Nuclear winter is not a discredited myth. Alan Robock at Rutgers has been conducting climate simulations using a 100 Hiroshimas (~20kT) standard. This is supposedly similar to what an India-Pakistan conflict might produce.
The results are something more akin to nuclear autumn, but it results in decreased agricultural production between 5-20% in year 5 after the war. The decrease is due primarily to soot in the atmosphere. Recall that nuclear weapons are hot and this causes air to rise. There is a suction effect immediately after the blast and firestorms can form.
Simulations of a US-Russian war are more dire, and recent simulations are more in line with TAPPS. TAPPS was never discredited, its results were only somewhat moderated.
The results are something more akin to nuclear autumn, but it results in decreased agricultural production between 5-20% in year 5 after the war. The decrease is due primarily to soot in the atmosphere. Recall that nuclear weapons are hot and this causes air to rise. There is a suction effect immediately after the blast and firestorms can form.
Here's a link to a summary of results: http://ippnw.org/nuclear-famine.html
Simulations of a US-Russian war are more dire, and recent simulations are more in line with TAPPS. TAPPS was never discredited, its results were only somewhat moderated.