For electric power generation, we are very optimistic about solar-thermal technology, and we’re intrigued by the potential of enhanced geothermal energy to replace coal-based power generation. Traditional carbon capture and sequestration-based coal power generation is somewhat unlikely to be competitive.

In my view, it’s irreverence, foolish confidence and naivety combined with persistence, open mindedness and a continual ability to learn that created Facebook, Google, Yahoo, eBay, Microsoft, Apple, Juniper, AOL, Sun Microsystems and others.

There's no doubt in my mind over the next 25 years how we drive, how we build our houses, how we fly, how we build our buildings, will all change.

Startups allow technologists and scientists to take risks and change plans in a way that would be frowned upon in a big company. Having said that, big companies will play a key role in certain areas and in partnerships with little companies. Each has its strengths.

Letting the perfect be the enemy of the good is one of the reasons we have a coal-dependent infrastructure, with the resulting environmental impact that all of us can see. I suspect environmentalists, through their opposition of nuclear power, have caused more coal plants to be built than anybody. And those coal plants have emitted more radioactive material from the coal than any nuclear accident would have.

Setting an aggressive enough carbon-reduction goal will result in an appropriate price for carbon and will help many a renewable technology. Consumer education will help. Most importantly, though, will be the continually declining cost trajectory of the real breakthrough in clean-technology costs driven by research and innovation. In the end, private capital is the real barometer of change.

Spreadsheets are fiction. Believing in what you're doing and what you're building is what's important.