Now we’re 90 percent sure global warming is caused by humans, according to a major UN report just released.

[Update: And Exxon is fighting back, reports the Guardian, which writes that the AEI, an Exxon Mobil-funded thinktank, offered payments of $10,000 to scientists for articles that emphasize the report’s shortcomings. This, even as Exxon reports record profits.]

Meanwhile, California continues its lawsuit against U.S. and Japanese car manufacturers for contributing to global warming.

markporat.bmpAnd entrepreneurs forge ahead with new ideas. The organic carpet cleaning guys at Naturell are using sea-kelp to clean carpets. It cuts down on indoor air pollution (see Merc story). The Santa Clara company got a boost when search engine Google used it for two years.

And there’s Marc Porat (pictured above), a Silicon Valley entrepreneur who started at Apple, and later spun out General Magic and took it public at $800 million valuation. Now he’s transformed himself into a green entrepreneur. He has launched three companies targeting the green building market, VentureWire reported today (sub required). They are secretive, except for Quiet Solution, which has a Web site, and also a brief overview of Porat’s activities (scroll down)

Quiet Solution, backed by Rustic Canyon Partners, sells soundproofing materials. The other two are California Cement, backed by Foundation Capital, and developing a new process for cement (third leading contributor to greenhouse gas emissions, behind energy and transportation); and Global Homes, backed by Khosla Ventures, which sells sustainable pre-fabricated homes for developing markets.