You don't understand.

There have been a combined total of 540,000 kt of nuclear explosions across 2500 tests. Sedan was a shallow buried 110 kt explosion that excavated 11,000,000 tons of material. There are currently around 3000 deployed nuclear weapons. Assuming that ALL detonations in an nuclear exchange were buried to maximize material excavated, (an insane assumption) they would excavate around 5x10^10 tons of material. That is on the same order of magnitude of the 1991 eruption of Mount Pinatubo, which ejected 1.1x10^10 tons of material.

Global temperatures dropped by about 0.5 °C (0.9 °F) in the years 1991–1993

Even if we assumed that 5 times the material gives a 5 times the reduction in temperature (it doesn't, see the Mount Tambora eruption of 1815), that is still only 2 degrees.

Nuclear winter is pure fear mongering. It does not exist.

You don't understand.

There have been a combined total of 540,000 kt of nuclear explosions across 2500 tests. Sedan was a shallow buried 110 kt explosion that excavated 11,000,000 tons of material. There are currently around 3000 deployed nuclear weapons. Assuming that ALL detonations in an nuclear exchange were buried to maximize material excavated, (an insane assumption) they would excavate around 5x10^10 tons of material. That is on the same order of magnitude of the 1991 eruption of Mount Pinatubo, which ejected 1.1x10^10 tons of material.

Global temperatures dropped by about 0.5 °C (0.9 °F) in the years 1991–1993

Even if we assumed that 5 times the material gives a 5 times the reduction in temperature (it doesn't), that is still only 2 degrees.

Nuclear winter is pure fear mongering. It does not exist.