ScienceDaily: A University of Oklahoma-led study links vast amounts of iron-rich dust deposits from the late Paleozoic period of 300 million years ago with implications for major ecosystem fertilization and a massive drawdown of atmospheric carbon. Understanding iron fertilization and other deep-time events may explain present and future climate change and aid scientists and policymakers when making decisions related to geoengineering Earth. "Humans are now a geologic force on the planet, meaning our activities...