What happens when that enormous Antarctic ice shelf finally breaks? Eric Roston and Blacki Migliozzi on how a melting Arctic changes everything. The Arctic is in such bad shape that scientists propose refreezing it ourselves. Trump presidency “opens door” to planet-hacking geoengineer experiments. US scientists launch world’s biggest solar geoengineering study. Jeremy Baskin (Melbourne): Geoengineering, the Anthropocene and the End of Nature. Stephen Gardiner (Washington): Some Early Ethics of Geoengineering. Is it okay to tinker with the environment to fight climate change? Scientists are investigating whether releasing tons of particulates into the atmosphere might be good for the planet — not everyone thinks this is a good idea. James Temple on the growing case for geoengineering.