A large asteroid or comet impact, super volcanic eruption, or full-scale nuclear war could cause a ~100% global agricultural shortfall. Together these have a probability ~10% this century. We have proposed solutions that could feed everyone without the sun, such as growing mushrooms on dead trees. Abrupt climate change, coincident extreme weather, a volcanic eruption like that which caused the year without a summer in 1816, regional nuclear war, complete loss of bees, and medium-sized comet/asteroid could cause a ~10% global agricultural shortfall. Together these have a probability ~80% this century.
We have proposed solutions that would mitigate the food price rise, such as relocating animals to the farm fields so they can consume agricultural residues. A number of risks could cause widespread electrical failure, including a series of high-altitude electromagnetic pulses (HEMPs) caused by nuclear weapons, an extreme solar storm, and a coordinated cyber attack. Since modern industry depends on electricity, it is likely there would be a collapse of the functioning of industry and machines in these scenarios. We have proposed solutions for food (e.g. burning wood from landfills for fertilizer) and nonfood (such as retrofitting ships to be wind powered) requirements of everyone. These alternate food solutions require only low-cost preparation research and planning (unlike storing food), and therefore are cost-effective ways of saving expected lives and reducing the chance of loss of civilization, from which humanity may not recover.
Dr. David Denkenberger received his B.S. from Penn State in Engineering Science, his M.S.E. from Princeton in Mechanical and Aerospace Engineering, and his Ph.D. from the University of Colorado at Boulder in the Building Systems Program. His dissertation was on his patent-pending expanded microchannel heat exchanger. He is an assistant professor at Tennessee State University in architectural engineering. He is also an associate at the Global Catastrophic Risk Institute. He received the National Merit Scholarship, the Barry Goldwater Scholarship, the National Science Foundation Graduate Research Fellowship, and is a Penn State distinguished alumnus. He has authored or co-authored over 50 publications, including the book Feeding Everyone no Matter What: Managing Food Security after Global Catastrophe. He has given over 80 technical presentations.