Fossil fuels like coal, oil and natural gas supply 80 percent of the world’s energy to warm homes, charge devices and power transportation. They are also the primary human source of greenhouse gas emissions. Stanford scientists broadly agree that curtailing our use of fossil fuels would have significant benefits – like improving health and reducing the number and severity of natural disasters – but it’s not yet clear what can replace them.

Wind and solar are increasingly popular sources of energy, but the sun does not always shine, and the wind doesn’t always blow. Batteries to store their intermittent energy are not yet cheap and powerful enough to fill the gaps. Nuclear energy produces no greenhouse gases directly, but the current generation of reactors has other problems. Solutions like storing carbon dioxide underground or turning it into clean fuel are promising, but they also need much development. None of the possible solutions is without challenges.

Eight Stanford researchers describe how, among these many developing options, they envision the world becoming less reliant on fossil fuels. Nobel physicist and former U.S. Secretary of Energy Steven Chu, a professor of physics and of cellular and molecular biology at Stanford, outlines the broad challenge, “which cannot be overestimated,” he says. Other professors describe pathways to better technologies, as well as the public policies and financial mechanisms necessary for the best applications to flourish. All agree that the goal is less reliance on carbon-based fuel sources, and that a combination of solutions – rather than a silver bullet – likely will create that greener energy future.