A new popular science book on GCRs/X-risks was just published, which summarizes the major risks (see table of contents below). It could be recommended to people until Toby Ord's book comes out.
Surprisingly, the book quotes many prominent x-risks scholars and explains some pretty complex topics very well for a pop science book (e.g. unilateralist's curse, info hazards, anthropic shadow, the Aestivation hypothesis, coherent extrapolated volition). To give you a better idea, I've copied out the first page of the index from the Amazon preview below (excuse the poor formatting).
Here's a positive review by the director of the Global Catastrophic Risks Institute.
The audiobook version makes it easy to get through (complete with the narrator imitating the accents of the people interviewed - only mildly offensive).
Table of Contents
Introduction
1. Asteroid: The Universe Is Trying To Kill Us
2. Volcano: A Decade Without A Summer
3. Nuclear: The Final Curtain On Mankind
4: Climate Change: What Do We Owe The Future?
5. Disease: Twenty-first-century Plague
6. Biotechnology: Engineering A Killer
7: Artificial Intelligence: Summoning The Demon.
8. Aliens: Where Is Everybody?
9. Survival: The Day After
10. The End: Why We Fight
INDEX
Ackerman, Thomas, active messaging, See also SETI benefits and risks of, 286 content of, 285 Drake Arecibo attempt, 284, 285 METI and, 283, 285-286 proponents of, 283 question of right to, 285-286 risk posed by, 284-285, Soviet attempt, 283-284 Advanced Aerospace Threat, Identification Program, 292 AGI. See artificial general intelligence Al. See artificial intelligence "AI winter,"246 aliens. See also SETI, artificial, 293 biological assumption, 293 chances of making contact with, 290 communication technology, 298 energy needs of, 298–299 as existential risk, 289 existential risk question of, 176-177 Fermi Paradox and, 296,297, 299, 300 fiction about, 276 germ fear and, 293 as hibernating, 299-300 as hiding, 298 indigenous population of Americas, and, 290-291 interstellar distance and, 293–294, 296, 297 malware and, 294 necrosignatures, 303-304, 305 no evidence of presence of, 298 Russian readiness for, 291-292 unifying force assumption, 288, 291 United States readiness for, 292 The War of the Worlds (Wells) and, 292-293 Allen Telescope Array, 280 Alliance to Rescue Civilization (ARC), 328 Allison, Sam K., 92 AlphaGo, 249, 257 AlphaStar, 250 AlphaZero, 249-250, 261, 264 Altman, Sam, 272 altruism, genes associated with, 334 Alvarez, Walter, 18, 22-23 Amazon Alexa, 257, 265 Ambrose, Rampino and Stanley, 61, 62 Amherst, Jeffery, 207 Amoy Gardens outbreak, 177, 178, 179 Andreessen, Marc, 236 anthrax, 208 anthropic shadow, 84, 85 anthropogenic existential risks, 6 "antibiotic apocalypse," 186 antibiotics, 4, 184, 186, 199 apocalyptic events. See also existential risk(s) Hollywood and, 23 sharing and caring and, 62 surviving, 307-326 Apocalyptic Planet (Childs), 26 Apophis, 44 Arch Mission Foundation, 329 arctic sea ice, 130 Arecibo messaging, 284, 285 "arithmetic of compassion, 100-101 Arkhipov, Vasili, 108-109, 110 Armageddon, 23, 24, 40 Armstrong, Stuart, 299 Arrhenius, Svante, 139 392
Here's an interview with the author, Bryan Walsh: https://www.vox.com/future-perfect/2019/8/29/20830793/human-extinction-end-of-the-world-end-times-bryan-walsh