Fossil fuels have driven rising prosperity for more than 200 years and today provide 80 percent of human energy needs. But carbon dioxide emissions from their use threaten potentially catastrophic climate change. To avoid that we must achieve net zero emissions across the whole world by around 2060. That may seem daunting. But it would be undoubtedly technically possible at very small economic cost, as a report from the Energy Transitions Commission makes clear.
The issue is not feasibility, but whether governments, industry and consumers are willing to take the actions required to get there. Achieving net zero emissions requires boosting the role of electricity. The commission, which I chair, estimates its share of energy demand must grow from 20 percent today to more than 60 percent by mid-century. Total generation would have to rise from 20,000 terawatt hours to up to 100,000 twh. Nuclear power could play some role but most of this power must and can come from renewable sources, including wind, solar and water.
Less than 1.5 percent of the global land surface area could produce all the renewable electricity the world needs: and it is physically possible to run grids that rely on intermittent renewables for 85 to 90 percent of their power, while still delivering electricity whenever needed. The real challenge is to get to this endpoint fast enough: that requires us to quintuple our annual investment in renewables capacity for the next 40 years. Three other technologies are also essential.
First, there must be a major role for hydrogen power: steel producers could potentially use it rather than coking coal as the reduction agent, and ammonia (produced from hydrogen) could be used as fuel for ships. Hydrogen can result in zero-carbon emissions if produced via electrolysis using zero-carbon electricity. Second, we must tap bioenergy to provide zero-carbon aviation fuel and as a feedstock for plastics production. But this step must be carefully managed to avoid harmful impacts on ecosystems and food production. Third a relatively small but still vital role for technologies that capture CO2, particularly in cement production.