CO2

Patricia Mokhtarian, professor in Civil and Environmental Engineering, looks at how the addition of a big box store reduced carbon emissions in Davis, California.
While global warming shrinks ice caps, it's expanding “oxygen minimum zones,” where newly discovered bacteria are depleting waters of nitrogen, a nutrient essential to life. This could be creating imbalances.
Soil carbon stored in peat bogs may not convert to greenhouse gasses in the face of global warming.