Rates at which atmospheric CO₂ is sequestered by soil organic matter, and the timescales over which it persists there, is important for understanding the role that global soils might play in mitigating or exacerbating climate change. It is also important for understanding the impact that climate change may have on soil health. We describe a new method for measuring the age of soil organic matter, rates of carbon storage, and soil carbon persistence directly in the soil profile. These accurate ages and rates of soil carbon storage may promise to yield new insights into the mechanisms by which soil carbon persists for decades to centuries, and we hope that these insights can be leveraged to better understand the interaction of global soils with climate change.