Joseph Cirincione — A regional war in say, South Asia, which involved as few as

A regional war in say, South Asia, which involved as few as one hundred nuclear bombs would result in firestorms in their urban centres that would put so much smoke and particulate into the atmosphere that the earth would be covered in a cloud that would reflect sunlight back into space and reduce global temperatures but two to three degrees for several years. This would kill most food crops on the planet, resulting in massive famines and starvation.