How do natural disasters affect climate?
One example is volcanic explosions.
When Krakatoa exploded in 1883 the entire world experienced a number of years of unusually cold weather, due to the volcanic dust in the atmosphere. The average temperature in England dropped more than 2 degrees. Temperatures did not return to normal until 1888.
Another volcanic explosion in Indonsia of Mount Tambora in 1815 resulted in the year with no summer. The amount of volcanic dust blocked the sun's rays from reaching and warming the earth. The summer after the explosion was cold throughout the world.
One theory is that the dinosaurs died because of increased volcanic activity due to unusually rapid movement of the tectonic plates. The high volcanic activity created a colder climate than the large cold blooded dinosaurs could quickly adapt to.
Volcanic activity can quickly change the climate of the world.