Phys.org April 11, 2024 Marine cloud brightening is a proposed method to tackle warming through injecting aerosols into marine clouds. However, it is unclear how aerosols influence clouds. An international team of researchers (USA – University of Birmingham, NASA GSFC, Greenbelt, MD, University of Maryland Baltimore County, UK, Switzerland) used satellite observations of volcanic eruptions in Hawaii to quantify the aerosol fingerprint on tropical marine clouds. They observed a large enhancement in reflected sunlight, mainly due to an aerosol-induced increase in cloud cover. This suggested that the current level of global warming is driven by a weaker net radiative forcing […]
Category Archives: Geoengineering
Clouds disappear quickly during a solar eclipse, shows study
Phys.org February 12, 2024 Clouds affected by solar eclipses could influence the reflection of sunlight back into space and might change local precipitation patterns. Satellite cloud retrievals have so far not taken into account the lunar shadow, hindering a reliable spaceborne assessment of the eclipse-induced cloud evolution. Researchers in the Netherlands used satellite cloud measurements during three solar eclipses between 2005 and 2016 that have been corrected for the partial lunar shadow together with large-eddy simulations to analyze the eclipse-induced cloud evolution. The corrected data revealed that, over cooling land surfaces, shallow cumulus clouds start to disappear at very small […]
Scientists evaluate Earth-cooling strategies with geoengineering simulations
Phys.org August 23, 2022 Making informed future decisions about solar radiation modification (SRM)/solar geoengineering requires projections of the climate response and associated human and ecosystem impacts using climate models and simulations. SRM modeling simulations to date typically consider only a single scenario, often with some unrealistic or arbitrarily chosen elements (such as starting deployment in 2020) and have often been chosen based on scientific rather than policy-relevant considerations. An international team of researchers (USA – Cornell University, Indiana University, NCAR, Duke University, American University, UCLA, Japan) list several scenarios that explore different choices, and present new climate model simulation results. […]
Geoengineering could return risk of malaria for one billion people
Phys. org April 20, 2022 Solar geoengineering is often framed as a stopgap measure to decrease the magnitude, impacts, and injustice of climate change. However, the benefits or costs of geoengineering for human health are largely unknown. An international team of researchers (USA – Georgetown University, University of Maryland, Rutgers University, University of Florida, Bangladesh, Germany, South Africa) has projected how geoengineering could impact malaria risk by comparing current transmission suitability and populations-at-risk under moderate and high greenhouse gas emissions scenarios with and without geoengineering. They showed that if geoengineering deployment cools the tropics, it could help protect high elevation […]
‘Sky is not the limit’ for solar geoengineering
Science Daily March 14, 2022 In a report a team of researchers in the US (Yale College Harvard University, AIAA, industry) responded to a question posed by the US National Academy of Science, Engineering, and Medicine in a landmark study in March 2021 which recognized the need for additional research on the viability of depositing aerosols well above 20 km to deflect incoming sunlight and countervail global warming. According to the team airliners and military jets routinely cruise near 10 km, whereas 20 km is the realm of high-flying spy planes and drones. Planning to fly hundreds of thousands of […]
A proposal to use electric charges to encourage raindrops to form in clouds
Phys.org February 9, 2022 Researchers in the UK calculated the electrostatic forces between two water spheres that have not yet grown large enough to be described as raindrops. They found that the greater the variation in charges between droplets, the stronger the attraction between them. And that led them to suggest that if the variation was increased via an electric charge, the droplets would merge, leading to the formation of rain drops. As droplets merge and grow in size, additional electric charge should result in mergers between droplets until they become large enough for gravity to take over and they […]
Dimming The Sun Is a Dangerous Gamble And Should Be Banned, Scientists Warn
Science Alert January 18, 2022 In an open letter more than 60 policy experts and scientists warned that planetary-scale engineering schemes designed to cool Earth’s surface and lessen the impact of global heating are potentially dangerous and should be blocked by governments. According to the signatories there are several reasons to reject such a course of action – artificially dimming the Sun’s radiative force is likely to disrupt monsoon rains in South Asia and western Africa, ravage the rain-fed crops upon which hundreds of millions depend for nourishment, if SRM were terminated for any reason, there is high confidence that surface […]
Before geoengineering to mitigate climate change, researchers must consider some fundamental chemistry
Phys.org November 22, 2021 Geoengineering using sulfuric acid would happen in the stratosphere. The major inputs for the creation of sulfuric acid are sulfur dioxide, hydroxyl radicals which create hydroxysulfonyl radical (HOSO2). This in turn reacts with oxygen to create sulfur trioxide (SO3) which results in sulfuric acid when it reacts with water. Aerosols formed from the sulfuric acid can reflect sunlight. These reactions create acid rain in the troposphere. If the same chemistry would work in the stratosphere is unknown. An international team of researchers (USA -University of Pennsylvania, Spain) has shown that the photodissociation of HOSO2 occurs primarily […]
In Science magazine, scholars call for more comprehensive research into solar geoengineering
Phys.org November 11, 2021 As the prospect of average global warming exceeding 1.5°C becomes increasingly likely, interest in supplementing mitigation and adaptation with solar geoengineering (SG) responses will almost certainly rise. For example, stratospheric aerosol injection to cool the planet could offset some of the warming for a given accumulation of atmospheric greenhouse gases. However, the physical and social science literature on SG remains modest compared with mitigation and adaptation. An international team of researchers (USA – Harvard university, Duke University, research organization, American University, Georgia State University, UC San Diego, Yale University, NCAR, Duke University, Italy, India, Switzerland, Germany, […]
A new method to trigger rain where water is scarce
Phys.org May 6, 2021 Artificial charge release is an unexplored potential geoengineering technique for modifying fogs, clouds, and rainfall. To evaluate the effectiveness of the method an international team of researchers (UK, Finland) developed a small charge-delivering remotely piloted aircraft. It carried controllable bipolar charge emitters (nominal emission current ±5 μA) beneath each wing, with optical cloud and meteorological sensors integrated into the airframe. Meteorological and droplet measurements were demonstrated to 2 km altitude by comparison with a radiosonde, including within cloud, and successful charge emission aloft verified by using programmed flight paths above an upward-facing surface electric field mill. […]