Tyler Cowen (Marginal Revolution blog), along with Alex Tabarrok, has just launched Marginal Revolution University (hat tip: Graham Brownlow). The first course they are offering is Development Economics. This is probably the most important course any finance or economics students could take as it is all about why some economies have become wealthy whilst others have become poor. The course is a series of short videos, which are well worth watching. The first lecture is below; all other lectures can be accessed at Marginal Revolution University.
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.