Plants take in atmospheric carbon dioxide by photosynthesis, and are ingested by animals.
So, every living thing is constantly exchanging carbon-14 with its environment as long as it lives. The carbon in its body will remain until it decomposes or fossilizes.
So something that lived (and died) when the proportion of C was less than normal would appear to have died more years ago than it actually did (for example, it might give an age of 3,000 years before the present, rather than its true age of 2,000 years).
Radiometric dating (often called radioactive dating) is a way to find out how old something is.
Carbon combines with other elements in complex ways to form the molecules that make up our bodies.
So, scientists can estimate the age of the fossil by looking at the level of decay in its radioactive carbon.
One of these methods is based on a substance found in our bodies, plants and all living things—it’s called carbon. This makes the plant appear to have died many more years ago than it actually did (for example, the plant might appear to be, say, 3,000 years old, rather than 2,000).
C in the atmosphere haven’t been constant throughout history (for instance, Noah’s Flood lowered the total amount of available carbon by burying lots of animals and plants).
A new, more stable isotope, called the decay or daughter product, takes its place.
It’s important that we allow God’s written record of history, the Bible, to guide our thinking about the past—this includes our understanding of the age of the Earth/universe How many times have you heard something like, “This animal lived 50,000 years ago”, or “This person died 20,000 years ago’?