At a conference for green investors, Microsoft Corp. founder Bill Gates said that research funding for clean energy needs to at least double in order to see a viable, investor-attractive source of clean energy to reduce carbon emissions.
But Gates was not optimistic that the innovation would come anytime soon, saying that the United States and other countries do not adequately fund research and don't encourage experimentation by entrepreneurs.
Gates also said the likelihood of meeting clean-energy goals in the next few decades is "very daunting."
It's "difficult ... to change the energy system," Gates said at a conference in Santa Barbara. "The notion that the sector ... will be 50% non-hydrocarbons in 50 years is not possible."
The obstacle, he said, is that it takes years, sometimes decades, for ideas to translate to viable innovation.
His remarks capped a daylong slate of panelists at the Wall Street Journal's annual ECO:nomics conference, which gathers business leaders to discuss environmental policy, clean energy and business.
Many panelists -- who included Procter & Gamble Co. Chief Executive Robert McDonald and natural gas executives -- offered more optimistic timetables to reduce dependency on oil and other carbon-based energy sources. Some said the goal to derive 50% of the world's energy supply from cleaner sources would happen in the next 20 years.
Sessions throughout the conference touched on topics such as green jobs and nuclear power.
Gov. Jerry Brown is scheduled to speak Friday morning at a panel on the effect of environmental policies on the state economy.
Others in attendance included T. Boone Pickens, chairman of BP Capital Management, and actress and environmental activist Daryl Hannah, who spoke about biodiesel and other business leaders.