We recently quantified how the climate change caused by atmospheric soot loadings from nuclear weapon detonation would limit terrestrial and aquatic food production. We used one climate model, one crop model, and one fishery model to estimate the impacts from six scenarios of stratospheric soot injection, predicting the total food calories available in each nation post-war after stored food was consumed. We estimated that more than 2 billion people could die from nuclear war between India and Pakistan, and more than 5 billion could die from a war between the United States and Russia. We propose to work with other scientific teams to refine and advance our work by using multiple climate and crop models, and addressing changes in the availability of fuel, fertilizer, and agricultural infrastructure, the effects of radioactive contamination, adaptation measures such as planting different crops, and assumptions about food distribution within nations and trade between nations. We will create software for nuclear states to use so they can calculate and avoid civilian deaths depending on how they plan to use nuclear weapons. We will communicate our results with talks, publications, and social media, to inform public policy of the consequences of any use of nuclear weapons.