Dealing with climate change might mean tinkering with the oceans and the atmosphere. Those who could do so would like the regulations to be clear

IN 1975 scientists expert in a new and potentially world-changing technology, genetic engineering, gathered at Asilomar, on the Monterey peninsula in California, to ponder the ethics and safety of the course they were embarking on. The year before, they had imposed on themselves a voluntary moratorium on experiments which involved the transfer of genes from one species to another, amid concerns about the risk to human health and to the environment which such “transgenic” creations might pose. That decision gave the wider world confidence that the emerging field of biotechnology was taking its responsibilities seriously, which meant that the Asilomar conference was able to help shape a safety regime that allowed the moratorium to be lifted. That, in turn, paved the way for the subsequent boom in molecular biology and biotechnology.

Another bunch of researchers, accompanied by policy experts, social scientists and journalists, gathered in Asilomar between March 22nd and 26th, hoped for a similar outcome to their deliberations. This time the topic under discussion was not genetic engineering but geoengineering—deliberately rather than accidentally changing the world’s environment. …