A Clever But Questionable Approach to Geoengineering

MIT's David Keith says it could be cheaper and easier to stop global warming than you think

2 min read
A Clever But Questionable Approach to Geoengineering

Technology Review editor David Rotman has an unusually reader-friendly article in the issue just out  on what goes by the name, loosely, of "geoengineering"—deliberate efforts to modify earth's atmosphere to counteract the effects of greenhouse gases. In the March issue, Rotman profiles MIT scientist David Keith, a former atomic physicist, and his idea of injecting sulfuric acid into the upper atmosphere, where the sulfur aerosols would reflect incoming solar radiation back into space.

"One of the startling things about Keith's proposal," writes Rotman, "is just how little sulfur would be required. A few grams of it in the atmosphere will offset the warming caused by a ton of carbon dioxide, according to his estimate."

The idea of pumping sulfate aerosols into the atmosphere is not new as such. What does seem novel in Keith's scheme, however, is the disarmingly simply method he proposes for putting them there: Customize standard Gulfstream business jets and have them fly 20 kilometers up to disperse sulfuric acid, which will combine with water to form the reflective sulfate aerosols.

What's not to like in this scenario? The main objections are just those that my fellow energy blogger David Levitan has identified in this space: The impossibility of accurately predicting what the regional impacts of the sulfur pumping would be, and the complete absence of any understanding of its impact on ocean acidification, one of the most serious consequences of carbon dioxide buildup. "It's not possible to use existing models to know how geoengineering might affect, say, India's monsoons or precipitation in such drought-prone areas as northern Africa," Rotman concedes in the end.

For balance, Technology Review also has in its current issue an excellent short commentary piece that makes the case for energy conservation and efficiency (an editorial strategy Scientific American also has adopted when addressing the delicate subject of geoengineering). It won't be enough to just keep trying to marginally reduce our immense greenhouse gas emissions, writes Jane Long, who chairs a California future energy committee and co-chairs the Bipartisan Policy Center's geoengineering task force. "Our first step should be to to commit to never building another energy-inefficient city, building, vehicle, or industry."

Image: Don Bayley/iStockphoto

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Smokey the AI

Smart image analysis algorithms, fed by cameras carried by drones and ground vehicles, can help power companies prevent forest fires

7 min read
Smokey the AI

The 2021 Dixie Fire in northern California is suspected of being caused by Pacific Gas & Electric's equipment. The fire is the second-largest in California history.

Robyn Beck/AFP/Getty Images

The 2020 fire season in the United States was the worst in at least 70 years, with some 4 million hectares burned on the west coast alone. These West Coast fires killed at least 37 people, destroyed hundreds of structures, caused nearly US $20 billion in damage, and filled the air with smoke that threatened the health of millions of people. And this was on top of a 2018 fire season that burned more than 700,000 hectares of land in California, and a 2019-to-2020 wildfire season in Australia that torched nearly 18 million hectares.

While some of these fires started from human carelessness—or arson—far too many were sparked and spread by the electrical power infrastructure and power lines. The California Department of Forestry and Fire Protection (Cal Fire) calculates that nearly 100,000 burned hectares of those 2018 California fires were the fault of the electric power infrastructure, including the devastating Camp Fire, which wiped out most of the town of Paradise. And in July of this year, Pacific Gas & Electric indicated that blown fuses on one of its utility poles may have sparked the Dixie Fire, which burned nearly 400,000 hectares.

Until these recent disasters, most people, even those living in vulnerable areas, didn't give much thought to the fire risk from the electrical infrastructure. Power companies trim trees and inspect lines on a regular—if not particularly frequent—basis.

However, the frequency of these inspections has changed little over the years, even though climate change is causing drier and hotter weather conditions that lead up to more intense wildfires. In addition, many key electrical components are beyond their shelf lives, including insulators, transformers, arrestors, and splices that are more than 40 years old. Many transmission towers, most built for a 40-year lifespan, are entering their final decade.

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