The Effects of Humans on the Carbon 14 Fraction in the Atmosphere

We've had effects in both directions so burning fossil fuels lowers the carbon 14 fraction because you're pumping out super old carbon where everything is already decayed. But nuclear testing in the atmosphere increases the carbon14 fraction because it makes new carbon 14 from all this radiation. Archaeologists are frustrated by that because we were like poisoning the historical record and making it harder to figure out when things came from but geologists actually really like it because it's like a really bright signal.