Flying between London and Paris causes ten times more CO2 than the train

If you're traveling between continental Europe and Britain and care about the environment, you might want to consider alternatives to flying. Since there are no bridges across the English Channel, that leaves the channel tunnel and the EuroStar train as the only option, (unless you're a really strong swimmer).
The EuroStar web-site has a chart that estimates the carbon dioxide emissions associated with traveling between London and Paris or Brussels by train and by air. Their analysis shows that train travel emits about one tenth of the emissions compared to flying. The analysis apparently factors in power plant emissions and transmission losses to compare the electric trains to the jets.

[Source: EuroStar via Hugg]