The most important mode of instruction in university is the lecture. This is where a professor gives their unique perspective on the subject. Miss the lecture and you miss the message. PowerPoint lecture outlines give students a partial and sometimes distorted view of the lecture. However, in most UK universities lecture attendance is not compulsory whereas tutorial attendance is. Click here to read an interesting student post at the Guardian which argues that lectures should be made compulsory.
The Berkeley Earth Project , an independent study of global warming, has found that the earth has become a degree warmer over the past half century. However, the statistical uncertainty surrounding pre-1920 estimates makes it very hard to say much about long-term trends - click here for graph . This is one of my concerns with the global warming debate - we simply don't have trustworthy long-run data which looks at temperature changes over the last millennium (or two). My second concern with the global warming debate is that it is very hard to prove any sort of casual link between global warming and human activity. The scientists may be able to show correlation between global warming and our production of carbon dioxides etc., but correlation is not causation. My third concern with the debate is that those who are sceptical or agnostic are stereotyped as flat-earthers or intellectually-challenged crackpots. This only stifles debate and the progress of science itself.