WASHINGTON – In the face of the devastating effects of climate change, prominent research institutions and government agencies are focusing new money and attention on an idea that was once dismissed as science fiction: artificially cooling the planet in hopes of giving humankind more time to reduce greenhouse gases Emissions.
This strategy, known as solar climate intervention or solar geoengineering, involves more of the solar energy being reflected back into space. It drops global temperatures abruptly in a way that mimics the effects of ash clouds caused by volcanic eruptions. The idea has been derided as a dangerous and illusory solution that would encourage people to continue burning fossil fuels while exposing the planet to unexpected and potentially threatening side effects.
As global warming continues, causing more devastating hurricanes, forest fires, floods, and other disasters, some researchers and policy experts believe that geoengineering concerns should be outweighed by the need to better understand it, if the consequences of climate change do so get bad that the world can’t wait to find better solutions.
“We are faced with an existential threat and must examine all options,” said Michael Gerrard, director of the Sabin Center for Climate Law at Columbia Law School and editor of a book on the technology and its legal implications. “I compare geoengineering to chemotherapy for the planet: if all else fails, give it a try.”
On Wednesday, a nonprofit called SilverLining announced $ 3 million research grants to Cornell University, the University of Washington, Rutgers University, the National Center for Atmospheric Research, and others. Work focuses on practical issues such as the altitude of the atmosphere to inject sunlight-reflecting aerosols, how particles of the correct size are shot into clouds to make them brighter, and the impact on global food supplies.
Kelly Wanser, managing director of SilverLining, said the world is running out of time and protecting people requires trying to understand the consequences of climate intervention. She said the goal of what has been dubbed the Safe Climate Research Initiative is “to try to get the best people to deal with these issues.”
The research announced on Wednesday adds to a growing body of work that is already underway. In December, Congress gave the National Oceanic and Atmospheric Administration $ 4 million to research the technology. NOAA will also collect data that can be used to determine whether other countries are stealthily using geoengineering. And Australia is funding experiments to see if and how technology can save the Great Barrier Reef.
“Decarbonization is necessary, but it will take 20 years or more,” said Chris Sacca, co-founder of Lowercarbon Capital, an investment group that is one of SilverLining’s backers, in a statement. “If we do not investigate climate protection measures such as the reflection of sunlight now, we will give off countless life, species and ecosystems to the heat.”
One way to cool the earth is to inject aerosols into the upper layer of the atmosphere, where these particles reflect sunlight away from the earth. This process works, according to Douglas MacMartin, a mechanical and aerospace engineering researcher at Cornell University, whose team was funded. “We know with one hundred percent certainty that we can cool the planet,” said Dr. MacMartin in an interview.
What is still unclear, he added, is what will happen next.
The temperature, said Dr. MacMartin is a proxy for many climate effects. “What does it do with the strength of hurricanes? What does it do with the agricultural yield? What does it do with the risk of forest fires? “
To answer these questions, Dr. MacMartin modeled the specific weather effects of injection of aerosols into the atmosphere over different parts of the world and also at different altitudes. “Depending on where you put it, you will have different effects on the monsoons in Asia,” he said. “They will have different effects on the Arctic sea ice.”
Another institution receiving funding under the new initiative is the National Center for Atmospheric Research in Boulder, Colorado, funded by the National Science Foundation and which its researchers call the most advanced Earth system model in the world.
The SilverLining grant paid the center to run and analyze hundreds of simulations of aerosol injection to test the effects of extreme weather conditions around the world. One goal of the research is to find a sweet spot – the amount of artificial cooling that can reduce extreme weather events without changing regional precipitation patterns or similar effects more.
“Is there at least in our model world a way to see whether we can achieve one thing without triggering too much of the other?” said Jean-Francois Lamarque, director of the Center’s Climate and Global Dynamics Laboratory.
NOAA begins its own research in solar geoengineering. And in August, the agency announced that it would start measuring aerosol levels in the stratosphere and create a baseline so the agency can determine if those levels change later.
One of the benefits of this information, according to Troy Thornberry, a scientist at NOAA who studies atmospheric composition and chemical processes, is that NOAA can determine if aerosol levels are rising – a sign that another country may be intentionally injecting aerosol without it to announce.
Injecting aerosol into the stratosphere isn’t the only way to redirect more sun rays back into space. The Australian government is funding research into what is known as “ocean cloud lightening,” which aims to make clouds more reflective by spraying salt water into the air. The goal is to get salt particles to act as nuclei in these clouds and encourage the formation of many tiny water droplets, thereby increasing the brightness of the clouds.
Australian researchers hope the technology can save the Great Barrier Reef. Rising water temperatures during so-called marine heatwaves accelerate reef death, and as ocean clouds become more reflective, water temperatures may be cooled enough to slow or stop this decline.
In March, Daniel Harrison, a biological oceanographer at Southern Cross University in Australia, tested the technology by spraying water into the air with 100 nozzles.
“The results have been very encouraging,” said Dr. Harrison in a telephone interview. One of the challenges will be getting enough technology to use it to make a difference. He estimated that it would likely take 500 to 1,000 stations such as barges or platforms spraying water, or fewer moving ships, to cover the entire reef.
The University of Washington is also working on ocean cloud lightening and has again received a SilverLining scholarship. Sarah Doherty, program manager for the university’s Marine Cloud Brightening project, said the challenge is to build spray nozzles that consistently produce particles of the correct size. between 30 and 100 nanometers and find ways to keep them from sticking together.
The project aims to understand how the clouds react and also to predict the regional and global climate reaction. Dr. Doherty said her team hoped to have the spray system tested on site over the next 12 to 18 months.
“The whole idea of the research we do,” she said, “is to make sure you don’t run out and accidentally change things in ways that will cause harm.”
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