Volcanic dust and changes in Northern Hemisphere temperature

Abstract

RADIATION calculations which seemed to demonstrate that changes in the temperature of the Northern Hemisphere on a wide variety of time scales could be attributed to changes in the amount of volcanic dust in the atmosphere have been reported by Pollack et al.¹. In particular, they claimed that the observed average temperature depression of 0.3 °C two years after major volcanic eruptions agreed with their calculated value and that the clearance of volcanic dust after the frequent strong eruptions at the end of the nineteenth century was responsible for a rise in the Northern Hemisphere temperature of 0.5 °C between the decades starting 1880 and 1935. Here we look critically at these two claims in the light of the known noisiness of meteorological data and the uncertainties in the estimates of volcanic dust in the atmosphere.