Carbon dating is debunked by increased carbon in the air. ROFL. Many Ha-ha's. No, I'm not laughing near you, I'm laughing AT you.
I bet the same Repugs that argue there is no impact from this carbon also came up with this absolutely STOOPID concept.
Even if this were plausible, look at the percentage change. Even if carbon dating is wrong by 2-3% or even 12-13%, there is still obvious proof debunking any notion that the Earth is 6000 or so years old. Lucy is over 20K years - period. You can have a margin of error created by this industrial explosion of carbon in the air of nearly 50% before you would even begin to debunk the age-date of Lucy. And, we've found things much older. With dinosaur bones, your margin of error for Carbon dating would need to be 99% before it placed the age of dinosaurs within the last 1 million years or so.
God, people - get a clue.