How to address solar geoengineering’s transparency problem

In 2010, climate scientists gathered at the Asilomar Conference Center in California, in a convening that echoed a legendary 1975 meeting in which a scientific committee came together in a exercise of self-governance to create guidelines for recombinant DNA, which many at the time feared could have unintended negative impacts on the environment and possibly on human health.The climate scientists 15 years ago had a similar ethical challenge: to provide research principles for solar geoengineering.They realized that the idea of deliberately reflecting a small fraction of incoming sunlight to cool Earth would require higher levels of trust and governance than other kinds of climate research.Climate journalist Jeff Goodell, who attended the 2010 meeting, noted that he may have "witnessed the birth of something new-call it the conscience of a geoengineer" (1).Despite the consensus of the scholarly literature (see SI Appendix, Table S1 for a summary of the numerous discussions on principles and codes of conduct in geoengineering), there are still no established practices around transparency, let alone regulations demanding it.Rather, we have the opposite: private companies such as Make Sunsets, a US-based company that sells "cooling credits" and has been releasing toxic sulfur balloons ( 2 ) since 2022, or Stardust, the Israeli startup with $15 million of venture capital funding ( 3 ).Few seem to know quite what they are doing.What happened to the conscience of the geoengineer?Decision-makers and members of the general public need to know that geoengineering research is legitimate, which means that findings are robust, contrary results aren't hidden, and investigations are free from conflicts of interest.This applies as much to "outdoor" research as it does to modeling and laboratory work, where the idea of geoengineering is shaped.If people are going to evaluate whether