If there's a 10% global agricultural shortfall by 2030, will this cause >400 million fatalities?

Another question in this tournament asks Will there be a 10% global agricultural shortfall by 2024?.

Denkenberger & Pearce (2016) write:

"The uncertainty in the number of fatalities due to a 10% agricultural shortfall is very large. On the optimistic extreme, there could be aggressive government support or charity such that the vast majority of the global poor could generally afford sufficient food. If the crisis were only a year or two, loans could be feasible, either to poor individuals or poor countries. The necessary conservation (less waste, less food to animals, and so on) in the developed countries could be achieved by higher prices or rationing. However, even if mass starvation is averted, generally there would be more malnutrition and increasing susceptibility to disease. The poor would be less able to afford other lifesaving measures, and a pandemic would be more likely. Even if food aid is available, it may not be possible to get the food to the people who need it. Therefore, near zero mortality is unlikely. At the same time, even with no catastrophe, 6.5 million people die of hunger-related diseases per year (UNICEF 2006). On the other extreme, there could be food export restrictions or bans, as implemented by India, Vietnam, Egypt, and China in 2008 (Helfand 2013) when the situation was much less serious. This hoarding on a country level could also be coupled with hoarding on an individual level. This could dramatically reduce the food supply available to poor people.

Armed conflict could be in some countries’ best interest, which could also aggravate famine (Keller 1992; Waldman 2001; Goodhand 2003). These wars could even evolve into nuclear conflict, which would further impact food supplies."