The scientific and political debate concerning global warming and carbon emissions is gaining momentum this week with claims and counter claims surrounding the factual evidence available. There is certainly evidence that global warming is real and happening, but how much of the scientific data is selective? The role of a scientist is to critically evaluate all data offered, but do remember that financial support for scientific research may bias that data. I am following this debate with interest, as I feel that there is a political agenda as well as a scientific agenda. Also remember that global warming and climate change features heavily in the current A2 syllabus and that marking schemes will focus on the evidence given in the textbooks. Whatever the state of play in the newspapers and journals mid January, and whatever your personal opinion, it will be better to play safe and answer exam questions in such a way that the examiner will be able to award you some marks!