Mr. Bonds has been accused using performance enhancing drugs, yet the data clearly shows that there is a better explanation.
When CO2 levels were low in the year 1876, the most home runs anyone could come up with in a single season was 5. But by the year 2001, atmospheric CO2 levels were so high that Barry Bonds was able to hit 73 of them. The graph below plots home run records vs. CO2. and leaves little doubt that correlation is equivalent to causation.
Mr. Bonds needs a new lawyer. I recommend this guy, who is a CO2 expert and will soon be looking for work. He has already correlated nearly everything on the planet with CO2, and has shown some skill at working numbers.