Equilibrium assignment

[Amelia.hatch]

Hi,
I am really confused about an assignment that I have to do for chemistry. It's on the equilibrium reactions that occur in our oceans, particularly the absorbance of CO2 from the atmosphere into the water where it reacts with H2O to form carbonic acid. Throughout history the increasing amounts of carbon dioxide humans produce have meant that the ocean has absorbed more and more CO2 and therefore created more carbonic acid. The hydrogen ions detach from the carbonic acid, making the ocean more acidic. This is how the ocean has slowed down climate change, however, in recent years the increase in temperatures due to global warming has meant that the oceans are absorbing less and less CO2. The background information surrounding this makes sense but for the assignment I had to do an experiment of my own. For my experiment I measured the pH of carbonated water at different temperatures to see the effect that temperature would have. I found that increasing the temperature increased the acidity of the water. How is this possible when the water is absorbing less CO2 and therefore creating less carbonic acid which in turn means less free hydrogen ions?

Here are my results.   
Temperature     5Co   15Co   25Co   35Co   45Co
Average pH   2.957   2.821   2.440   2.255   2.038

If anyone could help me out with this I would be so grateful