At times during the past half-billion years, carbon dioxide warmed our planet more than previously thought, according to a new reconstruction of Earth’s deep past. At times during the past half-billion years, carbon dioxide warmed our planet more than previously thought, according to a new reconstruction of Earth’s deep past. Global Warming, Greenhouse Gas Emissions, Science (Journal), Research, Carbon Dioxide, Paleontology, Earth, Smithsonian Institution NYT > Science