“In a sense, geoengineering has always been on the table as a possible response to climate change. As early as 1965, the U.S. President’s Science Advisory Committee warned, in a report called Restoring the Quality of Our Environment, that CO2 emissions were modifying the Earth’s heat balance.12 That report, regarded as the first high-level acknowledgment of climate change, went on to recommend – not emissions reductions, but a suite of geoengineering options. The authors of the report asserted, “The possibilities of deliberately bringing about countervailing climatic changes…need to be thoroughly explored” and suggested that reflective particles could be dispersed on tropical seas (at an annual cost of around $500 million), which might also inhibit hurricane formation.”