How US is trying ‘sun blocking’ to cool the Earth? Engineer Matthew Gallelli spearheaded a pioneering experiment on a decommissioned aircraft carrier in San Francisco Bay, marking the United States’ inaugural outdoor trial of a technology poised to combat global warming.
The experiment’s objective was to assess a method devised to brighten clouds and deflect a portion of the sun’s rays back into space, offering a temporary remedy to the planet‘s rising temperatures.
How US is trying ‘sun blocking’ to cool the Earth
Evaluating Cloud Brightening Technology
The primary focus of the experiment was to determine the device’s efficacy in consistently dispersing salt aerosols of the correct size within the open environment—an essential precursor to potentially altering cloud compositions over Earth’s oceans, as reported by The New York Times.
The Concept of “Sun Blocking”
Exploring Solar Radiation Modification (SRM) to Combat Climate Change
Within the realm of innovative approaches to mitigating global warming, American scientists are delving into the concept of “sun blocking,” which involves redirecting sunlight away from Earth to cool the planet.
This strategy, known as solar radiation modification (SRM), gained momentum following a White House report expressing openness to researching its feasibility and effectiveness in addressing climate change.
Proposed Methods and Potential Impact
Stratospheric Aerosol Injection and its Environmental Implications
One proposed method under SRM involves stratospheric aerosol injection, wherein airplanes disperse sun-blocking particles like sulfur dioxide into the upper atmosphere.
The objective is to create a reflective mist that shields Earth from the sun’s rays.
This approach’s potential was inadvertently demonstrated following the 1991 eruption of Mount Pinatubo, which temporarily decreased global temperatures by 0.5°C.
Researchers from Yale University have even speculated that this method could aid in refreezing Earth’s poles.
Challenges and Skepticism
Debates Surrounding Large-Scale Deployment and Environmental Risks
Despite the promise of SRM technologies, the UN Environmental Program (UNEP) has cautioned against their large-scale deployment, citing current scientific understanding.
UNEP’s Chief Scientist, Andrea Hinwood, stressed that SRM cannot substitute for the imperative to reduce greenhouse gas emissions.
Nonetheless, Hinwood did not rule out revisiting this stance should global climate action prove inadequate.
Voices of Concern and Caution
Greenpeace International Scientist Expresses Doubts
David Santillo, a prominent scientist at Greenpeace International, voiced significant doubts regarding the feasibility of altering solar radiation to combat climate change.
He highlighted the potential risks associated with employing techniques such as marine cloud brightening on a global scale, cautioning against unpredictable and potentially adverse outcomes.
“You could well be changing climatic patterns, not just over the sea, but over land as well,” Santillo told the New York Times. He emphasized the dangers of such interventions, stating, “This is a scary vision of the future that we should try and avoid at all costs.”
