aerosol

Modeling geoengineering

May 19, 2025 By EarthWise Leave a Comment

As the impacts of climate change continue to mount up, there is increasing interest in radical intervention measures designed to keep a lid on rising global temperatures. Such measures are fraught with potential dangers and unintended consequences but there is no guarantee that one or another of them might still be attempted in the future. Increasing international interest in geoengineering as a potential strategy for mitigating climate change has created a pressing need to consider its impact before any potentially irreversible actions are taken.

The Natural Environment Research Council in the UK is funding four research projects aimed at understanding the potential consequences of solar radiation modification (SRM) being deployed in the real world.

SRM consists of methods to reflect some of the Sun’s radiation back into space instead of allowing it to reach and warm the earth.

One approach is stratospheric aerosol intervention in which particles such as sulfates are introduced into the upper atmosphere to reflect sunlight thereby producing a dimming effect. The idea is to mimic the effects of large volcanic eruptions, which naturally send sulfates into the atmosphere.

A second approach is marine cloud brightening, which increases the reflectivity of clouds over the ocean by spraying very small droplets of sea water into the air. The fine particles of sea salt enhance cloud condensation nuclei, producing more cloud droplets and making clouds more reflective.

The research aims to deliver independent risk analyses to inform policymakers about the potential environmental impacts of SRM.

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Scientists to model the impact of controlling Earth’s temperature by reflecting solar radiation

Photo, posted May 6, 2009, courtesy of Denys Zadorozhnyi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fighting fires with man-made wind

March 12, 2025 By EarthWise Leave a Comment

Researchers at Ohio State University have developed a new portable tool that may help firefighters battle blazes more efficiently and with less risk.

Traditional firefighting methods include chemical foams – which are toxic – and the use of hydrants, which can strain water resources. The recent fires in Southern California demonstrated the need for efficient fire suppression methods. The new device works to suppress flames using conductive aerosols, which are small particles that can direct electricity.

The device uses vortex rings – small donut-shaped bands of air – that transform the aerosol particles into short pulses of wind that convert nearby oxygen into ozone. This accelerated airflow generates rapid turbulence, which disrupts the natural combustion process and quickly extinguishes the target fire.

The device resembles a small bucket, attached to an arm brace. Firefighters would aim the bucket toward the fire, and it would use bursts of compressed air to deliver aerosols in an electric arc to fight the fire.

Testing identified a coarse copper solution for the vortex ring material and simulations showed that the device would succeed in suppressing fires. They then worked on optimizing the power and range of the device.

Depending on the size of the fire and number of firefighters, it is likely that several of the devices would be required in a real emergency. According to the developers, the design of the vortex launcher is actually very simple and is very scalable. The device is maneuverable in tight spaces and could be taken through doors and indoor environments. Vortex rings can carry chemical payloads over longer distances than other methods, making firefighters safe by staying further from flames.

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New device uses electrically assisted wind to fight fires

Photo, posted November 12, 2024, courtesy of the USDA Forest Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Geoengineering And Volcanoes

November 14, 2019 By EarthWise Leave a Comment

Solar geoengineering is a theoretical strategy for curbing the effects of climate change by introducing aerosol particles in the upper atmosphere to reflect some of the Sun’s radiation back into space and thereby cool the planet. It would basically be intentionally tinkering with the climate system on a global scale.

The concept is fraught with the danger of unintended consequences and most experts consider the idea almost unthinkable. But there are those who see it as a last resort if all our other efforts to mitigate the effects of climate change are unsuccessful.

Proponents of the idea like to describe the technique as being like a human-made volcano. Major volcanic eruptions spew ash particles into the atmosphere which can linger for as long as a few years. The result is cooler temperatures, sometimes across much of the globe. The Krakatoa eruption of 1883 lowered average Northern Hemisphere temperatures by more than 2 degrees and created chaotic weather patterns until about 1888.

Researchers at the Carnegie Institution and two Chinese research institutions used sophisticated modeling techniques to compare the effects on the climate of a volcanic eruption with long-term geoengineering deployment.

They found that the volcanic eruption created a greater temperature difference between the land and sea than the geoengineering and resulted in very different precipitation scenarios. In both cases, there would be less available water for people on land.

Overall, the study demonstrated that volcanic eruptions are imperfect analogs for geoengineering and that scientists should be very cautious about extrapolating too much from them. It is important to evaluate geoengineering from an informed position, but the truth is that it represents a great and perilous unknown.

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Geoengineering Versus A Volcano

Photo, posted November 1, 2002, courtesy of the NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.