Scientists and researchers are considering refracting most of the sunlight back to space with the help of solar geoengineering. It was stated in a March report by the U.S. National Academies of Sciences, Engineering, and Medicine (NASEM) that more focus and investment are needed for solar geoengineering. However, there is still doubt if it will create more problems than solve them.
IPCC’s latest report called “code red for humanity” by UN Secretary-General António Guterres suggests there is a need for dire methods to alleviate the climate crisis and this seems to be like it. It is predicted that a 4 °C rise in temperature will be experienced by the end of the century. This suggests that the Paris Agreement, 2015, will be failed.
In an interview with Physics Today, Chris Field, an environmental scientist at Stanford University who chaired the NASEM committee behind the report recently said “we are in a critical time for tackling climate change. We know it’s difficult to make societal changes to get to zero greenhouse gas emissions. That difficulty provides a compelling motivation to understand the full portfolio of options.”
The Union of Concerned Scientists (UCS) highlights the risk of “moral hazard.” Currently, the knowledge about a sustained solar geoengineering drive will have the potential to affect regional weather patterns it requires millions to study and understand the process. In the end, it might be concluded that the method is not safe enough.
Stratospheric aerosol injection (SAI), comprising spraying reflecting particles, aerosols, into the upper atmosphere, and marine cloud brightening (MCB), using sea salt to encourage added cloud formation over the ocean are the two methods to achieve solar geoengineering right now.
Bill Gates-backed a proposal by Harvard scientists to carry out an experiment testing the viability of SAI. The scientists behind the experiment called the Stratospheric Controlled Perturbation Experiment (SCoPEx), postponed a test flight scheduled for this year citing an outcry from environmentalists.
The experiment will cost around $20 million and 2 Kg of will be emitted into the stratosphere. There are controversies attached to the topic, still something needs to be done as the planet is reaching record-breaking temperatures.