In mid-2008 — six months after Gore joined the venture capital firm of Kleiner Perkins as a partner — Kleiner Perkins joined Goldman Sachs in financing a company called Terralliance — an oil exploration firm!

As Fortune reports,

Kleiner’s dirtying its hands in the oil patch was something of a head-scratcher. Back then the firm had recently hired Al Gore as a partner. But money is money, oil was trading for $140 a barrel, and Terralliance was said to have developed software that reduced the risk of drilling dry holes. It looked as if Terralliance could be a moneymaker for Kleiner, which had sunk a total of $65 million into the venture, an extraordinary sum for a VC firm — possibly its biggest single investment ever.

But less than one year later, Terralliance has faired poorly, burning through hundreds of millions of dollars, according to Fortune.

Transcript of Rep. Steve Scalise-Al Gore exchange during the April 24, 2009 House Energy and Environment Subcommittee hearing on the Waxman-Markey climate bill.