory suggests that airplanes are not making trails of condensation known as contrails but instead disperse government-controlled chemicals. Despite its lack of scientific basis, variations of this theory have gained traction, with some suggesting it ties into weather and climate manipulation. However, experts dismiss these claims as conspiratorial nonsense.
Tennessee is not the only state to enact an anti-geoengineering policy. Illinois, Kentucky, Minnesota, New Hampshire, Pennsylvania, Rhode Island, and South Dakota have seen/introduced similar bills.
The trend is emerging from a mix of conspiracy theories and concerns about the possibility of climate modification taking hold in the public consciousness.