It's called the "greenhouse effect" because the CO2 traps heat in the earth's atmosphere, just like the walls and roof of a greenhouse trap the heat inside the greenhouse. Greenhouses are also enriched with extra CO2 to boost yields, but that's not why it's called the "greenhouse effect"
Sort of a misquote. The Bloomberg article quotes the Google Ventures managing partner, who says the long-term market value could be $200 billion or more. This article makes it sound like that's their current valuation. Still sounds too high, but it's not quite as ridiculous.