The earth has a magnetic field around it which helps protect us from harmful radiation from outer space. The stronger the field is around the earth, the fewer the number of cosmic rays that are able to reach the atmosphere.
This would result in a smaller production of The cause for the long term variation of the C-14 level is not known.
Many people have been led to believe that radiometric dating methods have proved the earth to be billions of years old.The procedures used are not necessarily in question. The secular (evolutionary) worldview interprets the universe and world to be billions of years old. The use of carbon-14 dating is often misunderstood.Carbon-14 is mostly used to date once-living things (organic material). Carbon-14 is constantly being added to the atmosphere.Note that, contrary to a popular misconception, carbon dating is not used to date rocks at millions of years old.
Before we get into the details of how radiometric dating methods are used, we need to review some preliminary concepts from chemistry.So, a carbon atom might have six neutrons, or seven, or possibly eight—but it would always have six protons.