InsideClimate: Many people are by now familiar with the Keeling curve, a graph showing the steady increase in carbon dioxide in the atmosphere measured over decades by the Mauna Loa Observatory, the world's longest-running CO2 monitoring station. The research, started by renowned climate scientist Dave Keeling in 1958, is considered one of the pillars of the scientific consensus that human activity is the main driver of climate change. This year, the data revealed a troubling milestone: CO2 concentrations had...