Marine water is becoming more acidic because of the rising of atmospheric CO2 partial pressure and thats seems to be almost unknown to the public. A partnership with a middle school was established by the University of Trieste to fill the gap between research and educational system. An experimental course on global climate change and ocean acidification was offered to 14 years-old pupils. The course was experimentally based on thallus of calcareous red algae grown under different acidic conditions. Pupils also learned to use instruments, collect qualitative and numerical data and represent the data, elaborate them and take conclusion from the outcoming. In order to evaluate the project 21 students have been chosen randomly. Another 21 students, not taking part of the lessons, represent the control group. All the students have been tested at the beginning and at the conclusion of the school year (May 2010). OCSE PISA-like tests have been used to estimate previous and final skills and knowledge, and homogeneity between the two tested groups. The course represents not only a way to spread knowledge on global climatic change among the youngs, but also a tool to measure how much new methods of teaching can improve scientifical knowlegde and skills at school level.