Last week I was reading about Bitcoin, the open source peer-to-peer digital currency, in a technology magazine. It was predicted that Bitcoins would become an alternative to central bank issued currency as they circumvent the traditional banking and payments system. As a result, their value against the dollar had surged from $20 at the beginning of 2013 to $266 dollars yesterday. However, yesterday, after reaching this high, the price of a Bitcoin fell back to $150. Click here to see price and trading history of Bitcoin. Some experts think that these price patterns signal that there is a Bitcoin 'bubble' - see here and here.
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.