Climate Wire | The controversial idea of cooling the planet’s climate by human means is likely to require a much longer global commitment than policymakers and the general public realize.
If world leaders decide to use solar geoengineering to meet international climate goals, they could be trapped in it for more than a century, research suggests. Statistically long timeframes further complicate the debate about geoengineering and its feasibility.
Geoengineering is “often communicated as a temporary stopgap measure, implying that it is relatively short-lived and short in the sense of decades,” said lead study author and European Research Institute of Advanced Studies. Susanne Baur, a doctoral candidate at the Training Center, said. She holds a PhD in Scientific Computing in France. “So when we started looking at these paths and extrapolated them a bit longer, we found that often they weren’t really that short.”
The public may not be aware of the extent of our commitment to solar geoengineering, or its risks, including the need for long-term international cooperation.
“If you have to maintain a system like this for this long, it only increases the chances of something bad happening,” Bauer said.
Solar geoengineering refers to a type of climate geoengineering aimed at manipulating the amount of solar radiation hitting the earth. The most commonly discussed strategy is to blow specialized reflective aerosols into the atmosphere to direct sunlight away from the Earth and cool the planet.
It’s just an idea for now. And it’s very controversial. The risks and side effects of solar geoengineering range from potential damage to the Earth’s ozone layer to inadvertent changes in global precipitation patterns.
Once started, it is dangerous to stop unless enough carbon is pumped out of the atmosphere to bring the Earth’s temperature below safe thresholds. It can skyrocket and go faster than life can adapt. This is a concept known as “terminating shock”.
This risk has led scientists to seek international debate and agreement on the regulation of geoengineering experiments and deployments.
New study published in the journal on March 28 earth system dynamicsanalyzes how solar-geoengineering can be used to meet climate goals, and how long the world must maintain practice to meet the goals.
Research shows that the timeframes span a very wide range. Solar-geoengineering could become unnecessary if countries rapidly reduced emissions and carbon in the atmosphere.
However, based on the carbon reduction commitments made by countries under the 2015 Paris Agreement, keeping global warming within the 1.5°C threshold would require sustaining solar geoengineering for at least a century. Studies have shown that it is likely that
The study models hundreds of potential geoengineering scenarios to determine how quickly global emissions decline, how much carbon is removed from the atmosphere each year, and how the climate system physically responds. and other factors, but these are still uncertain.
Projected timelines range from no geoengineering to hundreds of years, but very few scenarios result in timelines of less than 100 years. These scenarios generally assume very aggressive climate action.
The study also found that if countries meet their climate goals under the Paris Agreement, solar-geoengineering will be needed for at least a century before the world can safely come to a halt and global temperature rise stays below 1.5C. I also made it clear that
The threshold is the most ambitious goal of the Paris Agreement. And it’s getting more and more obscure. The latest report from the UN’s Intergovernmental Panel on Climate Change, released in March, warned that the world could exceed its temperature targets within her decade. Even if we cut our carbon footprint immediately, the world is likely to cross the 1.5 C threshold, at least temporarily, the report says.
Overshoot need not be permanent. Countries can use various technologies to suck carbon dioxide out of the atmosphere, lowering global temperatures in the process. However, some consequences of climate change, such as sea-level rise, are irreversible and irreversible on human timescales.
Solar-geoengineering could prevent overshoot by temporarily cooling the Earth’s climate, keep global temperature rise below 1.5 C, and lead world leaders to reduce emissions and We are working on removing carbon dioxide.
Ultimately, after global emissions are net zero and sufficient amounts of carbon are removed, the world may stop using geoengineering without the planet warming up again. But it’s unclear how long it will take to get there.
Few studies have attempted to identify when geoengineering is needed, Bauer says, but the question is essential. Long-term use of geoengineering raises potential risks and increases the need for international cooperation, which may be unpredictable over the long term.
“It is very risky to maintain this international cooperation over a technology like this where geopolitical interests are involved,” Bauer said.
Chris Field, an earth system scientist at Stanford University who was not involved in the study, said long-term frameworks for international cooperation on other issues have been successful for decades. Still, “it makes perfect sense to me that long-term governance concerns are justified,” he said.
Field chaired the committee of the National Academy of Sciences, Academy of Engineering and Medicine, which released the 2021 report on Solar Geoengineering. The report suggested that the concept deserved more scientific research and prompted the U.S. government to develop a well-funded national research program. Careful governance and regulation along the way.
The new study “emphasizes that its research agenda is broad and needs to address issues such as long-term governance challenges and how long governance challenges will last,” Field said. increase.
Experiments investigating the physical effects of solar geoengineering are often of more scientific and public interest than ethical or logistical issues, he added.
“Sometimes enthusiasm for them [issues] It’s ahead of enthusiasm for other kinds of research on unintended consequences, social licensing, and governance issues that are likely to really matter,” Field said.
Reprinted from E&E News with permission of POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environmental professionals.
