New peer-reviewed research, supported by CONSTRAIN, shows that if solar radiation management – where higher amounts of sunlight are reflected back to space through artificially altering either the Earth’s surface or the atmosphere – is deployed to limit warming to 1.5°C without emissions cuts beyond those currently envisioned by governments, it would have to be maintained for at least a hundred years.
Over 350 emission scenarios are considered in the study that extrapolates emissions from 2030 out to 2500 based on governments’ current climate targets. Most of the scenarios see solar radiation management deployed for 150-300 years. No scenario consistent with current targets sees it deployed for less than 100 years.
“Other studies have laid out additional risks from reliance on such technologies, like termination shock and governance challenges. Our paper adds a perspective on the length of deployment, showing that it would be a multi-generational commitment,” commented lead author Susanne Baur based at CERFACS in Toulouse.
“We would be forcing our children and their descendants to maintain a technological regime that if suddenly stopped, could be an existential threat for the planet,” she added.
The time frames set out in the paper are much longer than the carbon dioxide removal deployment lengths in 1.5°C pathways in the Intergovernmental Panel on Climate Change’s AR6 Working Group III report.
“We see that it’s a far larger commitment than scaling carbon dioxide removal to the levels needed for 1.5°C,” said Dr. Alexander Nauels, another author on the paper from research institute and CONSTRAIN partner Climate Analytics.
“It should also be mentioned that solar radiation management would do little to combat other symptoms of large amounts of CO2 in the atmosphere, like ocean acidification, which has huge ramifications for both ecosystems and the livelihoods that depend on them“, he added.