As this issue of the Bulletin was published, the countries of the world had just finished meeting at COP 26[1] in Glasgow, Scotland, to put forward new targets for reductions in global greenhouse gas emissions, aiming to reach a global “net zero” level by mid-century. The meeting and the national commitments to be made there are important, if the world is to avert the worst effects of climate change. Even more important, though, are practical implementations of those commitments, so they actually create the massive, real-world transition of global energy systems needed to move the world away from fossil fuels and toward energy sources that do not emit carbon dioxide.
Making such a renewable energy revolution a reality will require the greatly increased use of solar and wind energy, both of which are intermittent in nature on daily and seasonal time scales. That’s to say, electrical systems based largely or entirely on solar and wind will need to provide electricity when the sun doesn’t shine and the wind doesn’t blow. For this issue, California Institute of Technology experts Jacqueline A. Dowling and Nathan S. Lewis explore the practical options for long-term storage that could be used to make 100 percent renewable electricity reliable and affordable. Their description of emerging systems that use excess solar and wind power to produce hydrogen, which can then be stored for months or even years in salt domes and other underground structures and used to generate electricity as needed, was particularly fascinating to me, and as hopeful as anything I’ve read in the climate space for quite some time.
Given the continuing debate over nuclear power and its place in the fight against climate change, and because this is after all the Bulletin of the Atomic Scientists, our November issue contains three articles on the subject.