As the world prepares for the largest investment in nuclear power in decades, owners of uranium mines last week raised the prospect of fuel shortages. To make things worse, the reliability of estimates of the amount of uranium that can be economically mined has also been questioned.

"IF THE best way to create the future is to invent it, we say the second-best way is to finance it." John Doerr is only half joking. He is one of the most influential venture capitalists in Silicon Valley, and he knows a thing or two about financing the future. But ask him what he's focused on now and you won't hear venture-capital buzz-phrases such as "Web 2.0". These days, Doerr is firmly focused on clean technology - and in particular, energy technologies that can save the planet from global warming.